Video quality assessment using motion-compensated temporal filtering and manifold feature similarity
Yu, Mei; Jiang, Gangyi; Shao, Feng; Peng, Zongju
2017-01-01
Well-performed Video quality assessment (VQA) method should be consistent with human visual systems for better prediction accuracy. In this paper, we propose a VQA method using motion-compensated temporal filtering (MCTF) and manifold feature similarity. To be more specific, a group of frames (GoF) is first decomposed into a temporal high-pass component (HPC) and a temporal low-pass component (LPC) by MCTF. Following this, manifold feature learning (MFL) and phase congruency (PC) are used to predict the quality of temporal LPC and temporal HPC respectively. The quality measures of the LPC and the HPC are then combined as GoF quality. A temporal pooling strategy is subsequently used to integrate GoF qualities into an overall video quality. The proposed VQA method appropriately processes temporal information in video by MCTF and temporal pooling strategy, and simulate human visual perception by MFL. Experiments on publicly available video quality database showed that in comparison with several state-of-the-art VQA methods, the proposed VQA method achieves better consistency with subjective video quality and can predict video quality more accurately. PMID:28445489
Layer-based buffer aware rate adaptation design for SHVC video streaming
NASA Astrophysics Data System (ADS)
Gudumasu, Srinivas; Hamza, Ahmed; Asbun, Eduardo; He, Yong; Ye, Yan
2016-09-01
This paper proposes a layer based buffer aware rate adaptation design which is able to avoid abrupt video quality fluctuation, reduce re-buffering latency and improve bandwidth utilization when compared to a conventional simulcast based adaptive streaming system. The proposed adaptation design schedules DASH segment requests based on the estimated bandwidth, dependencies among video layers and layer buffer fullness. Scalable HEVC video coding is the latest state-of-art video coding technique that can alleviate various issues caused by simulcast based adaptive video streaming. With scalable coded video streams, the video is encoded once into a number of layers representing different qualities and/or resolutions: a base layer (BL) and one or more enhancement layers (EL), each incrementally enhancing the quality of the lower layers. Such layer based coding structure allows fine granularity rate adaptation for the video streaming applications. Two video streaming use cases are presented in this paper. The first use case is to stream HD SHVC video over a wireless network where available bandwidth varies, and the performance comparison between proposed layer-based streaming approach and conventional simulcast streaming approach is provided. The second use case is to stream 4K/UHD SHVC video over a hybrid access network that consists of a 5G millimeter wave high-speed wireless link and a conventional wired or WiFi network. The simulation results verify that the proposed layer based rate adaptation approach is able to utilize the bandwidth more efficiently. As a result, a more consistent viewing experience with higher quality video content and minimal video quality fluctuations can be presented to the user.
Video quality assessment using a statistical model of human visual speed perception.
Wang, Zhou; Li, Qiang
2007-12-01
Motion is one of the most important types of information contained in natural video, but direct use of motion information in the design of video quality assessment algorithms has not been deeply investigated. Here we propose to incorporate a recent model of human visual speed perception [Nat. Neurosci. 9, 578 (2006)] and model visual perception in an information communication framework. This allows us to estimate both the motion information content and the perceptual uncertainty in video signals. Improved video quality assessment algorithms are obtained by incorporating the model as spatiotemporal weighting factors, where the weight increases with the information content and decreases with the perceptual uncertainty. Consistent improvement over existing video quality assessment algorithms is observed in our validation with the video quality experts group Phase I test data set.
Academic podcasting: quality media delivery.
Tripp, Jacob S; Duvall, Scott L; Cowan, Derek L; Kamauu, Aaron W C
2006-01-01
A video podcast of the CME-approved University of Utah Department of Biomedical Informatics seminar was created in order to address issues with streaming video quality, take advantage of popular web-based syndication methods, and make the files available for convenient, subscription-based download. An RSS feed, which is automatically generated, contains links to the media files and allows viewers to easily subscribe to the weekly seminars in a format that guarantees consistent video quality.
Scalable gastroscopic video summarization via similar-inhibition dictionary selection.
Wang, Shuai; Cong, Yang; Cao, Jun; Yang, Yunsheng; Tang, Yandong; Zhao, Huaici; Yu, Haibin
2016-01-01
This paper aims at developing an automated gastroscopic video summarization algorithm to assist clinicians to more effectively go through the abnormal contents of the video. To select the most representative frames from the original video sequence, we formulate the problem of gastroscopic video summarization as a dictionary selection issue. Different from the traditional dictionary selection methods, which take into account only the number and reconstruction ability of selected key frames, our model introduces the similar-inhibition constraint to reinforce the diversity of selected key frames. We calculate the attention cost by merging both gaze and content change into a prior cue to help select the frames with more high-level semantic information. Moreover, we adopt an image quality evaluation process to eliminate the interference of the poor quality images and a segmentation process to reduce the computational complexity. For experiments, we build a new gastroscopic video dataset captured from 30 volunteers with more than 400k images and compare our method with the state-of-the-arts using the content consistency, index consistency and content-index consistency with the ground truth. Compared with all competitors, our method obtains the best results in 23 of 30 videos evaluated based on content consistency, 24 of 30 videos evaluated based on index consistency and all videos evaluated based on content-index consistency. For gastroscopic video summarization, we propose an automated annotation method via similar-inhibition dictionary selection. Our model can achieve better performance compared with other state-of-the-art models and supplies more suitable key frames for diagnosis. The developed algorithm can be automatically adapted to various real applications, such as the training of young clinicians, computer-aided diagnosis or medical report generation. Copyright © 2015 Elsevier B.V. All rights reserved.
Full-frame video stabilization with motion inpainting.
Matsushita, Yasuyuki; Ofek, Eyal; Ge, Weina; Tang, Xiaoou; Shum, Heung-Yeung
2006-07-01
Video stabilization is an important video enhancement technology which aims at removing annoying shaky motion from videos. We propose a practical and robust approach of video stabilization that produces full-frame stabilized videos with good visual quality. While most previous methods end up with producing smaller size stabilized videos, our completion method can produce full-frame videos by naturally filling in missing image parts by locally aligning image data of neighboring frames. To achieve this, motion inpainting is proposed to enforce spatial and temporal consistency of the completion in both static and dynamic image areas. In addition, image quality in the stabilized video is enhanced with a new practical deblurring algorithm. Instead of estimating point spread functions, our method transfers and interpolates sharper image pixels of neighboring frames to increase the sharpness of the frame. The proposed video completion and deblurring methods enabled us to develop a complete video stabilizer which can naturally keep the original image quality in the stabilized videos. The effectiveness of our method is confirmed by extensive experiments over a wide variety of videos.
Exploring the explaining quality of physics online explanatory videos
NASA Astrophysics Data System (ADS)
Kulgemeyer, Christoph; Peters, Cord H.
2016-11-01
Explaining skills are among the most important skills educators possess. Those skills have also been researched in recent years. During the same period, another medium has additionally emerged and become a popular source of information for learners: online explanatory videos, chiefly from the online video sharing website YouTube. Their content and explaining quality remain to this day mostly unmonitored, as well is their educational impact in formal contexts such as schools or universities. In this study, a framework for explaining quality, which has emerged from surveying explaining skills in expert-novice face-to-face dialogues, was used to explore the explaining quality of such videos (36 YouTube explanatory videos on Kepler’s laws and 15 videos on Newton’s third law). The framework consists of 45 categories derived from physics education research that deal with explanation techniques. YouTube provides its own ‘quality measures’ based on surface features including ‘likes’, views, and comments for each video. The question is whether or not these measures provide valid information for educators and students if they have to decide which video to use. We compared the explaining quality with those measures. Our results suggest that there is a correlation between explaining quality and only one of these measures: the number of content-related comments.
Mackenzie, Colin F; Pasley, Jason; Garofalo, Evan; Shackelford, Stacy; Chen, Hegang; Longinaker, Nyaradzo; Granite, Guinevere; Pugh, Kristy; Hagegeorge, George; Tisherman, Samuel A
2017-07-01
Unbiased evaluation of trauma core competency procedures is necessary to determine if residency and predeployment training courses are useful. We tested whether a previously validated individual procedure score (IPS) for individual procedure vascular exposure and fasciotomy (FAS) performance skills could discriminate training status by comparing IPS of evaluators colocated with surgeons to blind video evaluations. Performance of axillary artery (AA), brachial artery (BA), and femoral artery (FA) vascular exposures and lower extremity FAS on fresh cadavers by 40 PGY-2 to PGY-6 residents was video-recorded from head-mounted cameras. Two colocated trained evaluators assessed IPS before and after training. One surgeon in each pretraining tertile of IPS for each procedure was randomly identified for blind video review. The same 12 surgeons were video-recorded repeating the procedures less than 4 weeks after training. Five evaluators independently reviewed all 96 randomly arranged deidentified videos. Inter-rater reliability/consistency, intraclass correlation coefficients were compared by colocated versus video review of IPS, and errors. Study methodology and bias were judged by Medical Education Research Study Quality Instrument and the Quality Assessment of Diagnostic Accuracy Studies criteria. There were no differences (p ≥ 0.5) in IPS for AA, FA, FAS, whether evaluators were colocated or reviewed video recordings. Evaluator consistency was 0.29 (BA) - 0.77 (FA). Video and colocated evaluators were in total agreement (p = 1.0) for error recognition. Intraclass correlation coefficient was 0.73 to 0.92, dependent on procedure. Correlations video versus colocated evaluations were 0.5 to 0.9. Except for BA, blinded video evaluators discriminated (p < 0.002) whether procedures were performed before training versus after training. Study methodology by Medical Education Research Study Quality Instrument criteria scored 15.5/19, Quality Assessment of Diagnostic Accuracy Studies 2 showed low bias risk. Video evaluations of AA, FA, and FAS procedures with IPS are unbiased, valid, and have potential for formative assessments of competency. Prognostic study, level II.
Baek, Sunyong; Im, Sun Ju; Lee, Sun Hee; Kam, Beesung; Yune, So Joung; Lee, Sang Soo; Lee, Jung A; Lee, Yuna; Lee, Sang Yeoup
2011-12-01
The lecture is a technique for delivering knowledge and information cost-effectively to large medical classes in medical education. The aim of this study was to analyze teaching quality, based on triangle analysis of video recordings of medical lectures, to strengthen teaching competency in medical school. The subjects of this study were 13 medical professors who taught 1st- and 2nd-year medical students and agreed to a triangle analysis of video recordings of their lectures. We first performed triangle analysis, which consisted of a professional analysis of video recordings, self-assessment by teaching professors, and feedback from students, and the data were crosschecked by five school consultants for reliability and consistency. Most of the distress that teachers experienced during the lecture occurred in uniform teaching environments, such as larger lecture classes. Larger lectures that primarily used PowerPoint as a medium to deliver information effected poor interaction with students. Other distressing factors in the lecture were personal characteristics and lack of strategic faculty development. Triangle analysis of video recordings of medical lectures gives teachers an opportunity and motive to improve teaching quality. Faculty development and various improvement strategies, based on this analysis, are expected to help teachers succeed as effective, efficient, and attractive lecturers while improving the quality of larger lecture classes.
Video quality assessment method motivated by human visual perception
NASA Astrophysics Data System (ADS)
He, Meiling; Jiang, Gangyi; Yu, Mei; Song, Yang; Peng, Zongju; Shao, Feng
2016-11-01
Research on video quality assessment (VQA) plays a crucial role in improving the efficiency of video coding and the performance of video processing. It is well acknowledged that the motion energy model generates motion energy responses in a middle temporal area by simulating the receptive field of neurons in V1 for the motion perception of the human visual system. Motivated by the biological evidence for the visual motion perception, a VQA method is proposed in this paper, which comprises the motion perception quality index and the spatial index. To be more specific, the motion energy model is applied to evaluate the temporal distortion severity of each frequency component generated from the difference of Gaussian filter bank, which produces the motion perception quality index, and the gradient similarity measure is used to evaluate the spatial distortion of the video sequence to get the spatial quality index. The experimental results of the LIVE, CSIQ, and IVP video databases demonstrate that the random forests regression technique trained by the generated quality indices is highly correspondent to human visual perception and has many significant improvements than comparable well-performing methods. The proposed method has higher consistency with subjective perception and higher generalization capability.
Measuring perceived video quality of MPEG enhancement by people with impaired vision
Fullerton, Matthew; Woods, Russell L.; Vera-Diaz, Fuensanta A.; Peli, Eli
2007-01-01
We used a new method to measure the perceived quality of contrast-enhanced motion video. Patients with impaired vision (n = 24) and normally-sighted subjects (n = 6) adjusted the level of MPEG-based enhancement of 8 videos (4 minutes each) drawn from 4 categories. They selected the level of enhancement that provided the preferred view of the videos, using a reducing-step-size staircase procedure. Most patients made consistent selections of the preferred level of enhancement, indicating an appreciation of and a perceived benefit from the MPEG-based enhancement. The selections varied between patients and were correlated with letter contrast sensitivity, but the selections were not affected by training, experience or video category. We measured just noticeable differences (JNDs) directly for videos, and mapped the image manipulation (enhancement in our case) onto an approximately linear perceptual space. These tools and approaches will be of value in other evaluations of the image quality of motion video manipulations. PMID:18059909
VideoBeam portable laser communicator
NASA Astrophysics Data System (ADS)
Mecherle, G. Stephen; Holcomb, Terry L.
1999-01-01
A VideoBeamTM portable laser communicator has been developed which provides full duplex communication links consisting of high quality analog video and stereo audio. The 3.2-pound unit resembles a binocular-type form factor and has an operational range of over two miles (clear air) with excellent jam-resistance and low probability of interception characteristics. The VideoBeamTM unit is ideally suited for numerous military scenarios, surveillance/espionage, industrial precious mineral exploration, and campus video teleconferencing applications.
Study of Temporal Effects on Subjective Video Quality of Experience.
Bampis, Christos George; Zhi Li; Moorthy, Anush Krishna; Katsavounidis, Ioannis; Aaron, Anne; Bovik, Alan Conrad
2017-11-01
HTTP adaptive streaming is being increasingly deployed by network content providers, such as Netflix and YouTube. By dividing video content into data chunks encoded at different bitrates, a client is able to request the appropriate bitrate for the segment to be played next based on the estimated network conditions. However, this can introduce a number of impairments, including compression artifacts and rebuffering events, which can severely impact an end-user's quality of experience (QoE). We have recently created a new video quality database, which simulates a typical video streaming application, using long video sequences and interesting Netflix content. Going beyond previous efforts, the new database contains highly diverse and contemporary content, and it includes the subjective opinions of a sizable number of human subjects regarding the effects on QoE of both rebuffering and compression distortions. We observed that rebuffering is always obvious and unpleasant to subjects, while bitrate changes may be less obvious due to content-related dependencies. Transient bitrate drops were preferable over rebuffering only on low complexity video content, while consistently low bitrates were poorly tolerated. We evaluated different objective video quality assessment algorithms on our database and found that objective video quality models are unreliable for QoE prediction on videos suffering from both rebuffering events and bitrate changes. This implies the need for more general QoE models that take into account objective quality models, rebuffering-aware information, and memory. The publicly available video content as well as metadata for all of the videos in the new database can be found at http://live.ece.utexas.edu/research/LIVE_NFLXStudy/nflx_index.html.
Spatial resampling of IDR frames for low bitrate video coding with HEVC
NASA Astrophysics Data System (ADS)
Hosking, Brett; Agrafiotis, Dimitris; Bull, David; Easton, Nick
2015-03-01
As the demand for higher quality and higher resolution video increases, many applications fail to meet this demand due to low bandwidth restrictions. One factor contributing to this problem is the high bitrate requirement of the intra-coded Instantaneous Decoding Refresh (IDR) frames featuring in all video coding standards. Frequent coding of IDR frames is essential for error resilience in order to prevent the occurrence of error propagation. However, as each one consumes a huge portion of the available bitrate, the quality of future coded frames is hindered by high levels of compression. This work presents a new technique, known as Spatial Resampling of IDR Frames (SRIF), and shows how it can increase the rate distortion performance by providing a higher and more consistent level of video quality at low bitrates.
2010-03-01
piece of tissue. Full Mobility Manipulator Robot The primary challenge with the design of a full mobility robot is meeting the competing design...streamed through an embedded plug-in for VLC player using asf/wmv encoding with 200ms buffering. A benchtop test of the remote user interface was...encountered in ensuring quality video is being made available to the surgeon. A significant challenge has been to consistently provide high quality video
Naval Research Laboratory 1984 Review.
1985-07-16
pulsed infrared comprehensive characterization of ultrahigh trans- sources and electronics for video signal process- parency fluoride glasses and...operates a video system through this port if desired. The optical bench in consisting of visible and infrared television cam- the trailer holds a high...resolution Fourier eras, a high-quality video cassette recorder and transform spectrometer to use in the receiving display, and a digitizer to convert
Integration of Video-Based Demonstrations to Prepare Students for the Organic Chemistry Laboratory
NASA Astrophysics Data System (ADS)
Nadelson, Louis S.; Scaggs, Jonathan; Sheffield, Colin; McDougal, Owen M.
2015-08-01
Consistent, high-quality introductions to organic chemistry laboratory techniques effectively and efficiently support student learning in the organic chemistry laboratory. In this work, we developed and deployed a series of instructional videos to communicate core laboratory techniques and concepts. Using a quasi-experimental design, we tested the videos in five traditional laboratory experiments by integrating them with the standard pre-laboratory student preparation presentations and instructor demonstrations. We assessed the influence of the videos on student laboratory knowledge and performance, using sections of students who did not view the videos as the control. Our analysis of pre-quizzes revealed the control group had equivalent scores to the treatment group, while the post-quiz results show consistently greater learning gains for the treatment group. Additionally, the students who watched the videos as part of their pre-laboratory instruction completed their experiments in less time.
A time-varying subjective quality model for mobile streaming videos with stalling events
NASA Astrophysics Data System (ADS)
Ghadiyaram, Deepti; Pan, Janice; Bovik, Alan C.
2015-09-01
Over-the-top mobile video streaming is invariably influenced by volatile network conditions which cause playback interruptions (stalling events), thereby impairing users' quality of experience (QoE). Developing models that can accurately predict users' QoE could enable the more efficient design of quality-control protocols for video streaming networks that reduce network operational costs while still delivering high-quality video content to the customers. Existing objective models that predict QoE are based on global video features, such as the number of stall events and their lengths, and are trained and validated on a small pool of ad hoc video datasets, most of which are not publicly available. The model we propose in this work goes beyond previous models as it also accounts for the fundamental effect that a viewer's recent level of satisfaction or dissatisfaction has on their overall viewing experience. In other words, the proposed model accounts for and adapts to the recency, or hysteresis effect caused by a stall event in addition to accounting for the lengths, frequency of occurrence, and the positions of stall events - factors that interact in a complex way to affect a user's QoE. On the recently introduced LIVE-Avvasi Mobile Video Database, which consists of 180 distorted videos of varied content that are afflicted solely with over 25 unique realistic stalling events, we trained and validated our model to accurately predict the QoE, attaining standout QoE prediction performance.
Integration of Video-Based Demonstrations to Prepare Students for the Organic Chemistry Laboratory
ERIC Educational Resources Information Center
Nadelson, Louis S.; Scaggs, Jonathan; Sheffield, Colin; McDougal, Owen M.
2015-01-01
Consistent, high-quality introductions to organic chemistry laboratory techniques effectively and efficiently support student learning in the organic chemistry laboratory. In this work, we developed and deployed a series of instructional videos to communicate core laboratory techniques and concepts. Using a quasi-experimental design, we tested the…
Subjective evaluation of next-generation video compression algorithms: a case study
NASA Astrophysics Data System (ADS)
De Simone, Francesca; Goldmann, Lutz; Lee, Jong-Seok; Ebrahimi, Touradj; Baroncini, Vittorio
2010-08-01
This paper describes the details and the results of the subjective quality evaluation performed at EPFL, as a contribution to the effort of the Joint Collaborative Team on Video Coding (JCT-VC) for the definition of the next-generation video coding standard. The performance of 27 coding technologies have been evaluated with respect to two H.264/MPEG-4 AVC anchors, considering high definition (HD) test material. The test campaign involved a total of 494 naive observers and took place over a period of four weeks. While similar tests have been conducted as part of the standardization process of previous video coding technologies, the test campaign described in this paper is by far the most extensive in the history of video coding standardization. The obtained subjective quality scores show high consistency and support an accurate comparison of the performance of the different coding solutions.
Action change detection in video using a bilateral spatial-temporal constraint
NASA Astrophysics Data System (ADS)
Tian, Jing; Chen, Li
2016-08-01
Action change detection in video aims to detect action discontinuity in video. The silhouettes-based features are desirable for action change detection. This paper studies the problem of silhouette-quality assessment. For that, a non-reference approach without the need for ground truth is proposed in this paper to evaluate the quality of silhouettes, by exploiting both the boundary contrast of the silhouettes in the spatial domain and the consistency of the silhouettes in the temporal domain. This is in contrast to that either only spatial information or only temporal information of silhouettes is exploited in conventional approaches. Experiments are conducted using artificially generated degraded silhouettes to show that the proposed approach outperforms conventional approaches to achieve more accurate quality assessment. Furthermore, experiments are performed to show that the proposed approach is able to improve the accuracy performance of conventional action change approaches in two human action video data-sets. The average runtime of the proposed approach for Weizmann action video data-set is 0.08 second for one frame using Matlab programming language. It is computationally efficient and potential to real-time implementations.
Rubbi, Ivan; Magnani, Daniela; Naldoni, Giada; Di Lorenzo, Rosaria; Cremonini, Valeria; Capucci, Patrizia; Artioli, Giovanna; Ferri, Paola
2016-11-22
Alzheimer's disease is the most common degenerative dementia with a predominantly senile onset. The difficult management of altered behaviour related to this disorder, poorly responsive to pharmacological treatments, has stimulated growth in non-pharmacological interventions, such as music therapy, whose effectiveness has not been supported by the literature up to now. The aim of this study was to evaluate the efficacy of video-music therapy on quality of life improvement in Patients affected by Alzheimer's Disease (AD). A pre-post study was conducted in a residential facility. 32 AD Patients, who attended this facility daily to participate in supportive and rehabilitative programs, were treated with 2 cycles of 6 video-music-therapy sessions, which consisted of folk music and video, recalling local traditions. In order to investigate their cognitive status, Mini Mental State Examination (MMSE) was administered and Patients were divided into stages according to MMSE scores. After each session of video-music-therapy, Quality of Life in Alzheimer's Disease Scale (QOL-AD) was administered to our Patients. 21 AD Patients completed the 2 cycles of video-music therapy. Among them, only the Patients with questionable, mild and moderate neurocognitive impairment (MMSE Stages 1, 2, 3) reported an improvement in their quality of life, whereas the Patients with severe deterioration (MMSE stage 4) did not report any change. Many items of QOL-AD improved, showing a statistically significantly correlation to each other. Video-music therapy was a valuable tool for improving the quality of life only in Patients affected by less severe neurocognitive impairment.
Web-video-mining-supported workflow modeling for laparoscopic surgeries.
Liu, Rui; Zhang, Xiaoli; Zhang, Hao
2016-11-01
As quality assurance is of strong concern in advanced surgeries, intelligent surgical systems are expected to have knowledge such as the knowledge of the surgical workflow model (SWM) to support their intuitive cooperation with surgeons. For generating a robust and reliable SWM, a large amount of training data is required. However, training data collected by physically recording surgery operations is often limited and data collection is time-consuming and labor-intensive, severely influencing knowledge scalability of the surgical systems. The objective of this research is to solve the knowledge scalability problem in surgical workflow modeling with a low cost and labor efficient way. A novel web-video-mining-supported surgical workflow modeling (webSWM) method is developed. A novel video quality analysis method based on topic analysis and sentiment analysis techniques is developed to select high-quality videos from abundant and noisy web videos. A statistical learning method is then used to build the workflow model based on the selected videos. To test the effectiveness of the webSWM method, 250 web videos were mined to generate a surgical workflow for the robotic cholecystectomy surgery. The generated workflow was evaluated by 4 web-retrieved videos and 4 operation-room-recorded videos, respectively. The evaluation results (video selection consistency n-index ≥0.60; surgical workflow matching degree ≥0.84) proved the effectiveness of the webSWM method in generating robust and reliable SWM knowledge by mining web videos. With the webSWM method, abundant web videos were selected and a reliable SWM was modeled in a short time with low labor cost. Satisfied performances in mining web videos and learning surgery-related knowledge show that the webSWM method is promising in scaling knowledge for intelligent surgical systems. Copyright © 2016 Elsevier B.V. All rights reserved.
Segment scheduling method for reducing 360° video streaming latency
NASA Astrophysics Data System (ADS)
Gudumasu, Srinivas; Asbun, Eduardo; He, Yong; Ye, Yan
2017-09-01
360° video is an emerging new format in the media industry enabled by the growing availability of virtual reality devices. It provides the viewer a new sense of presence and immersion. Compared to conventional rectilinear video (2D or 3D), 360° video poses a new and difficult set of engineering challenges on video processing and delivery. Enabling comfortable and immersive user experience requires very high video quality and very low latency, while the large video file size poses a challenge to delivering 360° video in a quality manner at scale. Conventionally, 360° video represented in equirectangular or other projection formats can be encoded as a single standards-compliant bitstream using existing video codecs such as H.264/AVC or H.265/HEVC. Such method usually needs very high bandwidth to provide an immersive user experience. While at the client side, much of such high bandwidth and the computational power used to decode the video are wasted because the user only watches a small portion (i.e., viewport) of the entire picture. Viewport dependent 360°video processing and delivery approaches spend more bandwidth on the viewport than on non-viewports and are therefore able to reduce the overall transmission bandwidth. This paper proposes a dual buffer segment scheduling algorithm for viewport adaptive streaming methods to reduce latency when switching between high quality viewports in 360° video streaming. The approach decouples the scheduling of viewport segments and non-viewport segments to ensure the viewport segment requested matches the latest user head orientation. A base layer buffer stores all lower quality segments, and a viewport buffer stores high quality viewport segments corresponding to the most recent viewer's head orientation. The scheduling scheme determines viewport requesting time based on the buffer status and the head orientation. This paper also discusses how to deploy the proposed scheduling design for various viewport adaptive video streaming methods. The proposed dual buffer segment scheduling method is implemented in an end-to-end tile based 360° viewports adaptive video streaming platform, where the entire 360° video is divided into a number of tiles, and each tile is independently encoded into multiple quality level representations. The client requests different quality level representations of each tile based on the viewer's head orientation and the available bandwidth, and then composes all tiles together for rendering. The simulation results verify that the proposed dual buffer segment scheduling algorithm reduces the viewport switch latency, and utilizes available bandwidth more efficiently. As a result, a more consistent immersive 360° video viewing experience can be presented to the user.
NASA Astrophysics Data System (ADS)
Strohmeier, Dominik; Kunze, Kristina; Göbel, Klemens; Liebetrau, Judith
2013-01-01
Assessing audiovisual Quality of Experience (QoE) is a key element to ensure quality acceptance of today's multimedia products. The use of descriptive evaluation methods allows evaluating QoE preferences and the underlying QoE features jointly. From our previous evaluations on QoE for mobile 3D video we found that mainly one dimension, video quality, dominates the descriptive models. Large variations of the visual video quality in the tests may be the reason for these findings. A new study was conducted to investigate whether test sets of low QoE are described differently than those of high audiovisual QoE. Reanalysis of previous data sets seems to confirm this hypothesis. Our new study consists of a pre-test and a main test, using the Descriptive Sorted Napping method. Data sets of good-only and bad-only video quality were evaluated separately. The results show that the perception of bad QoE is mainly determined one-dimensionally by visual artifacts, whereas the perception of good quality shows multiple dimensions. Here, mainly semantic-related features of the content and affective descriptors are used by the naïve test participants. The results show that, with increasing QoE of audiovisual systems, content semantics and users' a_ective involvement will become important for assessing QoE differences.
Empirical evaluation of H.265/HEVC-based dynamic adaptive video streaming over HTTP (HEVC-DASH)
NASA Astrophysics Data System (ADS)
Irondi, Iheanyi; Wang, Qi; Grecos, Christos
2014-05-01
Real-time HTTP streaming has gained global popularity for delivering video content over Internet. In particular, the recent MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard enables on-demand, live, and adaptive Internet streaming in response to network bandwidth fluctuations. Meanwhile, emerging is the new-generation video coding standard, H.265/HEVC (High Efficiency Video Coding) promises to reduce the bandwidth requirement by 50% at the same video quality when compared with the current H.264/AVC standard. However, little existing work has addressed the integration of the DASH and HEVC standards, let alone empirical performance evaluation of such systems. This paper presents an experimental HEVC-DASH system, which is a pull-based adaptive streaming solution that delivers HEVC-coded video content through conventional HTTP servers where the client switches to its desired quality, resolution or bitrate based on the available network bandwidth. Previous studies in DASH have focused on H.264/AVC, whereas we present an empirical evaluation of the HEVC-DASH system by implementing a real-world test bed, which consists of an Apache HTTP Server with GPAC, an MP4Client (GPAC) with open HEVC-based DASH client and a NETEM box in the middle emulating different network conditions. We investigate and analyze the performance of HEVC-DASH by exploring the impact of various network conditions such as packet loss, bandwidth and delay on video quality. Furthermore, we compare the Intra and Random Access profiles of HEVC coding with the Intra profile of H.264/AVC when the correspondingly encoded video is streamed with DASH. Finally, we explore the correlation among the quality metrics and network conditions, and empirically establish under which conditions the different codecs can provide satisfactory performance.
CUQI: cardiac ultrasound video quality index
Razaak, Manzoor; Martini, Maria G.
2016-01-01
Abstract. Medical images and videos are now increasingly part of modern telecommunication applications, including telemedicinal applications, favored by advancements in video compression and communication technologies. Medical video quality evaluation is essential for modern applications since compression and transmission processes often compromise the video quality. Several state-of-the-art video quality metrics used for quality evaluation assess the perceptual quality of the video. For a medical video, assessing quality in terms of “diagnostic” value rather than “perceptual” quality is more important. We present a diagnostic-quality–oriented video quality metric for quality evaluation of cardiac ultrasound videos. Cardiac ultrasound videos are characterized by rapid repetitive cardiac motions and distinct structural information characteristics that are explored by the proposed metric. Cardiac ultrasound video quality index, the proposed metric, is a full reference metric and uses the motion and edge information of the cardiac ultrasound video to evaluate the video quality. The metric was evaluated for its performance in approximating the quality of cardiac ultrasound videos by testing its correlation with the subjective scores of medical experts. The results of our tests showed that the metric has high correlation with medical expert opinions and in several cases outperforms the state-of-the-art video quality metrics considered in our tests. PMID:27014715
A video approach to interactive patient education.
Maller, C E; Twitty, V J; Sauve, A
1997-04-01
A quality improvement model presents the stages of designing and producing a preoperative videotape for improved patient satisfaction outcomes. PACU nurses formed an interdisciplinary team of providers and patients to update an existing preoperative sound/slide program into video. Improved patient outcomes were reflected in greater availability, accessibility, and consistency of preoperative instruction. A videotape program for home viewing was instituted to reach out to the surgical patient population served by the Albuquerque Veterans Affairs Medical Center in New Mexico. A quality improvement storyboard approach to videotape production met Joint Commission on Accreditation of Health Care Organization (JCAHO) standards for interactive patient education at a recent JCAHO survey. Preliminary evaluative data from patients supports a growing appeal of videos to patients and family members as an additional preoperative teaching strategy for adult surgical patients.
Does training with 3D videos improve decision-making in team invasion sports?
Hohmann, Tanja; Obelöer, Hilke; Schlapkohl, Nele; Raab, Markus
2016-01-01
We examined the effectiveness of video-based decision training in national youth handball teams. Extending previous research, we tested in Study 1 whether a three-dimensional (3D) video training group would outperform a two-dimensional (2D) group. In Study 2, a 3D training group was compared to a control group and a group trained with a traditional tactic board. In both studies, training duration was 6 weeks. Performance was measured in a pre- to post-retention design. The tests consisted of a decision-making task measuring quality of decisions (first and best option) and decision time (time for first and best option). The results of Study 1 showed learning effects and revealed that the 3D video group made faster first-option choices than the 2D group, but differences in the quality of options were not pronounced. The results of Study 2 revealed learning effects for both training groups compared to the control group, and faster choices in the 3D group compared to both other groups. Together, the results show that 3D video training is the most useful tool for improving choices in handball, but only in reference to decision time and not decision quality. We discuss the usefulness of a 3D video tool for training of decision-making skills outside the laboratory or gym.
The Development and Validation of the Game User Experience Satisfaction Scale (GUESS).
Phan, Mikki H; Keebler, Joseph R; Chaparro, Barbara S
2016-12-01
The aim of this study was to develop and psychometrically validate a new instrument that comprehensively measures video game satisfaction based on key factors. Playtesting is often conducted in the video game industry to help game developers build better games by providing insight into the players' attitudes and preferences. However, quality feedback is difficult to obtain from playtesting sessions without a quality gaming assessment tool. There is a need for a psychometrically validated and comprehensive gaming scale that is appropriate for playtesting and game evaluation purposes. The process of developing and validating this new scale followed current best practices of scale development and validation. As a result, a mixed-method design that consisted of item pool generation, expert review, questionnaire pilot study, exploratory factor analysis (N = 629), and confirmatory factor analysis (N = 729) was implemented. A new instrument measuring video game satisfaction, called the Game User Experience Satisfaction Scale (GUESS), with nine subscales emerged. The GUESS was demonstrated to have content validity, internal consistency, and convergent and discriminant validity. The GUESS was developed and validated based on the assessments of over 450 unique video game titles across many popular genres. Thus, it can be applied across many types of video games in the industry both as a way to assess what aspects of a game contribute to user satisfaction and as a tool to aid in debriefing users on their gaming experience. The GUESS can be administered to evaluate user satisfaction of different types of video games by a variety of users. © 2016, Human Factors and Ergonomics Society.
Remote stereoscopic video play platform for naked eyes based on the Android system
NASA Astrophysics Data System (ADS)
Jia, Changxin; Sang, Xinzhu; Liu, Jing; Cheng, Mingsheng
2014-11-01
As people's life quality have been improved significantly, the traditional 2D video technology can not meet people's urgent desire for a better video quality, which leads to the rapid development of 3D video technology. Simultaneously people want to watch 3D video in portable devices,. For achieving the above purpose, we set up a remote stereoscopic video play platform. The platform consists of a server and clients. The server is used for transmission of different formats of video and the client is responsible for receiving remote video for the next decoding and pixel restructuring. We utilize and improve Live555 as video transmission server. Live555 is a cross-platform open source project which provides solutions for streaming media such as RTSP protocol and supports transmission of multiple video formats. At the receiving end, we use our laboratory own player. The player for Android, which is with all the basic functions as the ordinary players do and able to play normal 2D video, is the basic structure for redevelopment. Also RTSP is implemented into this structure for telecommunication. In order to achieve stereoscopic display, we need to make pixel rearrangement in this player's decoding part. The decoding part is the local code which JNI interface calls so that we can extract video frames more effectively. The video formats that we process are left and right, up and down and nine grids. In the design and development, a large number of key technologies from Android application development have been employed, including a variety of wireless transmission, pixel restructuring and JNI call. By employing these key technologies, the design plan has been finally completed. After some updates and optimizations, the video player can play remote 3D video well anytime and anywhere and meet people's requirement.
Adaptive Video Streaming Using Bandwidth Estimation for 3.5G Mobile Network
NASA Astrophysics Data System (ADS)
Nam, Hyeong-Min; Park, Chun-Su; Jung, Seung-Won; Ko, Sung-Jea
Currently deployed mobile networks including High Speed Downlink Packet Access (HSDPA) offer only best-effort Quality of Service (QoS). In wireless best effort networks, the bandwidth variation is a critical problem, especially, for mobile devices with small buffers. This is because the bandwidth variation leads to packet losses caused by buffer overflow as well as picture freezing due to high transmission delay or buffer underflow. In this paper, in order to provide seamless video streaming over HSDPA, we propose an efficient real-time video streaming method that consists of the available bandwidth (AB) estimation for the HSDPA network and the transmission rate control to prevent buffer overflows/underflows. In the proposed method, the client estimates the AB and the estimated AB is fed back to the server through real-time transport control protocol (RTCP) packets. Then, the server adaptively adjusts the transmission rate according to the estimated AB and the buffer state obtained from the RTCP feedback information. Experimental results show that the proposed method achieves seamless video streaming over the HSDPA network providing higher video quality and lower transmission delay.
Performance comparison of AV1, HEVC, and JVET video codecs on 360 (spherical) video
NASA Astrophysics Data System (ADS)
Topiwala, Pankaj; Dai, Wei; Krishnan, Madhu; Abbas, Adeel; Doshi, Sandeep; Newman, David
2017-09-01
This paper compares the coding efficiency performance on 360 videos, of three software codecs: (a) AV1 video codec from the Alliance for Open Media (AOM); (b) the HEVC Reference Software HM; and (c) the JVET JEM Reference SW. Note that 360 video is especially challenging content, in that one codes full res globally, but typically looks locally (in a viewport), which magnifies errors. These are tested in two different projection formats ERP and RSP, to check consistency. Performance is tabulated for 1-pass encoding on two fronts: (1) objective performance based on end-to-end (E2E) metrics such as SPSNR-NN, and WS-PSNR, currently developed in the JVET committee; and (2) informal subjective assessment of static viewports. Constant quality encoding is performed with all the three codecs for an unbiased comparison of the core coding tools. Our general conclusion is that under constant quality coding, AV1 underperforms HEVC, which underperforms JVET. We also test with rate control, where AV1 currently underperforms the open source X265 HEVC codec. Objective and visual evidence is provided.
A video coding scheme based on joint spatiotemporal and adaptive prediction.
Jiang, Wenfei; Latecki, Longin Jan; Liu, Wenyu; Liang, Hui; Gorman, Ken
2009-05-01
We propose a video coding scheme that departs from traditional Motion Estimation/DCT frameworks and instead uses Karhunen-Loeve Transform (KLT)/Joint Spatiotemporal Prediction framework. In particular, a novel approach that performs joint spatial and temporal prediction simultaneously is introduced. It bypasses the complex H.26x interframe techniques and it is less computationally intensive. Because of the advantage of the effective joint prediction and the image-dependent color space transformation (KLT), the proposed approach is demonstrated experimentally to consistently lead to improved video quality, and in many cases to better compression rates and improved computational speed.
Video quality assesment using M-SVD
NASA Astrophysics Data System (ADS)
Tao, Peining; Eskicioglu, Ahmet M.
2007-01-01
Objective video quality measurement is a challenging problem in a variety of video processing application ranging from lossy compression to printing. An ideal video quality measure should be able to mimic the human observer. We present a new video quality measure, M-SVD, to evaluate distorted video sequences based on singular value decomposition. A computationally efficient approach is developed for full-reference (FR) video quality assessment. This measure is tested on the Video Quality Experts Group (VQEG) phase I FR-TV test data set. Our experiments show the graphical measure displays the amount of distortion as well as the distribution of error in all frames of the video sequence while the numerical measure has a good correlation with perceived video quality outperforms PSNR and other objective measures by a clear margin.
A new method for digital video documentation in surgical procedures and minimally invasive surgery.
Wurnig, P N; Hollaus, P H; Wurnig, C H; Wolf, R K; Ohtsuka, T; Pridun, N S
2003-02-01
Documentation of surgical procedures is limited to the accuracy of description, which depends on the vocabulary and the descriptive prowess of the surgeon. Even analog video recording could not solve the problem of documentation satisfactorily due to the abundance of recorded material. By capturing the video digitally, most problems are solved in the circumstances described in this article. We developed a cheap and useful digital video capturing system that consists of conventional computer components. Video images and clips can be captured intraoperatively and are immediately available. The system is a commercial personal computer specially configured for digital video capturing and is connected by wire to the video tower. Filming was done with a conventional endoscopic video camera. A total of 65 open and endoscopic procedures were documented in an orthopedic and a thoracic surgery unit. The median number of clips per surgical procedure was 6 (range, 1-17), and the median storage volume was 49 MB (range, 3-360 MB) in compressed form. The median duration of a video clip was 4 min 25 s (range, 45 s to 21 min). Median time for editing a video clip was 12 min for an advanced user (including cutting, title for the movie, and compression). The quality of the clips renders them suitable for presentations. This digital video documentation system allows easy capturing of intraoperative video sequences in high quality. All possibilities of documentation can be performed. With the use of an endoscopic video camera, no compromises with respect to sterility and surgical elbowroom are necessary. The cost is much lower than commercially available systems, and setting changes can be performed easily without trained specialists.
Update on POCIT portable optical communicators: VideoBeam and EtherBeam
NASA Astrophysics Data System (ADS)
Mecherle, G. Stephen; Holcomb, Terry L.
2000-05-01
LDSC is developing the POCITTM (Portable Optical Communication Integrated Transceiver) family of products which includes VideoBeamTM and the latest addition, EtherBeamTM. Each is a full duplex portable laser communicator: VideoBeamTM providing near-broadcast- quality analog video and stereo audio, and EtherBeamTM providing standard Ethernet connectivity. Each POCITTM transceiver consists of a 3.5-pound unit with a binocular- type form factor, which can be manually pointed, tripod- mounted or gyro-stabilized. Both units have an operational range of over two miles (clear air) with excellent jam- resistance and low probability of interception characteristics. The transmission wavelength of 1550 nm enables Class 1 eyesafe operation (ANSI, IEC). The POCITTM units are ideally suited for numerous military scenarios, surveillance/espionage, industrial precious mineral exploration, and campus video teleconferencing applications. VideoBeam will be available second quarter 2000, followed by EtherBeam in third quarter 2000.
Video Compression Study: h.265 vs h.264
NASA Technical Reports Server (NTRS)
Pryor, Jonathan
2016-01-01
H.265 video compression (also known as High Efficiency Video Encoding (HEVC)) promises to provide double the video quality at half the bandwidth, or the same quality at half the bandwidth of h.264 video compression [1]. This study uses a Tektronix PQA500 to determine the video quality gains by using h.265 encoding. This study also compares two video encoders to see how different implementations of h.264 and h.265 impact video quality at various bandwidths.
Perceptual tools for quality-aware video networks
NASA Astrophysics Data System (ADS)
Bovik, A. C.
2014-01-01
Monitoring and controlling the quality of the viewing experience of videos transmitted over increasingly congested networks (especially wireless networks) is a pressing problem owing to rapid advances in video-centric mobile communication and display devices that are straining the capacity of the network infrastructure. New developments in automatic perceptual video quality models offer tools that have the potential to be used to perceptually optimize wireless video, leading to more efficient video data delivery and better received quality. In this talk I will review key perceptual principles that are, or could be used to create effective video quality prediction models, and leading quality prediction models that utilize these principles. The goal is to be able to monitor and perceptually optimize video networks by making them "quality-aware."
POCIT portable optical communicators: VideoBeam and EtherBeam
NASA Astrophysics Data System (ADS)
Mecherle, G. Stephen; Holcomb, Terry L.
1999-12-01
LDSC is developing the POCITTM (Portable Optical Communication Integrated Transceiver) family of products which now includes VideoBeamTM and the latest addition, EtherBeamTM. Each is a full duplex portable laser communicator: VideoBeamTM providing near-broadcast- quality analog video and stereo audio, and EtherBeamTM providing standard Ethernet connectivity. Each POCITTM transceiver consists of a 3.5-pound unit with a binocular- type form factor, which can be manually pointed, tripod- mounted or gyro-stabilized. Both units have an operational range of over two miles (clear air) with excellent jam- resistance and low probability of interception characteristics. The transmission wavelength of 1550 nm enables Class I eyesafe operation (ANSI, IEC). The POCITTM units are ideally suited for numerous miliary scenarios, surveillance/espionage, industrial precious mineral exploration, and campus video teleconferencing applications.
Video conference quality assessment based on cooperative sensing of video and audio
NASA Astrophysics Data System (ADS)
Wang, Junxi; Chen, Jialin; Tian, Xin; Zhou, Cheng; Zhou, Zheng; Ye, Lu
2015-12-01
This paper presents a method to video conference quality assessment, which is based on cooperative sensing of video and audio. In this method, a proposed video quality evaluation method is used to assess the video frame quality. The video frame is divided into noise image and filtered image by the bilateral filters. It is similar to the characteristic of human visual, which could also be seen as a low-pass filtering. The audio frames are evaluated by the PEAQ algorithm. The two results are integrated to evaluate the video conference quality. A video conference database is built to test the performance of the proposed method. It could be found that the objective results correlate well with MOS. Then we can conclude that the proposed method is efficiency in assessing video conference quality.
Display device-adapted video quality-of-experience assessment
NASA Astrophysics Data System (ADS)
Rehman, Abdul; Zeng, Kai; Wang, Zhou
2015-03-01
Today's viewers consume video content from a variety of connected devices, including smart phones, tablets, notebooks, TVs, and PCs. This imposes significant challenges for managing video traffic efficiently to ensure an acceptable quality-of-experience (QoE) for the end users as the perceptual quality of video content strongly depends on the properties of the display device and the viewing conditions. State-of-the-art full-reference objective video quality assessment algorithms do not take into account the combined impact of display device properties, viewing conditions, and video resolution while performing video quality assessment. We performed a subjective study in order to understand the impact of aforementioned factors on perceptual video QoE. We also propose a full reference video QoE measure, named SSIMplus, that provides real-time prediction of the perceptual quality of a video based on human visual system behaviors, video content characteristics (such as spatial and temporal complexity, and video resolution), display device properties (such as screen size, resolution, and brightness), and viewing conditions (such as viewing distance and angle). Experimental results have shown that the proposed algorithm outperforms state-of-the-art video quality measures in terms of accuracy and speed.
Automated Production of Movies on a Cluster of Computers
NASA Technical Reports Server (NTRS)
Nail, Jasper; Le, Duong; Nail, William L.; Nail, William
2008-01-01
A method of accelerating and facilitating production of video and film motion-picture products, and software and generic designs of computer hardware to implement the method, are undergoing development. The method provides for automation of most of the tedious and repetitive tasks involved in editing and otherwise processing raw digitized imagery into final motion-picture products. The method was conceived to satisfy requirements, in industrial and scientific testing, for rapid processing of multiple streams of simultaneously captured raw video imagery into documentation in the form of edited video imagery and video derived data products for technical review and analysis. In the production of such video technical documentation, unlike in production of motion-picture products for entertainment, (1) it is often necessary to produce multiple video derived data products, (2) there are usually no second chances to repeat acquisition of raw imagery, (3) it is often desired to produce final products within minutes rather than hours, days, or months, and (4) consistency and quality, rather than aesthetics, are the primary criteria for judging the products. In the present method, the workflow has both serial and parallel aspects: processing can begin before all the raw imagery has been acquired, each video stream can be subjected to different stages of processing simultaneously on different computers that may be grouped into one or more cluster(s), and the final product may consist of multiple video streams. Results of processing on different computers are shared, so that workers can collaborate effectively.
Blind prediction of natural video quality.
Saad, Michele A; Bovik, Alan C; Charrier, Christophe
2014-03-01
We propose a blind (no reference or NR) video quality evaluation model that is nondistortion specific. The approach relies on a spatio-temporal model of video scenes in the discrete cosine transform domain, and on a model that characterizes the type of motion occurring in the scenes, to predict video quality. We use the models to define video statistics and perceptual features that are the basis of a video quality assessment (VQA) algorithm that does not require the presence of a pristine video to compare against in order to predict a perceptual quality score. The contributions of this paper are threefold. 1) We propose a spatio-temporal natural scene statistics (NSS) model for videos. 2) We propose a motion model that quantifies motion coherency in video scenes. 3) We show that the proposed NSS and motion coherency models are appropriate for quality assessment of videos, and we utilize them to design a blind VQA algorithm that correlates highly with human judgments of quality. The proposed algorithm, called video BLIINDS, is tested on the LIVE VQA database and on the EPFL-PoliMi video database and shown to perform close to the level of top performing reduced and full reference VQA algorithms.
Real-time video quality monitoring
NASA Astrophysics Data System (ADS)
Liu, Tao; Narvekar, Niranjan; Wang, Beibei; Ding, Ran; Zou, Dekun; Cash, Glenn; Bhagavathy, Sitaram; Bloom, Jeffrey
2011-12-01
The ITU-T Recommendation G.1070 is a standardized opinion model for video telephony applications that uses video bitrate, frame rate, and packet-loss rate to measure the video quality. However, this model was original designed as an offline quality planning tool. It cannot be directly used for quality monitoring since the above three input parameters are not readily available within a network or at the decoder. And there is a great room for the performance improvement of this quality metric. In this article, we present a real-time video quality monitoring solution based on this Recommendation. We first propose a scheme to efficiently estimate the three parameters from video bitstreams, so that it can be used as a real-time video quality monitoring tool. Furthermore, an enhanced algorithm based on the G.1070 model that provides more accurate quality prediction is proposed. Finally, to use this metric in real-world applications, we present an example emerging application of real-time quality measurement to the management of transmitted videos, especially those delivered to mobile devices.
Perceptual video quality assessment in H.264 video coding standard using objective modeling.
Karthikeyan, Ramasamy; Sainarayanan, Gopalakrishnan; Deepa, Subramaniam Nachimuthu
2014-01-01
Since usage of digital video is wide spread nowadays, quality considerations have become essential, and industry demand for video quality measurement is rising. This proposal provides a method of perceptual quality assessment in H.264 standard encoder using objective modeling. For this purpose, quality impairments are calculated and a model is developed to compute the perceptual video quality metric based on no reference method. Because of the shuttle difference between the original video and the encoded video the quality of the encoded picture gets degraded, this quality difference is introduced by the encoding process like Intra and Inter prediction. The proposed model takes into account of the artifacts introduced by these spatial and temporal activities in the hybrid block based coding methods and an objective modeling of these artifacts into subjective quality estimation is proposed. The proposed model calculates the objective quality metric using subjective impairments; blockiness, blur and jerkiness compared to the existing bitrate only calculation defined in the ITU G 1070 model. The accuracy of the proposed perceptual video quality metrics is compared against popular full reference objective methods as defined by VQEG.
Video quality assessment based on correlation between spatiotemporal motion energies
NASA Astrophysics Data System (ADS)
Yan, Peng; Mou, Xuanqin
2016-09-01
Video quality assessment (VQA) has been a hot research topic because of rapid increase of huge demand of video communications. From the earliest PSNR metric to advanced models that are perceptual aware, researchers have made great progress in this field by introducing properties of human vision system (HVS) into VQA model design. Among various algorithms that model the property of HVS perceiving motion, the spatiotemporal energy model has been validated to be high consistent with psychophysical experiments. In this paper, we take the spatiotemporal energy model into VQA model design by the following steps. 1) According to the pristine spatiotemporal energy model proposed by Adelson et al, we apply the linear filters, which are oriented in space-time and tuned in spatial frequency, to filter the reference and test videos respectively. The outputs of quadrature pairs of above filters are then squared and summed to give two measures of motion energy, which are named rightward and leftward energy responses, respectively. 2) Based on the pristine model, we calculate summation of the rightward and leftward energy responses as spatiotemporal features to represent perceptual quality information for videos, named total spatiotemporal motion energy maps. 3) The proposed FR-VQA model, named STME, is calculated with statistics based on the pixel-wise correlation between the total spatiotemporal motion energy maps of the reference and distorted videos. The STME model was validated on the LIVE VQA Database by comparing with existing FR-VQA models. Experimental results show that STME performs with excellent prediction accuracy and stays in state-of-the-art VQA models.
Robust Video Stabilization Using Particle Keypoint Update and l1-Optimized Camera Path
Jeon, Semi; Yoon, Inhye; Jang, Jinbeum; Yang, Seungji; Kim, Jisung; Paik, Joonki
2017-01-01
Acquisition of stabilized video is an important issue for various type of digital cameras. This paper presents an adaptive camera path estimation method using robust feature detection to remove shaky artifacts in a video. The proposed algorithm consists of three steps: (i) robust feature detection using particle keypoints between adjacent frames; (ii) camera path estimation and smoothing; and (iii) rendering to reconstruct a stabilized video. As a result, the proposed algorithm can estimate the optimal homography by redefining important feature points in the flat region using particle keypoints. In addition, stabilized frames with less holes can be generated from the optimal, adaptive camera path that minimizes a temporal total variation (TV). The proposed video stabilization method is suitable for enhancing the visual quality for various portable cameras and can be applied to robot vision, driving assistant systems, and visual surveillance systems. PMID:28208622
Video quality pooling adaptive to perceptual distortion severity.
Park, Jincheol; Seshadrinathan, Kalpana; Lee, Sanghoon; Bovik, Alan Conrad
2013-02-01
It is generally recognized that severe video distortions that are transient in space and/or time have a large effect on overall perceived video quality. In order to understand this phenomena, we study the distribution of spatio-temporally local quality scores obtained from several video quality assessment (VQA) algorithms on videos suffering from compression and lossy transmission over communication channels. We propose a content adaptive spatial and temporal pooling strategy based on the observed distribution. Our method adaptively emphasizes "worst" scores along both the spatial and temporal dimensions of a video sequence and also considers the perceptual effect of large-area cohesive motion flow such as egomotion. We demonstrate the efficacy of the method by testing it using three different VQA algorithms on the LIVE Video Quality database and the EPFL-PoliMI video quality database.
CVD2014-A Database for Evaluating No-Reference Video Quality Assessment Algorithms.
Nuutinen, Mikko; Virtanen, Toni; Vaahteranoksa, Mikko; Vuori, Tero; Oittinen, Pirkko; Hakkinen, Jukka
2016-07-01
In this paper, we present a new video database: CVD2014-Camera Video Database. In contrast to previous video databases, this database uses real cameras rather than introducing distortions via post-processing, which results in a complex distortion space in regard to the video acquisition process. CVD2014 contains a total of 234 videos that are recorded using 78 different cameras. Moreover, this database contains the observer-specific quality evaluation scores rather than only providing mean opinion scores. We have also collected open-ended quality descriptions that are provided by the observers. These descriptions were used to define the quality dimensions for the videos in CVD2014. The dimensions included sharpness, graininess, color balance, darkness, and jerkiness. At the end of this paper, a performance study of image and video quality algorithms for predicting the subjective video quality is reported. For this performance study, we proposed a new performance measure that accounts for observer variance. The performance study revealed that there is room for improvement regarding the video quality assessment algorithms. The CVD2014 video database has been made publicly available for the research community. All video sequences and corresponding subjective ratings can be obtained from the CVD2014 project page (http://www.helsinki.fi/psychology/groups/visualcognition/).
YouTube as a Potential Training Resource for Laparoscopic Fundoplication.
Frongia, Giovanni; Mehrabi, Arianeb; Fonouni, Hamidreza; Rennert, Helga; Golriz, Mohammad; Günther, Patrick
To analyze the surgical proficiency and educational quality of YouTube videos demonstrating laparoscopic fundoplication (LF). In this cross-sectional study, a search was performed on YouTube for videos demonstrating the LF procedure. The surgical and educational proficiency was evaluated using the objective component rating scale, the educational quality rating score, and total video quality score. Statistical significance was determined by analysis of variance, receiver operating characteristic curve, and odds ratio analysis. A total of 71 videos were included in the study; 28 (39.4%) videos were evaluated as good, 23 (32.4%) were moderate, and 20 (28.2%) were poor. Good-rated videos were significantly longer (good, 22.0 ± 5.2min; moderate, 7.8 ± 0.9min; poor, 8.5 ± 1.0min; p = 0.007) and video duration was predictive of good quality (AUC, 0.672 ± 0.067; 95% CI: 0.541-0.802; p = 0.015). For good quality, the cut-off video duration was 7:42 minute. This cut-off value had a sensitivity of 67.9%, a specificity of 60.5%, and an odds ratio of 3.23 (95% CI: 1.19-8.79; p = 0.022) in predicting good quality. Videos uploaded from industrial sources and with a higher views/days online ratio had a higher objective component rating scale and total video quality score. In contrast, the likes/dislikes ratio was not predictive of video quality. Many videos showing the LF procedure have been uploaded to YouTube with varying degrees of quality. A process for filtering LF videos with high surgical and educational quality is feasible by evaluating the video duration, uploading source, and the views/days online ratio. However, alternative videos platforms aimed at professionals should also be considered for educational purposes. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
YouTube as a potential training method for laparoscopic cholecystectomy.
Lee, Jun Suh; Seo, Ho Seok; Hong, Tae Ho
2015-08-01
The purpose of this study was to analyze the educational quality of laparoscopic cholecystectomy (LC) videos accessible on YouTube, one of the most important sources of internet-based medical information. The keyword 'laparoscopic cholecystectomy' was used to search on YouTube and the first 100 videos were analyzed. Among them, 27 videos were excluded and 73 videos were included in the study. An arbitrary score system for video quality, devised from existing LC guidelines, were used to evaluate the quality of the videos. Video demographics were analyzed by the quality and source of the video. Correlation analysis was performed. When analyzed by video quality, 11 (15.1%) were evaluated as 'good', 40 (54.8%) were 'moderate', and 22 (30.1%) were 'poor', and there were no differences in length, views per day, or number of likes, dislikes, and comments. When analyzed by source, 27 (37.0%) were uploaded by primary centers, 20 (27.4%) by secondary centers, 15 (20.5%) by tertiary centers, 5 (6.8%) by academic institutions, and 6 (8.2%) by commercial institutions. The mean score of the tertiary center group (6.0 ± 2.0) was significantly higher than the secondary center group (3.9 ± 1.4, P = 0.001). The video score had no correlation with views per day or number of likes. Many LC videos are accessible on YouTube with varying quality. Videos uploaded by tertiary centers showed the highest educational value. This discrepancy in video quality was not recognized by viewers. More videos with higher quality need to be uploaded, and an active filtering process is necessary.
Research on quality metrics of wireless adaptive video streaming
NASA Astrophysics Data System (ADS)
Li, Xuefei
2018-04-01
With the development of wireless networks and intelligent terminals, video traffic has increased dramatically. Adaptive video streaming has become one of the most promising video transmission technologies. For this type of service, a good QoS (Quality of Service) of wireless network does not always guarantee that all customers have good experience. Thus, new quality metrics have been widely studies recently. Taking this into account, the objective of this paper is to investigate the quality metrics of wireless adaptive video streaming. In this paper, a wireless video streaming simulation platform with DASH mechanism and multi-rate video generator is established. Based on this platform, PSNR model, SSIM model and Quality Level model are implemented. Quality Level Model considers the QoE (Quality of Experience) factors such as image quality, stalling and switching frequency while PSNR Model and SSIM Model mainly consider the quality of the video. To evaluate the performance of these QoE models, three performance metrics (SROCC, PLCC and RMSE) which are used to make a comparison of subjective and predicted MOS (Mean Opinion Score) are calculated. From these performance metrics, the monotonicity, linearity and accuracy of these quality metrics can be observed.
YouTube as a potential training method for laparoscopic cholecystectomy
Lee, Jun Suh; Seo, Ho Seok
2015-01-01
Purpose The purpose of this study was to analyze the educational quality of laparoscopic cholecystectomy (LC) videos accessible on YouTube, one of the most important sources of internet-based medical information. Methods The keyword 'laparoscopic cholecystectomy' was used to search on YouTube and the first 100 videos were analyzed. Among them, 27 videos were excluded and 73 videos were included in the study. An arbitrary score system for video quality, devised from existing LC guidelines, were used to evaluate the quality of the videos. Video demographics were analyzed by the quality and source of the video. Correlation analysis was performed. Results When analyzed by video quality, 11 (15.1%) were evaluated as 'good', 40 (54.8%) were 'moderate', and 22 (30.1%) were 'poor', and there were no differences in length, views per day, or number of likes, dislikes, and comments. When analyzed by source, 27 (37.0%) were uploaded by primary centers, 20 (27.4%) by secondary centers, 15 (20.5%) by tertiary centers, 5 (6.8%) by academic institutions, and 6 (8.2%) by commercial institutions. The mean score of the tertiary center group (6.0 ± 2.0) was significantly higher than the secondary center group (3.9 ± 1.4, P = 0.001). The video score had no correlation with views per day or number of likes. Conclusion Many LC videos are accessible on YouTube with varying quality. Videos uploaded by tertiary centers showed the highest educational value. This discrepancy in video quality was not recognized by viewers. More videos with higher quality need to be uploaded, and an active filtering process is necessary. PMID:26236699
Beyond the spatial paradigm: time and cinematic form in holographic art
NASA Astrophysics Data System (ADS)
Kac, Eduardo
1998-02-01
The author discusses holographic art from the point of view of the temporal properties of the medium, using examples from some of the artists who have consistently worked with film, video, digital imaging and holographic animation proper. He suggests that any consideration of this new art form must take into account its dynamic, and not only spatial, qualities. The paper is also complemented with a survey of recent and current research towards holographic film and video, evoking the unique creative potential of these emergent technologies.
Audiovisual quality evaluation of low-bitrate video
NASA Astrophysics Data System (ADS)
Winkler, Stefan; Faller, Christof
2005-03-01
Audiovisual quality assessment is a relatively unexplored topic. We designed subjective experiments for audio, video, and audiovisual quality using content and encoding parameters representative of video for mobile applications. Our focus were the MPEG-4 AVC (a.k.a. H.264) and AAC coding standards. Our goals in this study are two-fold: we want to understand the interactions between audio and video in terms of perceived audiovisual quality, and we use the subjective data to evaluate the prediction performance of our non-reference video and audio quality metrics.
Objectification of perceptual image quality for mobile video
NASA Astrophysics Data System (ADS)
Lee, Seon-Oh; Sim, Dong-Gyu
2011-06-01
This paper presents an objective video quality evaluation method for quantifying the subjective quality of digital mobile video. The proposed method aims to objectify the subjective quality by extracting edgeness and blockiness parameters. To evaluate the performance of the proposed algorithms, we carried out subjective video quality tests with the double-stimulus continuous quality scale method and obtained differential mean opinion score values for 120 mobile video clips. We then compared the performance of the proposed methods with that of existing methods in terms of the differential mean opinion score with 120 mobile video clips. Experimental results showed that the proposed methods were approximately 10% better than the edge peak signal-to-noise ratio of the J.247 method in terms of the Pearson correlation.
Effect of tape recording on perturbation measures.
Jiang, J; Lin, E; Hanson, D G
1998-10-01
Tape recorders have been shown to affect measures of voice perturbation. Few studies, however, have been conducted to quantitatively justify the use or exclusion of certain types of recorders in voice perturbation studies. This study used sinusoidal and triangular waves and synthesized vowels to compare perturbation measures extracted from directly digitized signals with those recorded and played back through various tape recorders, including 3 models of digital audio tape recorders, 2 models of analog audio cassette tape recorders, and 2 models of video tape recorders. Signal contamination for frequency perturbation values was found to be consistently minimal with digital recorders (percent jitter = 0.01%-0.02%), mildly increased with video recorders (0.05%-0.10%), moderately increased with a high-quality analog audio cassette tape recorder (0.15%), and most prominent with a low-quality analog audio cassette tape recorder (0.24%). Recorder effect on amplitude perturbation measures was lowest in digital recorders (percent shimmer = 0.09%-0.20%), mildly to moderately increased in video recorders and a high-quality analog audio cassette tape recorder (0.25%-0.45%), and most prominent in a low-quality analog audio cassette tape recorder (0.98%). The effect of cassette tape material, length of spooled tape, and duration of analysis were also tested and are discussed.
Quality and noise measurements in mobile phone video capture
NASA Astrophysics Data System (ADS)
Petrescu, Doina; Pincenti, John
2011-02-01
The quality of videos captured with mobile phones has become increasingly important particularly since resolutions and formats have reached a level that rivals the capabilities available in the digital camcorder market, and since many mobile phones now allow direct playback on large HDTVs. The video quality is determined by the combined quality of the individual parts of the imaging system including the image sensor, the digital color processing, and the video compression, each of which has been studied independently. In this work, we study the combined effect of these elements on the overall video quality. We do this by evaluating the capture under various lighting, color processing, and video compression conditions. First, we measure full reference quality metrics between encoder input and the reconstructed sequence, where the encoder input changes with light and color processing modifications. Second, we introduce a system model which includes all elements that affect video quality, including a low light additive noise model, ISP color processing, as well as the video encoder. Our experiments show that in low light conditions and for certain choices of color processing the system level visual quality may not improve when the encoder becomes more capable or the compression ratio is reduced.
Towards a Visual Quality Metric for Digital Video
NASA Technical Reports Server (NTRS)
Watson, Andrew B.
1998-01-01
The advent of widespread distribution of digital video creates a need for automated methods for evaluating visual quality of digital video. This is particularly so since most digital video is compressed using lossy methods, which involve the controlled introduction of potentially visible artifacts. Compounding the problem is the bursty nature of digital video, which requires adaptive bit allocation based on visual quality metrics. In previous work, we have developed visual quality metrics for evaluating, controlling, and optimizing the quality of compressed still images. These metrics incorporate simplified models of human visual sensitivity to spatial and chromatic visual signals. The challenge of video quality metrics is to extend these simplified models to temporal signals as well. In this presentation I will discuss a number of the issues that must be resolved in the design of effective video quality metrics. Among these are spatial, temporal, and chromatic sensitivity and their interactions, visual masking, and implementation complexity. I will also touch on the question of how to evaluate the performance of these metrics.
Automated Assessment of Visual Quality of Digital Video
NASA Technical Reports Server (NTRS)
Watson, Andrew B.; Ellis, Stephen R. (Technical Monitor)
1997-01-01
The advent of widespread distribution of digital video creates a need for automated methods for evaluating visual quality of digital video. This is particularly so since most digital video is compressed using lossy methods, which involve the controlled introduction of potentially visible artifacts. Compounding the problem is the bursty nature of digital video, which requires adaptive bit allocation based on visual quality metrics. In previous work, we have developed visual quality metrics for evaluating, controlling, and optimizing the quality of compressed still images[1-4]. These metrics incorporate simplified models of human visual sensitivity to spatial and chromatic visual signals. The challenge of video quality metrics is to extend these simplified models to temporal signals as well. In this presentation I will discuss a number of the issues that must be resolved in the design of effective video quality metrics. Among these are spatial, temporal, and chromatic sensitivity and their interactions, visual masking, and implementation complexity. I will also touch on the question of how to evaluate the performance of these metrics.
High Speed Video Applications In The Pharmaceutical Industry
NASA Astrophysics Data System (ADS)
Stapley, David
1985-02-01
The pursuit of quality is essential in the development and production of drugs. The pursuit of excellence is relentless, a never ending search. In the pharmaceutical industry, we all know and apply wide-ranging techniques to assure quality production. We all know that in reality none of these techniques are perfect for all situations. We have all experienced, the damaged foil, blister or tube, the missing leaflet, the 'hard to read' batch code. We are all aware of the need to supplement the traditional techniques of fault finding. This paper shows how high speed video systems can be applied to fully automated filling and packaging operations as a tool to aid the company's drive for high quality and productivity. The range of products involved totals some 350 in approximately 3,000 pack variants, encompassing creams, ointments, lotions, capsules, tablets, parenteral and sterile antibiotics. Pharmaceutical production demands diligence at all stages, with optimum use of the techniques offered by the latest technology. Figure 1 shows typical stages of pharmaceutical production in which quality must be assured, and highlights those stages where the use of high speed video systems have proved of value to date. The use of high speed video systems begins with the very first use of machine and materials: commissioning and validation, (the term used for determining that a process is capable of consistently producing the requisite quality) and continues to support inprocess monitoring, throughout the life of the plant. The activity of validation in the packaging environment is particularly in need of a tool to see the nature of high speed faults, no matter how infrequently they occur, so that informed changes can be made precisely and rapidly. The prime use of this tool is to ensure that machines are less sensitive to minor variations in component characteristics.
Tolu, Sena; Yurdakul, Ozan Volkan; Basaran, Betul; Rezvani, Aylin
2018-05-14
The aim of this study was to evaluate the reliability, content, and quality of videos for patients available on YouTube for learning how to self-administer subcutaneous anti-tumour necrosis factor (TNF) injections. We searched for the terms Humira injection, Enbrel injection, Simponi injection, and Cimzia injection. Videos were categorised as useful information, misleading information, useful patient opinion, and misleading patient opinion by two physicians. Videos were rated for quality on a 5-point global quality scale (GQS; 1 = poor quality, 5 = excellent quality) and reliability and content using the 5-point DISCERN scale (higher scores represent greater reliability and more comprehensive videos). Of the 142 English videos, 24 (16.9%) videos were classified as useful information, 6 (4.2%) as misleading information, 47 (33.1%) as useful patient opinion, and 65 (45.8%) as misleading patient opinion. Useful videos were the most comprehensive and had the highest reliability and quality scores. The useful information and useful patient opinion videos had the highest numbers of views per day (median 8.32, IQR: 3.40-14.28 and 5.46, IQR: 3.06-14.44), as compared with 2.32, IQR: 1.63-6.26 for misleading information videos and 2.15, IQR: 1.17-7.43 for misleading patient opinion videos (p = 0.001). Almost all (91.5%) misleading videos were uploaded by individual users. There are a substantial number of English-language YouTube videos, with high quality, and rich content and reliability that can be sources of information on proper technique of anti-TNF self-injections. Physicians should direct patients to the reliable resources of information and educate them in online resource assessment, thereby improving treatment outcomes.
Strategies of performance self-monitoring in automotive production.
Faye, Hélène; Falzon, Pierre
2009-09-01
Production in the automotive industry, based on assembly line work, is now characterized by lean manufacturing and customization. This results in greater flexibility and increased quality demands, including worker performance self-monitoring. The objectives of this study are to refine the concept of performance self-monitoring and to characterize the strategies developed by operators to achieve it. Data were collected based on the method of individual auto-confrontation, consisting of two steps: eleven assembly-line operators of a French automotive company were individually observed and video-taped while they were working; an interview then allowed each operator to discuss his/her activity based on the video-tape. This study expands the concept of performance self-monitoring by highlighting three types of strategies directly oriented toward quality: prevention, feedback control and control action strategies.
Ho, Matthew; Stothers, Lynn; Lazare, Darren; Tsang, Brian; Macnab, Andrew
2015-01-01
Many patients conduct internet searches to manage their own health problems, to decide if they need professional help, and to corroborate information given in a clinical encounter. Good information can improve patients' understanding of their condition and their self-efficacy. Patients with spinal cord injury (SCI) featuring neurogenic bladder (NB) require knowledge and skills related to their condition and need for intermittent catheterization (IC). Information quality was evaluated in videos accessed via YouTube relating to NB and IC using search terms "neurogenic bladder intermittent catheter" and "spinal cord injury intermittent catheter." Video content was independently rated by 3 investigators using criteria based on European Urological Association (EAU) guidelines and established clinical practice. In total, 71 videos met the inclusion criteria. Of these, 12 (17%) addressed IC and 50 (70%) contained information on NB. The remaining videos met inclusion criteria, but did not contain information relevant to either IC or NB. Analysis indicated poor overall quality of information, with some videos with information contradictory to EAU guidelines for IC. High-quality videos were randomly distributed by YouTube. IC videos featuring a healthcare narrator scored significantly higher than patient-narrated videos, but not higher than videos with a merchant narrator. About half of the videos contained commercial content. Some good-quality educational videos about NB and IC are available on YouTube, but most are poor. The videos deemed good quality were not prominently ranked by the YouTube search algorithm, consequently user access is less likely. Study limitations include the limit of 50 videos per category and the use of a de novo rating tool. Information quality in videos with healthcare narrators was not higher than in those featuring merchant narrators. Better material is required to improve patients' understanding of their condition.
No-reference video quality measurement: added value of machine learning
NASA Astrophysics Data System (ADS)
Mocanu, Decebal Constantin; Pokhrel, Jeevan; Garella, Juan Pablo; Seppänen, Janne; Liotou, Eirini; Narwaria, Manish
2015-11-01
Video quality measurement is an important component in the end-to-end video delivery chain. Video quality is, however, subjective, and thus, there will always be interobserver differences in the subjective opinion about the visual quality of the same video. Despite this, most existing works on objective quality measurement typically focus only on predicting a single score and evaluate their prediction accuracies based on how close it is to the mean opinion scores (or similar average based ratings). Clearly, such an approach ignores the underlying diversities in the subjective scoring process and, as a result, does not allow further analysis on how reliable the objective prediction is in terms of subjective variability. Consequently, the aim of this paper is to analyze this issue and present a machine-learning based solution to address it. We demonstrate the utility of our ideas by considering the practical scenario of video broadcast transmissions with focus on digital terrestrial television (DTT) and proposing a no-reference objective video quality estimator for such application. We conducted meaningful verification studies on different video content (including video clips recorded from real DTT broadcast transmissions) in order to verify the performance of the proposed solution.
'How to stop a nosebleed': an assessment of the quality of epistaxis treatment advice on YouTube.
Haymes, A T; Harries, V
2016-08-01
Video hosting websites are increasingly being used to disseminate health education messages. This study aimed to assess the quality of advice contained within YouTube videos on the conservative management of epistaxis. YouTube.com was searched using the phrase 'how to stop a nosebleed'. The first 50 videos were screened. Objective advice scores and subjective production quality scores were attributed by independent raters. Forty-five videos were analysed. The mean advice score was 2.0 out of 8 and the mean production quality score was 1.6 out of 3. There were no correlations between a video's advice score and its search results rank (ρ = -0.28, p = 0.068), its view count (ρ = 0.20, p = 0.19) or its number of 'likes' (ρ = 0.21, p = 0.18). The quality of information on conservative epistaxis management within YouTube videos is extremely variable. A high search rank is no indication of video quality. Many videos proffer inappropriate and dangerous 'alternative' advice. We do not recommend YouTube as a source for patient information.
NASA Astrophysics Data System (ADS)
Sevcik, L.; Uhrin, D.; Frnda, J.; Voznak, M.; Toral-Cruz, Homer; Mikulec, M.; Jakovlev, Sergej
2015-05-01
Nowadays, the interest in real-time services, like audio and video, is growing. These services are mostly transmitted over packet networks, which are based on IP protocol. It leads to analyses of these services and their behavior in such networks which are becoming more frequent. Video has become the significant part of all data traffic sent via IP networks. In general, a video service is one-way service (except e.g. video calls) and network delay is not such an important factor as in a voice service. Dominant network factors that influence the final video quality are especially packet loss, delay variation and the capacity of the transmission links. Analysis of video quality concentrates on the resistance of video codecs to packet loss in the network, which causes artefacts in the video. IPsec provides confidentiality in terms of safety, integrity and non-repudiation (using HMAC-SHA1 and 3DES encryption for confidentiality and AES in CBC mode) with an authentication header and ESP (Encapsulating Security Payload). The paper brings a detailed view of the performance of video streaming over an IP-based network. We compared quality of video with packet loss and encryption as well. The measured results demonstrated the relation between the video codec type and bitrate to the final video quality.
NASA Astrophysics Data System (ADS)
Pei, Yong; Modestino, James W.
2007-12-01
We describe a multilayered video transport scheme for wireless channels capable of adapting to channel conditions in order to maximize end-to-end quality of service (QoS). This scheme combines a scalable H.263+ video source coder with unequal error protection (UEP) across layers. The UEP is achieved by employing different channel codes together with a multiresolution modulation approach to transport the different priority layers. Adaptivity to channel conditions is provided through a joint source-channel coding (JSCC) approach which attempts to jointly optimize the source and channel coding rates together with the modulation parameters to obtain the maximum achievable end-to-end QoS for the prevailing channel conditions. In this work, we model the wireless links as slow-fading Rician channel where the channel conditions can be described in terms of the channel signal-to-noise ratio (SNR) and the ratio of specular-to-diffuse energy[InlineEquation not available: see fulltext.]. The multiresolution modulation/coding scheme consists of binary rate-compatible punctured convolutional (RCPC) codes used together with nonuniform phase-shift keyed (PSK) signaling constellations. Results indicate that this adaptive JSCC scheme employing scalable video encoding together with a multiresolution modulation/coding approach leads to significant improvements in delivered video quality for specified channel conditions. In particular, the approach results in considerably improved graceful degradation properties for decreasing channel SNR.
YouTube provides irrelevant information for the diagnosis and treatment of hip arthritis.
Koller, Ulrich; Waldstein, Wenzel; Schatz, Klaus-Dieter; Windhager, Reinhard
2016-10-01
YouTube is increasingly becoming a key source for people to satisfy the need for additional information concerning their medical condition. This study analyses the completeness of accurate information found on YouTube pertaining to hip arthritis. The present study analyzed 133 YouTube videos using the search terms: hip arthritis, hip arthritis symptoms, hip arthritis diagnosis, hip arthritis treatment and hip replacement. Two quality assessment checklists with a scale of 0 to 12 points were developed to evaluate available video content for the diagnosis and the treatment of hip arthritis. Videos were grouped into poor quality (grade 0-3), moderate quality (grade 4-7) and excellent quality (grade 8-12), respectively. Three independent observers assessed all videos using the new grading system and independently scored all videos. Discrepancies regarding the categories were clarified by consensus discussion. For intra-observer reliabilities, grading was performed at two occasions separated by four weeks. Eighty-four percent (n = 112) had a poor diagnostic information quality, 14% (n = 19) a moderate quality and only 2% (n = 2) an excellent quality, respectively. In 86% (n = 114), videos provided poor treatment information quality. Eleven percent (n = 15) of videos had a moderate quality and only 3% (n = 4) an excellent quality, respectively. The present study demonstrates that YouTube is a poor source for accurate information pertaining to the diagnosis and treatment of hip arthritis. These finding are of high relevance for clinicians as videos are going to become the primary source of information for patients. Therefore, high quality educational videos are needed to further guide patients on the way from the diagnosis of hip arthritis to its proper treatment.
No-reference quality assessment based on visual perception
NASA Astrophysics Data System (ADS)
Li, Junshan; Yang, Yawei; Hu, Shuangyan; Zhang, Jiao
2014-11-01
The visual quality assessment of images/videos is an ongoing hot research topic, which has become more and more important for numerous image and video processing applications with the rapid development of digital imaging and communication technologies. The goal of image quality assessment (IQA) algorithms is to automatically assess the quality of images/videos in agreement with human quality judgments. Up to now, two kinds of models have been used for IQA, namely full-reference (FR) and no-reference (NR) models. For FR models, IQA algorithms interpret image quality as fidelity or similarity with a perfect image in some perceptual space. However, the reference image is not available in many practical applications, and a NR IQA approach is desired. Considering natural vision as optimized by the millions of years of evolutionary pressure, many methods attempt to achieve consistency in quality prediction by modeling salient physiological and psychological features of the human visual system (HVS). To reach this goal, researchers try to simulate HVS with image sparsity coding and supervised machine learning, which are two main features of HVS. A typical HVS captures the scenes by sparsity coding, and uses experienced knowledge to apperceive objects. In this paper, we propose a novel IQA approach based on visual perception. Firstly, a standard model of HVS is studied and analyzed, and the sparse representation of image is accomplished with the model; and then, the mapping correlation between sparse codes and subjective quality scores is trained with the regression technique of least squaresupport vector machine (LS-SVM), which gains the regressor that can predict the image quality; the visual metric of image is predicted with the trained regressor at last. We validate the performance of proposed approach on Laboratory for Image and Video Engineering (LIVE) database, the specific contents of the type of distortions present in the database are: 227 images of JPEG2000, 233 images of JPEG, 174 images of White Noise, 174 images of Gaussian Blur, 174 images of Fast Fading. The database includes subjective differential mean opinion score (DMOS) for each image. The experimental results show that the proposed approach not only can assess many kinds of distorted images quality, but also exhibits a superior accuracy and monotonicity.
Developing High-Quality Assessments that Align with Instructional Video Games. CRESST Report 774
ERIC Educational Resources Information Center
Vendlinski, Terry P.; Delacruz, Girlie C.; Buschang, Rebecca E.; Chung, Gregory K. W. K.; Baker, Eva L.
2010-01-01
The evaluation of educational interventions requires assessments that consistently (reliably) produce data from which accurate (valid) inferences about the test subjects can be made for some stated purpose. Despite codified definitions of all these terms, there remains vibrant debate about the assessment design process and how measures of…
Energy Efficient Image/Video Data Transmission on Commercial Multi-Core Processors
Lee, Sungju; Kim, Heegon; Chung, Yongwha; Park, Daihee
2012-01-01
In transmitting image/video data over Video Sensor Networks (VSNs), energy consumption must be minimized while maintaining high image/video quality. Although image/video compression is well known for its efficiency and usefulness in VSNs, the excessive costs associated with encoding computation and complexity still hinder its adoption for practical use. However, it is anticipated that high-performance handheld multi-core devices will be used as VSN processing nodes in the near future. In this paper, we propose a way to improve the energy efficiency of image and video compression with multi-core processors while maintaining the image/video quality. We improve the compression efficiency at the algorithmic level or derive the optimal parameters for the combination of a machine and compression based on the tradeoff between the energy consumption and the image/video quality. Based on experimental results, we confirm that the proposed approach can improve the energy efficiency of the straightforward approach by a factor of 2∼5 without compromising image/video quality. PMID:23202181
DairyBeef: maximizing quality and profits--a consistent food safety message.
Moore, D A; Kirk, J H; Klingborg, D J; Garry, F; Wailes, W; Dalton, J; Busboom, J; Sams, R W; Poe, M; Payne, M; Marchello, J; Looper, M; Falk, D; Wright, T
2004-01-01
To respond to meat safety and quality issues in dairy market cattle, a collaborative project team for 7 western states was established to develop educational resources providing a consistent meat safety and quality message to dairy producers, farm advisors, and veterinarians. The team produced an educational website and CD-ROM course that included videos, narrated slide sets, and on-farm tools. The objectives of this course were: 1) to help producers and their advisors understand market cattle food safety and quality issues, 2) help maintain markets for these cows, and 3) help producers identify ways to improve the quality of dairy cattle going to slaughter. DairyBeef. Maximizing Quality & Profits consists of 6 sections, including 4 core segments. Successful completion of quizzes following each core segment is required for participants to receive a certificate of completion. A formative evaluation of the program revealed the necessity for minor content and technological changes with the web-based course. All evaluators considered the materials relevant to dairy producers. After editing, course availability was enabled in February, 2003. Between February and May, 2003, 21 individuals received certificates of completion.
Quality Scalability Aware Watermarking for Visual Content.
Bhowmik, Deepayan; Abhayaratne, Charith
2016-11-01
Scalable coding-based content adaptation poses serious challenges to traditional watermarking algorithms, which do not consider the scalable coding structure and hence cannot guarantee correct watermark extraction in media consumption chain. In this paper, we propose a novel concept of scalable blind watermarking that ensures more robust watermark extraction at various compression ratios while not effecting the visual quality of host media. The proposed algorithm generates scalable and robust watermarked image code-stream that allows the user to constrain embedding distortion for target content adaptations. The watermarked image code-stream consists of hierarchically nested joint distortion-robustness coding atoms. The code-stream is generated by proposing a new wavelet domain blind watermarking algorithm guided by a quantization based binary tree. The code-stream can be truncated at any distortion-robustness atom to generate the watermarked image with the desired distortion-robustness requirements. A blind extractor is capable of extracting watermark data from the watermarked images. The algorithm is further extended to incorporate a bit-plane discarding-based quantization model used in scalable coding-based content adaptation, e.g., JPEG2000. This improves the robustness against quality scalability of JPEG2000 compression. The simulation results verify the feasibility of the proposed concept, its applications, and its improved robustness against quality scalable content adaptation. Our proposed algorithm also outperforms existing methods showing 35% improvement. In terms of robustness to quality scalable video content adaptation using Motion JPEG2000 and wavelet-based scalable video coding, the proposed method shows major improvement for video watermarking.
Haddock, Luis J; Kim, David Y; Mukai, Shizuo
2013-01-01
Purpose. We describe in detail a relatively simple technique of fundus photography in human and rabbit eyes using a smartphone, an inexpensive app for the smartphone, and instruments that are readily available in an ophthalmic practice. Methods. Fundus images were captured with a smartphone and a 20D lens with or without a Koeppe lens. By using the coaxial light source of the phone, this system works as an indirect ophthalmoscope that creates a digital image of the fundus. The application whose software allows for independent control of focus, exposure, and light intensity during video filming was used. With this app, we recorded high-definition videos of the fundus and subsequently extracted high-quality, still images from the video clip. Results. The described technique of smartphone fundus photography was able to capture excellent high-quality fundus images in both children under anesthesia and in awake adults. Excellent images were acquired with the 20D lens alone in the clinic, and the addition of the Koeppe lens in the operating room resulted in the best quality images. Successful photodocumentation of rabbit fundus was achieved in control and experimental eyes. Conclusion. The currently described system was able to take consistently high-quality fundus photographs in patients and in animals using readily available instruments that are portable with simple power sources. It is relatively simple to master, is relatively inexpensive, and can take advantage of the expanding mobile-telephone networks for telemedicine.
Quality versus intelligibility: studying human preferences for American Sign Language video
NASA Astrophysics Data System (ADS)
Ciaramello, Frank M.; Hemami, Sheila S.
2011-03-01
Real-time videoconferencing using cellular devices provides natural communication to the Deaf community. For this application, compressed American Sign Language (ASL) video must be evaluated in terms of the intelligibility of the conversation and not in terms of the overall aesthetic quality of the video. This work presents a paired comparison experiment to determine the subjective preferences of ASL users in terms of the trade-off between intelligibility and quality when varying the proportion of the bitrate allocated explicitly to the regions of the video containing the signer. A rate-distortion optimization technique, which jointly optimizes a quality criteria and an intelligibility criteria according to a user-specified parameter, generates test video pairs for the subjective experiment. Experimental results suggest that at sufficiently high bitrates, all users prefer videos in which the non-signer regions in the video are encoded with some nominal rate. As the total encoding bitrate decreases, users generally prefer video in which a greater proportion of the rate is allocated to the signer. The specific operating points preferred in the quality-intelligibility trade-off vary with the demographics of the users.
Shima, Yoichiro; Suwa, Akina; Gomi, Yuichiro; Nogawa, Hiroki; Nagata, Hiroshi; Tanaka, Hiroshi
2007-01-01
Real-time video pictures can be transmitted inexpensively via a broadband connection using the DVTS (digital video transport system). However, the degradation of video pictures transmitted by DVTS has not been sufficiently evaluated. We examined the application of DVTS to remote consultation by using images of laparoscopic and endoscopic surgeries. A subjective assessment by the double stimulus continuous quality scale (DSCQS) method of the transmitted video pictures was carried out by eight doctors. Three of the four video recordings were assessed as being transmitted with no degradation in quality. None of the doctors noticed any degradation in the images due to encryption by the VPN (virtual private network) system. We also used an automatic picture quality assessment system to make an objective assessment of the same images. The objective DSCQS values were similar to the subjective ones. We conclude that although the quality of video pictures transmitted by the DVTS was slightly reduced, they were useful for clinical purposes. Encryption with a VPN did not degrade image quality.
Ho, Matthew; Stothers, Lynn; Lazare, Darren; Tsang, Brian; Macnab, Andrew
2015-01-01
Introduction: Many patients conduct internet searches to manage their own health problems, to decide if they need professional help, and to corroborate information given in a clinical encounter. Good information can improve patients’ understanding of their condition and their self-efficacy. Patients with spinal cord injury (SCI) featuring neurogenic bladder (NB) require knowledge and skills related to their condition and need for intermittent catheterization (IC). Methods: Information quality was evaluated in videos accessed via YouTube relating to NB and IC using search terms “neurogenic bladder intermittent catheter” and “spinal cord injury intermittent catheter.” Video content was independently rated by 3 investigators using criteria based on European Urological Association (EAU) guidelines and established clinical practice. Results: In total, 71 videos met the inclusion criteria. Of these, 12 (17%) addressed IC and 50 (70%) contained information on NB. The remaining videos met inclusion criteria, but did not contain information relevant to either IC or NB. Analysis indicated poor overall quality of information, with some videos with information contradictory to EAU guidelines for IC. High-quality videos were randomly distributed by YouTube. IC videos featuring a healthcare narrator scored significantly higher than patient-narrated videos, but not higher than videos with a merchant narrator. About half of the videos contained commercial content. Conclusions: Some good-quality educational videos about NB and IC are available on YouTube, but most are poor. The videos deemed good quality were not prominently ranked by the YouTube search algorithm, consequently user access is less likely. Study limitations include the limit of 50 videos per category and the use of a de novo rating tool. Information quality in videos with healthcare narrators was not higher than in those featuring merchant narrators. Better material is required to improve patients’ understanding of their condition. PMID:26644803
A hardware-oriented concurrent TZ search algorithm for High-Efficiency Video Coding
NASA Astrophysics Data System (ADS)
Doan, Nghia; Kim, Tae Sung; Rhee, Chae Eun; Lee, Hyuk-Jae
2017-12-01
High-Efficiency Video Coding (HEVC) is the latest video coding standard, in which the compression performance is double that of its predecessor, the H.264/AVC standard, while the video quality remains unchanged. In HEVC, the test zone (TZ) search algorithm is widely used for integer motion estimation because it effectively searches the good-quality motion vector with a relatively small amount of computation. However, the complex computation structure of the TZ search algorithm makes it difficult to implement it in the hardware. This paper proposes a new integer motion estimation algorithm which is designed for hardware execution by modifying the conventional TZ search to allow parallel motion estimations of all prediction unit (PU) partitions. The algorithm consists of the three phases of zonal, raster, and refinement searches. At the beginning of each phase, the algorithm obtains the search points required by the original TZ search for all PU partitions in a coding unit (CU). Then, all redundant search points are removed prior to the estimation of the motion costs, and the best search points are then selected for all PUs. Compared to the conventional TZ search algorithm, experimental results show that the proposed algorithm significantly decreases the Bjøntegaard Delta bitrate (BD-BR) by 0.84%, and it also reduces the computational complexity by 54.54%.
Video medical interpretation over 3G cellular networks: a feasibility study.
Locatis, Craig; Williamson, Deborah; Sterrett, James; Detzler, Isabel; Ackerman, Michael
2011-12-01
To test the feasibility of using cell phone technology to provide video medical interpretation services at a distance. Alternative cell phone services were researched and videoconferencing technologies were tried out to identify video products and telecommunication services needed to meet video medical interpretation requirements. The video and telecommunication technologies were tried out in a pharmacy setting and compared with use of the telephone. Outcomes were similar to findings in previous research involving video medical interpretation with higher bandwidth and video quality. Patients appreciated the interpretation service no matter how it is provided, while health providers and interpreters preferred video. It is possible to provide video medical interpretation services via cellular communication using lower bandwidth videoconferencing technology that provides sufficient quality, at least in pharmacy settings. However, a number of issues need to be addressed to ensure quality of service.
Stellefson, Michael; Chaney, Beth; Ochipa, Kathleen; Chaney, Don; Haider, Zeerak; Hanik, Bruce; Chavarria, Enmanuel; Bernhardt, Jay M
2014-05-01
The aim of the present study is to conduct a social media content analysis of chronic obstructive pulmonary disease (COPD) patient education videos on YouTube. A systematic search protocol was used to locate 223 videos. Two independent coders evaluated each video to determine topics covered, media source(s) of posted videos, information quality as measured by HONcode guidelines for posting trustworthy health information on the Internet, and viewer exposure/engagement metrics. Over half the videos (n = 113, 50.7%) included information on medication management, with far fewer videos on smoking cessation (n = 40, 17.9%). Most videos were posted by a health agency or organization (n = 128, 57.4%), and the majority of videos were rated as high quality (n = 154, 69.1%). HONcode adherence differed by media source (Fisher's exact test = 20.52, p = 0.01), however with user-generated content receiving the lowest quality scores. Overall level of user engagement as measured by number of "likes," "favorites," "dislikes," and user comments was low (median range = 0-3, interquartile range = 0-16) across all sources of media. Study findings suggest that COPD education via YouTube has the potential to reach and inform patients; however, existing video content and quality varies significantly. Future interventions should help direct individuals with COPD to engage with high-quality patient education videos on YouTube that are posted by reputable health organizations and qualified medical professionals. Patients should be educated to avoid and/or critically view low-quality videos posted by individual YouTube users who are not health professionals.
YouTube as a source of COPD patient education: A social media content analysis
Stellefson, Michael; Chaney, Beth; Ochipa, Kathleen; Chaney, Don; Haider, Zeerak; Hanik, Bruce; Chavarria, Enmanuel; Bernhardt, Jay M.
2014-01-01
Objective Conduct a social media content analysis of COPD patient education videos on YouTube. Methods A systematic search protocol was used to locate 223 videos. Two independent coders evaluated each video to determine topics covered, media source(s) of posted videos, information quality as measured by HONcode guidelines for posting trustworthy health information on the Internet, and viewer exposure/engagement metrics. Results Over half the videos (n=113, 50.7%) included information on medication management, with far fewer videos on smoking cessation (n=40, 17.9%). Most videos were posted by a health agency or organization (n=128, 57.4%), and the majority of videos were rated as high quality (n=154, 69.1%). HONcode adherence differed by media source (Fisher’s Exact Test=20.52, p=.01), with user-generated content (UGC) receiving the lowest quality scores. Overall level of user engagement as measured by number of “likes,” “favorites,” “dislikes,” and user comments was low (mdn range = 0–3, interquartile (IQR) range = 0–16) across all sources of media. Conclusion Study findings suggest that COPD education via YouTube has the potential to reach and inform patients, however, existing video content and quality varies significantly. Future interventions should help direct individuals with COPD to increase their engagement with high-quality patient education videos on YouTube that are posted by reputable health organizations and qualified medical professionals. Patients should be educated to avoid and/or critically view low-quality videos posted by individual YouTube users who are not health professionals. PMID:24659212
Video-based teleradiology for intraosseous lesions. A receiver operating characteristic analysis.
Tyndall, D A; Boyd, K S; Matteson, S R; Dove, S B
1995-11-01
Immediate access to off-site expert diagnostic consultants regarding unusual radiographic findings or radiographic quality assurance issues could be a current problem for private dental practitioners. Teleradiology, a system for transmitting radiographic images, offers a potential solution to this problem. Although much research has been done to evaluate feasibility and utilization of teleradiology systems in medical imaging, little research on dental applications has been performed. In this investigation 47 panoramic films with an equal distribution of images with intraosseous jaw lesions and no disease were viewed by a panel of observers with teleradiology and conventional viewing methods. The teleradiology system consisted of an analog video-based system simulating remote radiographic consultation between a general dentist and a dental imaging specialist. Conventional viewing consisted of traditional viewbox methods. Observers were asked to identify the presence or absence of 24 intraosseous lesions and to determine their locations. No statistically significant differences in modalities or observers were identified between methods at the 0.05 level. The results indicate that viewing intraosseous lesions of video-based panoramic images is equal to conventional light box viewing.
The compressed average image intensity metric for stereoscopic video quality assessment
NASA Astrophysics Data System (ADS)
Wilczewski, Grzegorz
2016-09-01
The following article depicts insights towards design, creation and testing of a genuine metric designed for a 3DTV video quality evaluation. The Compressed Average Image Intensity (CAII) mechanism is based upon stereoscopic video content analysis, setting its core feature and functionality to serve as a versatile tool for an effective 3DTV service quality assessment. Being an objective type of quality metric it may be utilized as a reliable source of information about the actual performance of a given 3DTV system, under strict providers evaluation. Concerning testing and the overall performance analysis of the CAII metric, the following paper presents comprehensive study of results gathered across several testing routines among selected set of samples of stereoscopic video content. As a result, the designed method for stereoscopic video quality evaluation is investigated across the range of synthetic visual impairments injected into the original video stream.
Evaluating the Accuracy and Quality of the Information in Kyphosis Videos Shared on YouTube.
Erdem, Mehmet Nuri; Karaca, Sinan
2018-04-16
A quality-control YouTube-based study using the recognized quality scoring systems. In this study, our aim was to confirm the accuracy and quality of the information in kyphosis videos shared on YouTube. The Internet is a widely and increasingly used source for obtaining medical information both by patients and clinicians. YouTube, in particular, manifests itself as a leading source with its ease of access to information and visual advantage for Internet users. The first 50 videos returned by the YouTube search engine in response to 'kyphosis' keyword query were included in the study and categorized under seven and six groups, based on their source and content. The popularity of the videos were evaluated with a new index called the video power index (VPI). The quality, educational quality and accuracy of the source of information were measured using the JAMA score, Global Quality Score (GQS) and Kyphosis Specific Score (KSS). Videos had a mean duration of 397 seconds and a mean number of views of 131,644, with a total viewing number of 6,582,221. The source (uploader) in 36% of the videos was a trainer and the content in 46% of the videos was exercise training. 72% of the videos were about postural kyphosis. Videos had a mean JAMA score of 1.36 (range: 1 to 4), GQS of 1.68 (range: 1 to 5) and KSS of 3.02 (range:0 to 32). The academic group had the highest scores and the lowest VPIs. Online information on kyphosis is low quality and its contents are of unknown source and accuracy. In order to keep the balance in sharing the right information with the patient, clinicians should possess knowledge about the online information related to their field, and should contribute to the development of optimal medical videos. 3.
An objective method for a video quality evaluation in a 3DTV service
NASA Astrophysics Data System (ADS)
Wilczewski, Grzegorz
2015-09-01
The following article describes proposed objective method for a 3DTV video quality evaluation, a Compressed Average Image Intensity (CAII) method. Identification of the 3DTV service's content chain nodes enables to design a versatile, objective video quality metric. It is based on an advanced approach to the stereoscopic videostream analysis. Insights towards designed metric mechanisms, as well as the evaluation of performance of the designed video quality metric, in the face of the simulated environmental conditions are herein discussed. As a result, created CAII metric might be effectively used in a variety of service quality assessment applications.
The role of optical flow in automated quality assessment of full-motion video
NASA Astrophysics Data System (ADS)
Harguess, Josh; Shafer, Scott; Marez, Diego
2017-09-01
In real-world video data, such as full-motion-video (FMV) taken from unmanned vehicles, surveillance systems, and other sources, various corruptions to the raw data is inevitable. This can be due to the image acquisition process, noise, distortion, and compression artifacts, among other sources of error. However, we desire methods to analyze the quality of the video to determine whether the underlying content of the corrupted video can be analyzed by humans or machines and to what extent. Previous approaches have shown that motion estimation, or optical flow, can be an important cue in automating this video quality assessment. However, there are many different optical flow algorithms in the literature, each with their own advantages and disadvantages. We examine the effect of the choice of optical flow algorithm (including baseline and state-of-the-art), on motionbased automated video quality assessment algorithms.
Modeling the time--varying subjective quality of HTTP video streams with rate adaptations.
Chen, Chao; Choi, Lark Kwon; de Veciana, Gustavo; Caramanis, Constantine; Heath, Robert W; Bovik, Alan C
2014-05-01
Newly developed hypertext transfer protocol (HTTP)-based video streaming technologies enable flexible rate-adaptation under varying channel conditions. Accurately predicting the users' quality of experience (QoE) for rate-adaptive HTTP video streams is thus critical to achieve efficiency. An important aspect of understanding and modeling QoE is predicting the up-to-the-moment subjective quality of a video as it is played, which is difficult due to hysteresis effects and nonlinearities in human behavioral responses. This paper presents a Hammerstein-Wiener model for predicting the time-varying subjective quality (TVSQ) of rate-adaptive videos. To collect data for model parameterization and validation, a database of longer duration videos with time-varying distortions was built and the TVSQs of the videos were measured in a large-scale subjective study. The proposed method is able to reliably predict the TVSQ of rate adaptive videos. Since the Hammerstein-Wiener model has a very simple structure, the proposed method is suitable for online TVSQ prediction in HTTP-based streaming.
Angott, Andrea M.; Comerford, David A.; Ubel, Peter A.
2014-01-01
Objective To test a video intervention as a way to improve predictions of mood and quality-of-life with an emotionally evocative medical condition. Such predictions are typically inaccurate, which can be consequential for decision making. Method In Part 1, people presently or formerly living with ostomies predicted how watching a video depicting a person changing his ostomy pouch would affect mood and quality-of-life forecasts for life with an ostomy. In Part 2, participants from the general public read a description about life with an ostomy; half also watched a video depicting a person changing his ostomy pouch. Participants’ quality-of-life and mood forecasts for life with an ostomy were assessed. Results Contrary to our expectations, and the expectations of people presently or formerly living with ostomies, the video did not reduce mood or quality-of-life estimates, even among participants high in trait disgust sensitivity. Among low-disgust participants, watching the video increased quality-of-life predictions for ostomy. Conclusion Video interventions may improve mood and quality-of-life forecasts for medical conditions, including those that may elicit disgust, such as ostomy. Practice implications Video interventions focusing on patients’ experience of illness continue to show promise as components of decision aids, even for emotionally charged health states such as ostomy. PMID:23177398
STS-74/Mir photogrammetric appendage structural dynamics experiment
NASA Technical Reports Server (NTRS)
Welch, Sharon S.; Gilbert, Michael G.
1996-01-01
The Photogrammetric Appendage Structural Dynamics Experiment (PASDE) is an International Space Station (ISS) Phase-1 risk mitigation experiment. Phase-1 experiments are performed during docking missions of the U.S. Space Shuttle to the Russian Space Station Mir. The purpose of the experiment is to demonstrate the use of photogrammetric techniques for determination of structural dynamic mode parameters of solar arrays and other spacecraft appendages. Photogrammetric techniques are a low cost alternative to appendage mounted accelerometers for the ISS program. The objective of the first flight of PASDE, on STS-74 in November 1995, was to obtain video images of Mir Kvant-2 solar array response to various structural dynamic excitation events. More than 113 minutes of high quality structural response video data was collected during the mission. The PASDE experiment hardware consisted of three instruments each containing two video cameras, two video tape recorders, a modified video signal time inserter, and associated avionics boxes. The instruments were designed, fabricated, and tested at the NASA Langley Research Center in eight months. The flight hardware was integrated into standard Hitchhiker canisters at the NASA Goddard Space Flight Center and then installed into the Space Shuttle cargo bay in locations selected to achieve good video coverage and photogrammetric geometry.
Teaching professionalism to first year medical students using video clips.
Shevell, Allison Haley; Thomas, Aliki; Fuks, Abraham
2015-01-01
Medical schools are confronted with the challenge of teaching professionalism during medical training. The aim of this study was to examine medical students' perceptions of using video clips as a beneficial teaching tool to learn professionalism and other aspects of physicianship. As part of the longitudinal Physician Apprenticeship course at McGill University, first year medical students viewed video clips from the television series ER. The study used qualitative description and thematic analysis to interpret responses to questionnaires, which explored the educational merits of this exercise. Completed questionnaires were submitted by 112 students from 21 small groups. A major theme concerned the students' perceptions of the utility of video clips as a teaching tool, and consisted of comments organized into 10 categories: "authenticity and believability", "thought provoking", "skills and approaches", "setting", "medium", "level of training", "mentorship", "experiential learning", "effectiveness" and "relevance to practice". Another major theme reflected the qualities of physicianship portrayed in video clips, and included seven categories: "patient-centeredness", "communication", "physician-patient relationship", "professionalism", "ethical behavior", "interprofessional practice" and "mentorship". This study demonstrated that students perceived the value of using video clips from a television series as a means of teaching professionalism and other aspects of physicianship.
Nissan, Michael E; Gupta, Amar; Rayess, Hani; Black, Kevin Z; Carron, Michael
2018-02-01
Physicians should be aware of both websites and videos available online regarding the otoplasty procedure to provide quality care. This study systematically analyzes the authorships, reliability, quality, and readability of the websites, as well as the authorships and primary objectives of the videos regarding otoplasty. Validated instruments were used to analyze the reliability, quality, and readability of websites, and videos were systematically categorized and analyzed. A Google search was conducted, and the first five pages of results were included in this study. After excluding unrelated websites, the remaining 44 websites were categorized by authorship (physician, patient, academic, or unaffiliated) and were analyzed using the validated DISCERN instrument for reliability and quality, as well as various other validated instruments to measure readability. A YouTube search was also conducted, and the first 50 relevant videos were included in the study. These videos were categorized by authorship and their primary objective. Website authorships were physician-dominated. Reliability, quality, and overall DISCERN score differ between the four authorship groups by a statistically significant margin (Kruskall-Wallis test, p < 0.05). Unaffiliated websites were the most reliable, and physician websites were the least reliable. Academic websites were of the highest quality, and patient websites were of the lowest quality. Readability did not differ significantly between the groups, though the readability measurements made showed a general lack of material easily readable by the general public. YouTube was likewise dominated by physician-authored videos. While the physician-authored videos sought mainly to inform and to advertise, patient-authored videos sought mainly to provide the patient's perspective. Academic organizations showed very little representation on YouTube, and the YouTube views on otoplasty videos were dominated by the top 20 videos, which represented over 93% of the total views of videos included in this study. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.
Teaching Surgical Procedures with Movies: Tips for High-quality Video Clips.
Jacquemart, Mathieu; Bouletreau, Pierre; Breton, Pierre; Mojallal, Ali; Sigaux, Nicolas
2016-09-01
Video must now be considered as a precious tool for learning surgery. However, the medium does present production challenges, and currently, quality movies are not always accessible. We developed a series of 7 surgical videos and made them available on a publicly accessible internet website. Our videos have been viewed by thousands of people worldwide. High-quality educational movies must respect strategic and technical points to be reliable.
A no-reference video quality assessment metric based on ROI
NASA Astrophysics Data System (ADS)
Jia, Lixiu; Zhong, Xuefei; Tu, Yan; Niu, Wenjuan
2015-01-01
A no reference video quality assessment metric based on the region of interest (ROI) was proposed in this paper. In the metric, objective video quality was evaluated by integrating the quality of two compressed artifacts, i.e. blurring distortion and blocking distortion. The Gaussian kernel function was used to extract the human density maps of the H.264 coding videos from the subjective eye tracking data. An objective bottom-up ROI extraction model based on magnitude discrepancy of discrete wavelet transform between two consecutive frames, center weighted color opponent model, luminance contrast model and frequency saliency model based on spectral residual was built. Then only the objective saliency maps were used to compute the objective blurring and blocking quality. The results indicate that the objective ROI extraction metric has a higher the area under the curve (AUC) value. Comparing with the conventional video quality assessment metrics which measured all the video quality frames, the metric proposed in this paper not only decreased the computation complexity, but improved the correlation between subjective mean opinion score (MOS) and objective scores.
Adaptive UEP and Packet Size Assignment for Scalable Video Transmission over Burst-Error Channels
NASA Astrophysics Data System (ADS)
Lee, Chen-Wei; Yang, Chu-Sing; Su, Yih-Ching
2006-12-01
This work proposes an adaptive unequal error protection (UEP) and packet size assignment scheme for scalable video transmission over a burst-error channel. An analytic model is developed to evaluate the impact of channel bit error rate on the quality of streaming scalable video. A video transmission scheme, which combines the adaptive assignment of packet size with unequal error protection to increase the end-to-end video quality, is proposed. Several distinct scalable video transmission schemes over burst-error channel have been compared, and the simulation results reveal that the proposed transmission schemes can react to varying channel conditions with less and smoother quality degradation.
Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars; Sørensen, Torben Lykke; Thomsen, Ann Sofia Skou; Subhi, Yousif
2016-01-01
Direct ophthalmoscopy is well-suited for video-based instruction, particularly if the videos enable the student to see what the examiner sees when performing direct ophthalmoscopy. We evaluated the pedagogical effectiveness of instructional YouTube videos on direct ophthalmoscopy by evaluating their content and approach to visualization. In order to synthesize main themes and points for direct ophthalmoscopy, we formed a broad panel consisting of a medical student, junior and senior physicians, and took into consideration book chapters targeting medical students and physicians in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman's correlation. We screened 7,640 videos, of which 27 were found eligible for this study. Overall, a median of 12 out of 18 points (interquartile range: 8-14 key points) were covered; no videos covered all of the 18 points assessed. We found the most difficulties in the approach to visualization of how to approach the patient and how to examine the fundus. Time spent on fundus examination correlated with the number of views per week (Spearman's ρ=0.53; P=0.029). Videos may help overcome the pedagogical issues in teaching direct ophthalmoscopy; however, the few available videos on YouTube fail to address this particular issue adequately. There is a need for high-quality videos that include relevant points, provide realistic visualization of the examiner's view, and give particular emphasis on fundus examination.
Examining the effect of task on viewing behavior in videos using saliency maps
NASA Astrophysics Data System (ADS)
Alers, Hani; Redi, Judith A.; Heynderickx, Ingrid
2012-03-01
Research has shown that when viewing still images, people will look at these images in a different manner if instructed to evaluate their quality. They will tend to focus less on the main features of the image and, instead, scan the entire image area looking for clues for its level of quality. It is questionable, however, whether this finding can be extended to videos considering their dynamic nature. One can argue that when watching a video the viewer will always focus on the dynamically changing features of the video regardless of the given task. To test whether this is true, an experiment was conducted where half of the participants viewed videos with the task of quality evaluation while the other half were simply told to watch the videos as if they were watching a movie on TV or a video downloaded from the internet. The videos contained content which was degraded with compression artifacts over a wide range of quality. An eye tracking device was used to record the viewing behavior in both conditions. By comparing the behavior during each task, it was possible to observe a systematic difference in the viewing behavior which seemed to correlate to the quality of the videos.
A no-reference image and video visual quality metric based on machine learning
NASA Astrophysics Data System (ADS)
Frantc, Vladimir; Voronin, Viacheslav; Semenishchev, Evgenii; Minkin, Maxim; Delov, Aliy
2018-04-01
The paper presents a novel visual quality metric for lossy compressed video quality assessment. High degree of correlation with subjective estimations of quality is due to using of a convolutional neural network trained on a large amount of pairs video sequence-subjective quality score. We demonstrate how our predicted no-reference quality metric correlates with qualitative opinion in a human observer study. Results are shown on the EVVQ dataset with comparison existing approaches.
Objective assessment of MPEG-2 video quality
NASA Astrophysics Data System (ADS)
Gastaldo, Paolo; Zunino, Rodolfo; Rovetta, Stefano
2002-07-01
The increasing use of video compression standards in broadcasting television systems has required, in recent years, the development of video quality measurements that take into account artifacts specifically caused by digital compression techniques. In this paper we present a methodology for the objective quality assessment of MPEG video streams by using circular back-propagation feedforward neural networks. Mapping neural networks can render nonlinear relationships between objective features and subjective judgments, thus avoiding any simplifying assumption on the complexity of the model. The neural network processes an instantaneous set of input values, and yields an associated estimate of perceived quality. Therefore, the neural-network approach turns objective quality assessment into adaptive modeling of subjective perception. The objective features used for the estimate are chosen according to the assessed relevance to perceived quality and are continuously extracted in real time from compressed video streams. The overall system mimics perception but does not require any analytical model of the underlying physical phenomenon. The capability to process compressed video streams represents an important advantage over existing approaches, like avoiding the stream-decoding process greatly enhances real-time performance. Experimental results confirm that the system provides satisfactory, continuous-time approximations for actual scoring curves concerning real test videos.
A Completely Blind Video Integrity Oracle.
Mittal, Anish; Saad, Michele A; Bovik, Alan C
2016-01-01
Considerable progress has been made toward developing still picture perceptual quality analyzers that do not require any reference picture and that are not trained on human opinion scores of distorted images. However, there do not yet exist any such completely blind video quality assessment (VQA) models. Here, we attempt to bridge this gap by developing a new VQA model called the video intrinsic integrity and distortion evaluation oracle (VIIDEO). The new model does not require the use of any additional information other than the video being quality evaluated. VIIDEO embodies models of intrinsic statistical regularities that are observed in natural vidoes, which are used to quantify disturbances introduced due to distortions. An algorithm derived from the VIIDEO model is thereby able to predict the quality of distorted videos without any external knowledge about the pristine source, anticipated distortions, or human judgments of video quality. Even with such a paucity of information, we are able to show that the VIIDEO algorithm performs much better than the legacy full reference quality measure MSE on the LIVE VQA database and delivers performance comparable with a leading human judgment trained blind VQA model. We believe that the VIIDEO algorithm is a significant step toward making real-time monitoring of completely blind video quality possible.
Colonoscopy video quality assessment using hidden Markov random fields
NASA Astrophysics Data System (ADS)
Park, Sun Young; Sargent, Dusty; Spofford, Inbar; Vosburgh, Kirby
2011-03-01
With colonoscopy becoming a common procedure for individuals aged 50 or more who are at risk of developing colorectal cancer (CRC), colon video data is being accumulated at an ever increasing rate. However, the clinically valuable information contained in these videos is not being maximally exploited to improve patient care and accelerate the development of new screening methods. One of the well-known difficulties in colonoscopy video analysis is the abundance of frames with no diagnostic information. Approximately 40% - 50% of the frames in a colonoscopy video are contaminated by noise, acquisition errors, glare, blur, and uneven illumination. Therefore, filtering out low quality frames containing no diagnostic information can significantly improve the efficiency of colonoscopy video analysis. To address this challenge, we present a quality assessment algorithm to detect and remove low quality, uninformative frames. The goal of our algorithm is to discard low quality frames while retaining all diagnostically relevant information. Our algorithm is based on a hidden Markov model (HMM) in combination with two measures of data quality to filter out uninformative frames. Furthermore, we present a two-level framework based on an embedded hidden Markov model (EHHM) to incorporate the proposed quality assessment algorithm into a complete, automated diagnostic image analysis system for colonoscopy video.
Teaching Surgical Procedures with Movies: Tips for High-quality Video Clips
Jacquemart, Mathieu; Bouletreau, Pierre; Breton, Pierre; Mojallal, Ali
2016-01-01
Summary: Video must now be considered as a precious tool for learning surgery. However, the medium does present production challenges, and currently, quality movies are not always accessible. We developed a series of 7 surgical videos and made them available on a publicly accessible internet website. Our videos have been viewed by thousands of people worldwide. High-quality educational movies must respect strategic and technical points to be reliable. PMID:27757342
Leong, Amanda Y; Sanghera, Ravina; Jhajj, Jaspreet; Desai, Nandini; Jammu, Bikramjit Singh; Makowsky, Mark J
2017-12-25
To investigate the content, quality and popularity of information about type 2 diabetes available on YouTube. We searched YouTube with the terms Diabetes, Diabetes type 2, Diabetes South Asians, Diabetes Punjabi and Diabetes Hindi to identify videos concerning type 2 diabetes. A team of health-care providers independently classified the first 20 videos from each search as useful, misleading, or personal experience, rated them on a 5-point global quality scale (GQS) and categorized their content on a 26-point scale in duplicate. Useful videos were rated for reliability by using a 5-point modified DISCERN scale. Higher scores represent better quality, reliability and comprehensiveness. Of 100 videos, 71 met the inclusion criteria; 45 (63.4%) were rated as useful (median GQS, 3; interquartile range [IQR], 2 to 4); and 23 (32.4%) were deemed misleading (median GQS, 1; IQR, 1 to 2). Median reliability and content scores for useful videos were 3 (IQR, 2 to 3) and 5 (IQR, 3 to 10), respectively, and 6 videos met ≥ 4 of 5 reliability criteria. Overall, misleading videos were more popular than useful videos (median, 233 views/day; IQR, 26 to 523; vs. 8.3 views/day; IQR, 0.4 to 134.6; p<0.01). Culturally tailored videos were just as likely to be misleading and had similar GQS scores in comparison to nonculturally tailored videos (32.1% vs. 32.6% and 3 vs. 3, respectively). The quality of identified videos concerning type 2 diabetes was variable, and misleading videos were popular. Further creation and curation of high-quality video resources is required. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.
Liu, B; Wang, Z; Wu, G; Meng, X
2011-04-28
In this paper, we aim to study the cognitive integration of asynchronous natural or non-natural auditory and visual information in videos of real-world events. Videos with asynchronous semantically consistent or inconsistent natural sound or speech were used as stimuli in order to compare the difference and similarity between multisensory integrations of videos with asynchronous natural sound and speech. The event-related potential (ERP) results showed that N1 and P250 components were elicited irrespective of whether natural sounds were consistent or inconsistent with critical actions in videos. Videos with inconsistent natural sound could elicit N400-P600 effects compared to videos with consistent natural sound, which was similar to the results from unisensory visual studies. Videos with semantically consistent or inconsistent speech could both elicit N1 components. Meanwhile, videos with inconsistent speech would elicit N400-LPN effects in comparison with videos with consistent speech, which showed that this semantic processing was probably related to recognition memory. Moreover, the N400 effect elicited by videos with semantically inconsistent speech was larger and later than that elicited by videos with semantically inconsistent natural sound. Overall, multisensory integration of videos with natural sound or speech could be roughly divided into two stages. For the videos with natural sound, the first stage might reflect the connection between the received information and the stored information in memory; and the second one might stand for the evaluation process of inconsistent semantic information. For the videos with speech, the first stage was similar to the first stage of videos with natural sound; while the second one might be related to recognition memory process. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
Park, Jin-Seok; Kim, Min Su; Kim, HyungKil; Kim, Shin Il; Shin, Chun Ho; Lee, Hyun Jung; Lee, Won Seop; Moon, Soyoung
2016-06-17
High-quality bowel preparation is necessary for colonoscopy. A few studies have been conducted to investigate improvement in bowel preparation quality through patient education. However, the effect of patient education on bowel preparation has not been well studied. A randomized and prospective study was conducted. All patients received regular instruction for bowel preparation during a pre-colonoscopy visit. Those scheduled for colonoscopy were randomly assigned to view an educational video instruction (video group) on the day before the colonoscopy, or to a non-video (control) group. Qualities of bowel preparation using the Ottawa Bowel Preparation Quality scale (Ottawa score) were compared between the video and non-video groups. In addition, factors associated with poor bowel preparation were investigated. A total of 502 patients were randomized, 250 to the video group and 252 to the non-video group. The video group exhibited better bowel preparation (mean Ottawa total score: 3.03 ± 1.9) than the non-video group (4.21 ± 1.9; P < 0.001) and had good bowel preparation for colonoscopy (total Ottawa score <6: 91.6 % vs. 78.5 %; P < 0.001). Multivariate analysis revealed that males (odds ratio [OR] = 1.95, P = 0.029), diabetes mellitus patients (OR = 2.79, P = 0.021), and non-use of visual aids (OR = 3.09, P < 0.001) were associated with poor bowel preparation. In the comparison of the colonoscopic outcomes between groups, the polyp detection rate was not significantly different between video group and non-video group (48/250, 19.2 % vs. 48/252, 19.0 %; P = 0.963), but insertion time was significantly short in video group (5.5 ± 3.2 min) than non-video group (6.1 ± 3.7 min; P = 0.043). The addition of an educational video could improve the quality of bowel preparation in comparison with standard preparation method. Clinical Research Information Service KCT0001836 . The date of registration: March, 08(th), 2016, Retrospectively registered.
NASA Astrophysics Data System (ADS)
Manjanaik, N.; Parameshachari, B. D.; Hanumanthappa, S. N.; Banu, Reshma
2017-08-01
Intra prediction process of H.264 video coding standard used to code first frame i.e. Intra frame of video to obtain good coding efficiency compare to previous video coding standard series. More benefit of intra frame coding is to reduce spatial pixel redundancy with in current frame, reduces computational complexity and provides better rate distortion performance. To code Intra frame it use existing process Rate Distortion Optimization (RDO) method. This method increases computational complexity, increases in bit rate and reduces picture quality so it is difficult to implement in real time applications, so the many researcher has been developed fast mode decision algorithm for coding of intra frame. The previous work carried on Intra frame coding in H.264 standard using fast decision mode intra prediction algorithm based on different techniques was achieved increased in bit rate, degradation of picture quality(PSNR) for different quantization parameters. Many previous approaches of fast mode decision algorithms on intra frame coding achieved only reduction of computational complexity or it save encoding time and limitation was increase in bit rate with loss of quality of picture. In order to avoid increase in bit rate and loss of picture quality a better approach was developed. In this paper developed a better approach i.e. Gaussian pulse for Intra frame coding using diagonal down left intra prediction mode to achieve higher coding efficiency in terms of PSNR and bitrate. In proposed method Gaussian pulse is multiplied with each 4x4 frequency domain coefficients of 4x4 sub macro block of macro block of current frame before quantization process. Multiplication of Gaussian pulse for each 4x4 integer transformed coefficients at macro block levels scales the information of the coefficients in a reversible manner. The resulting signal would turn abstract. Frequency samples are abstract in a known and controllable manner without intermixing of coefficients, it avoids picture getting bad hit for higher values of quantization parameters. The proposed work was implemented using MATLAB and JM 18.6 reference software. The proposed work measure the performance parameters PSNR, bit rate and compression of intra frame of yuv video sequences in QCIF resolution under different values of quantization parameter with Gaussian value for diagonal down left intra prediction mode. The simulation results of proposed algorithm are tabulated and compared with previous algorithm i.e. Tian et al method. The proposed algorithm achieved reduced in bit rate averagely 30.98% and maintain consistent picture quality for QCIF sequences compared to previous algorithm i.e. Tian et al method.
YouTube as an information source for pediatric adenotonsillectomy and ear tube surgery.
Sorensen, Jeffrey A; Pusz, Max D; Brietzke, Scott E
2014-01-01
Assess the overall quality of information on adenotonsillectomy and ear tube surgery presented on YouTube (www.youtube.com) from the perspective of a parent or patient searching for information on surgery. The YouTube website was systematically searched on select dates with a formal search strategy to identify videos pertaining to pediatric adenotonsillectomy and ear tube surgery. Only videos with at least 5 (ear tube surgery) or 10 (adenotonsillectomy) views per day were included. Each video was viewed and scored by two independent scorers. Videos were categorized by goal and scored for video/audio quality, accuracy, comprehensiveness, and procedure-specific content. Cross-sectional study. Public domain website. Fifty-five videos were scored for adenotonsillectomy and forty-seven for ear tube surgery. The most common category was educational (65.3%) followed by testimonial (28.4%), and news program (9.8%). Testimonials were more common for adenotonsillectomy than ear tube surgery (41.8% vs. 12.8%, p=0.001). Testimonials had a significantly lower mean accuracy (2.23 vs. 2.62, p=0.02), comprehensiveness (1.71 vs. 2.22, p=0.007), and TA specific content (0.64 vs. 1.69, p=0.001) score than educational type videos. Only six videos (5.9%) received high scores in both video/audio quality and accuracy/comprehensiveness of content. There was no significant association between the accuracy and comprehensive score and views, posted "likes", posted "dislikes", and likes/dislikes ratio. There was an association between "likes" and mean video quality (Spearman's rho=0.262, p=0.008). Parents/patients searching YouTube for information on pediatric adenotonsillectomy and ear tube surgery will generally encounter low quality information with testimonials being common but of significantly lower quality. Viewer perceived quality ("likes") did not correlate to formally scored content quality. Published by Elsevier Ireland Ltd.
A quality assessment of cardiac auscultation material on YouTube.
Camm, Christian F; Sunderland, Nicholas; Camm, A John
2013-02-01
YouTube is a highly utilized Web site that contains a large amount of medical educational material. Although some studies have assessed the education material contained on the Web site, little analysis of cardiology content has been made. This study aimed to assess the quality of videos relating to heart sounds and murmurs contained on YouTube. We hypothesized that the quality of video files purporting to provide education on heart auscultation would be highly variable. Videos were searched for using the terms "heart sounds," "heart murmur," and "heart auscultation." A built-in educational filter was employed, and manual rejection of non-English language and nonrelated videos was undertaken. Remaining videos were analyzed for content, and suitable videos were scored using a purpose-built tool. YouTube search located 3350 videos in total, and of these, 22 were considered suitable for scoring. The average score was 4.07 out of 7 (standard deviation, 1.35). Six videos scored 5.5 or greater and 5 videos scoring 2.5 or less. There was no correlation between video score and YouTube indices of preference (hits, likes, dislikes, or search page). The quality of videos found in this study was highly variable. YouTube indications of preference were of no value in determining the value of video content. Therefore, teaching institutions or professional societies should endeavor to identify and highlight good online teaching resources. YouTube contains many videos relating to cardiac auscultation, but very few are valuable education resources. © 2012 Wiley Periodicals, Inc.
Enhanced video indirect ophthalmoscopy (VIO) via robust mosaicing.
Estrada, Rolando; Tomasi, Carlo; Cabrera, Michelle T; Wallace, David K; Freedman, Sharon F; Farsiu, Sina
2011-10-01
Indirect ophthalmoscopy (IO) is the standard of care for evaluation of the neonatal retina. When recorded on video from a head-mounted camera, IO images have low quality and narrow Field of View (FOV). We present an image fusion methodology for converting a video IO recording into a single, high quality, wide-FOV mosaic that seamlessly blends the best frames in the video. To this end, we have developed fast and robust algorithms for automatic evaluation of video quality, artifact detection and removal, vessel mapping, registration, and multi-frame image fusion. Our experiments show the effectiveness of the proposed methods.
Aghdasi, Hadi S; Abbaspour, Maghsoud; Moghadam, Mohsen Ebrahimi; Samei, Yasaman
2008-08-04
Technological progress in the fields of Micro Electro-Mechanical Systems (MEMS) and wireless communications and also the availability of CMOS cameras, microphones and small-scale array sensors, which may ubiquitously capture multimedia content from the field, have fostered the development of low-cost limited resources Wireless Video-based Sensor Networks (WVSN). With regards to the constraints of videobased sensor nodes and wireless sensor networks, a supporting video stream is not easy to implement with the present sensor network protocols. In this paper, a thorough architecture is presented for video transmission over WVSN called Energy-efficient and high-Quality Video transmission Architecture (EQV-Architecture). This architecture influences three layers of communication protocol stack and considers wireless video sensor nodes constraints like limited process and energy resources while video quality is preserved in the receiver side. Application, transport, and network layers are the layers in which the compression protocol, transport protocol, and routing protocol are proposed respectively, also a dropping scheme is presented in network layer. Simulation results over various environments with dissimilar conditions revealed the effectiveness of the architecture in improving the lifetime of the network as well as preserving the video quality.
YouTube Videos on Botulinum Toxin A for Wrinkles: A Useful Resource for Patient Education.
Wong, Katharine; Doong, Judy; Trang, Trinh; Joo, Sarah; Chien, Anna L
2017-12-01
Patients interested in botulinum toxin type A (BTX-A) for wrinkles search for videos on YouTube, but little is known about the quality and reliability of the content. The authors examined the quality, reliability, content, and target audience of YouTube videos on BTX for wrinkles. In this cross-sectional study, the term "Botox" was searched on YouTube. Sixty relevant videos in English were independently categorized by 2 reviewers as useful informational, misleading informational, useful patient view, or misleading patient view. Disagreements were settled by a third reviewer. Videos were rated on the Global Quality Scale (GQS) (1 = poor, 5 = excellent). Sixty-three percent of the BTX YouTube videos were useful informational (GQS = 4.4 ± 0.7), 33% as useful patient view (GQS = 3.21 ± 1.2), 2% as misleading informational (GQS = 1), and 2% as misleading patient view (GQS = 2.5). The large number of useful videos, high reliability, and the wide range of content covered suggests that those who search for antiwrinkle BTX videos on YouTube are likely to view high-quality content. This suggests that YouTube may be a good source of videos to recommend for patients interested in BTX.
Toward a perceptual video-quality metric
NASA Astrophysics Data System (ADS)
Watson, Andrew B.
1998-07-01
The advent of widespread distribution of digital video creates a need for automated methods for evaluating the visual quality of digital video. This is particularly so since most digital video is compressed using lossy methods, which involve the controlled introduction of potentially visible artifacts. Compounding the problem is the bursty nature of digital video, which requires adaptive bit allocation based on visual quality metrics, and the economic need to reduce bit-rate to the lowest level that yields acceptable quality. In previous work, we have developed visual quality metrics for evaluating, controlling,a nd optimizing the quality of compressed still images. These metrics incorporate simplified models of human visual sensitivity to spatial and chromatic visual signals. Here I describe a new video quality metric that is an extension of these still image metrics into the time domain. Like the still image metrics, it is based on the Discrete Cosine Transform. An effort has been made to minimize the amount of memory and computation required by the metric, in order that might be applied in the widest range of applications. To calibrate the basic sensitivity of this metric to spatial and temporal signals we have made measurements of visual thresholds for temporally varying samples of DCT quantization noise.
NASA Technical Reports Server (NTRS)
Scott, D. W.
1994-01-01
This report describes efforts to use digital motion video compression technology to develop a highly portable device that would convert 1990-91 era IBM-compatible and/or MacIntosh notebook computers into full-color, motion-video capable multimedia training systems. An architecture was conceived that would permit direct conversion of existing laser-disk-based multimedia courses with little or no reauthoring. The project did not physically demonstrate certain critical video keying techniques, but their implementation should be feasible. This investigation of digital motion video has spawned two significant spaceflight projects at MSFC: one to downlink multiple high-quality video signals from Spacelab, and the other to uplink videoconference-quality video in realtime and high quality video off-line, plus investigate interactive, multimedia-based techniques for enhancing onboard science operations. Other airborne or spaceborne spinoffs are possible.
Thin-slice vision: inference of confidence measure from perceptual video quality
NASA Astrophysics Data System (ADS)
Hameed, Abdul; Balas, Benjamin; Dai, Rui
2016-11-01
There has been considerable research on thin-slice judgments, but no study has demonstrated the predictive validity of confidence measures when assessors watch videos acquired from communication systems, in which the perceptual quality of videos could be degraded by limited bandwidth and unreliable network conditions. This paper studies the relationship between high-level thin-slice judgments of human behavior and factors that contribute to perceptual video quality. Based on a large number of subjective test results, it has been found that the confidence of a single individual present in all the videos, called speaker's confidence (SC), could be predicted by a list of features that contribute to perceptual video quality. Two prediction models, one based on artificial neural network and the other based on a decision tree, were built to predict SC. Experimental results have shown that both prediction models can result in high correlation measures.
Visual Perception Based Rate Control Algorithm for HEVC
NASA Astrophysics Data System (ADS)
Feng, Zeqi; Liu, PengYu; Jia, Kebin
2018-01-01
For HEVC, rate control is an indispensably important video coding technology to alleviate the contradiction between video quality and the limited encoding resources during video communication. However, the rate control benchmark algorithm of HEVC ignores subjective visual perception. For key focus regions, bit allocation of LCU is not ideal and subjective quality is unsatisfied. In this paper, a visual perception based rate control algorithm for HEVC is proposed. First bit allocation weight of LCU level is optimized based on the visual perception of luminance and motion to ameliorate video subjective quality. Then λ and QP are adjusted in combination with the bit allocation weight to improve rate distortion performance. Experimental results show that the proposed algorithm reduces average 0.5% BD-BR and maximum 1.09% BD-BR at no cost in bitrate accuracy compared with HEVC (HM15.0). The proposed algorithm devotes to improving video subjective quality under various video applications.
Rice, Sean C; Higginbotham, Tina; Dean, Melanie J; Slaughter, James C; Yachimski, Patrick S; Obstein, Keith L
2016-11-01
Successful outpatient colonoscopy (CLS) depends on many factors including the quality of a patient's bowel preparation. Although education on consumption of the pre-CLS purgative can improve bowel preparation quality, no study has evaluated dietary education alone. We have created an educational video on pre-CLS dietary instructions to determine whether dietary education would improve outpatient bowel preparation quality. A prospective randomized, blinded, controlled study of patients undergoing outpatient CLS was performed. All patients received a 4 l polyethylene glycol-based split-dose bowel preparation and standard institutional pre-procedure instructions. Patients were then randomly assigned to an intervention arm or to a no intervention arm. A 4-min educational video detailing clear liquid diet restriction was made available to patients in the intervention arm, whereas those randomized to no intervention did not have access to the video. Patients randomized to the video were provided with the YouTube video link 48-72 h before CLS. An attending endoscopist blinded to randomization performed the CLS. Bowel preparation quality was scored using the Boston Bowel Preparation Scale (BBPS). Adequate preparation was defined as a BBPS total score of ≥6 with all segment scores ≥2. Wilcoxon rank-sum and Pearson's χ 2 -tests were performed to assess differences between groups. Ninety-two patients were randomized (video: n=42; control: n=50) with 47 total video views being tallied. There were no demographic differences between groups. There was no statistically significant difference in adequate preparation between groups (video=74%; control=68%; P=0.54). The availability of a supplementary patient educational video on clear liquid diet alone was insufficient to improve bowel preparation quality when compared with standard pre-procedure instruction at our institution.
Peltier, Alexandre; Aoun, Fouad; Ameye, Filip; Andrianne, Robert; De Meerleer, Gert; Denis, Louis; Joniau, Steven; Lambrecht, Antoon; Billiet, Ignace; Vanderdonck, Frank; Roumeguère, Thierry; Van Velthoven, Roland
2015-09-01
This large multicenter study aimed to assess the impact of the use of multimedia tools on the duration and the quality of the conversation between healthcare providers (urologists, radiotherapists and nurses) and their patients. 30 urological centers in Belgium used either videos or other instructive tools in their consultation with prostate cancer patients. Each consultation was evaluated for duration and quality using a visual analog scale. In total, 905 patient visits were evaluated: 447 without and 458 with video support. During consultations with video support, an average of 2.3 videos was shown. Video support was judged to be practical and to improve the quality of consultations, without loss of time, regardless of patient age or stage of disease management (p > 0.05). Healthcare providers indicate that the use of videos improved patient comprehension about prostate cancer, as well as the quality information exchange, without increasing consultation time. The use of video material was feasible in daily practice, and was easy to understand, relevant and culturally appropriate, even for the most elderly men. Multimedia education also helped to empower men to actively participate in their healthcare and treatment discussions. Ipsen NV.
Trans-Pacific tele-ultrasound image transmission of fetal central nervous system structures.
Ferreira, Adilson Cunha; Araujo Júnior, Edward; Martins, Wellington P; Jordão, João Francisco; Oliani, Antônio Hélio; Meagher, Simon E; Da Silva Costa, Fabricio
2015-01-01
To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia. In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests. The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI = 66.4-86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI = 70.0-80.8%) the scores of transmitted image were considered the same as the original. We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality.
Caffery, Liam J; Smith, Anthony C
2015-09-01
The use of fourth-generation (4G) mobile telecommunications to provide real-time video consultations were investigated in this study with the aims of determining if 4G is a suitable telecommunications technology; and secondly, to identify if variation in perceived audio and video quality were due to underlying network performance. Three patient end-points that used 4G Internet connections were evaluated. Consulting clinicians recorded their perception of audio and video quality using the International Telecommunications Union scales during clinics with these patient end-points. These scores were used to calculate a mean opinion score (MOS). The network performance metrics were obtained for each session and the relationships between these metrics and the session's quality scores were tested. Clinicians scored the quality of 50 hours of video consultations, involving 36 clinic sessions. The MOS for audio was 4.1 ± 0.62 and the MOS for video was 4.4 ± 0.22. Image impairment and effort to listen were also rated favourably. There was no correlation between audio or video quality and the network metrics of packet loss or jitter. These findings suggest that 4G networks are an appropriate telecommunication technology to deliver real-time video consultations. Variations in quality scores observed during this study were not explained by the packet loss and jitter in the underlying network. Before establishing a telemedicine service, the performance of the 4G network should be assessed at the location of the proposed service. This is due to known variability in performance of 4G networks. © The Author(s) 2015.
How useful is YouTube in learning heart anatomy?
Raikos, Athanasios; Waidyasekara, Pasan
2014-01-01
Nowadays more and more modern medical degree programs focus on self-directed and problem-based learning. That requires students to search for high quality and easy to retrieve online resources. YouTube is an emerging platform for learning human anatomy due to easy access and being a free service. The purpose of this study is to make a quantitative and qualitative analysis of the available human heart anatomy videos on YouTube. Using the search engine of the platform we searched for relevant videos using various keywords. Videos with irrelevant content, animal tissue, non-English language, no sound, duplicates, and physiology focused were excluded from further elaboration. The initial search retrieved 55,525 videos, whereas only 294 qualified for further analysis. A unique scoring system was used to assess the anatomical quality and details, general quality, and the general data for each video. Our results indicate that the human heart anatomy videos available on YouTube conveyed our anatomical criteria poorly, whereas the general quality scoring found borderline. Students should be selective when looking up on public video databases as it can prove challenging, time consuming, and the anatomical information may be misleading due to absence of content review. Anatomists and institutions are encouraged to prepare and endorse good quality material and make them available online for the students. The scoring rubric used in the study comprises a valuable tool to faculty members for quality evaluation of heart anatomy videos available on social media platforms. Copyright © 2013 American Association of Anatomists.
Thiemann, K S; Goldstein, H
2001-01-01
This study investigated the effects of written text and pictorial cuing with supplemental video feedback on the social communication of 5 students with autism and social deficits. Two peers without disabilities participated as social partners with each child with autism to form five triads. Treatment was implemented twice per week and consisted of 10 min of systematic instruction using visual stimuli, 10 min of social interaction, and 10 min of self-evaluation using video feedback. Results showed increases in targeted social communication skills when the treatment was implemented. Some generalized treatment effects were observed across untrained social behaviors, and 1 participant generalized improvements within the classroom. In addition, naive judges reported perceived improvements in the quality of reciprocal interactions. These findings support recommendations for using visually cued instruction to guide the social language development of young children with autism as they interact with peers without disabilities. PMID:11800183
Tracking and recognition face in videos with incremental local sparse representation model
NASA Astrophysics Data System (ADS)
Wang, Chao; Wang, Yunhong; Zhang, Zhaoxiang
2013-10-01
This paper addresses the problem of tracking and recognizing faces via incremental local sparse representation. First a robust face tracking algorithm is proposed via employing local sparse appearance and covariance pooling method. In the following face recognition stage, with the employment of a novel template update strategy, which combines incremental subspace learning, our recognition algorithm adapts the template to appearance changes and reduces the influence of occlusion and illumination variation. This leads to a robust video-based face tracking and recognition with desirable performance. In the experiments, we test the quality of face recognition in real-world noisy videos on YouTube database, which includes 47 celebrities. Our proposed method produces a high face recognition rate at 95% of all videos. The proposed face tracking and recognition algorithms are also tested on a set of noisy videos under heavy occlusion and illumination variation. The tracking results on challenging benchmark videos demonstrate that the proposed tracking algorithm performs favorably against several state-of-the-art methods. In the case of the challenging dataset in which faces undergo occlusion and illumination variation, and tracking and recognition experiments under significant pose variation on the University of California, San Diego (Honda/UCSD) database, our proposed method also consistently demonstrates a high recognition rate.
Lin, Frank Yeong-Sung; Hsiao, Chiu-Han; Yen, Hong-Hsu; Hsieh, Yu-Jen
2013-01-01
One of the important applications in Wireless Sensor Networks (WSNs) is video surveillance that includes the tasks of video data processing and transmission. Processing and transmission of image and video data in WSNs has attracted a lot of attention in recent years. This is known as Wireless Visual Sensor Networks (WVSNs). WVSNs are distributed intelligent systems for collecting image or video data with unique performance, complexity, and quality of service challenges. WVSNs consist of a large number of battery-powered and resource constrained camera nodes. End-to-end delay is a very important Quality of Service (QoS) metric for video surveillance application in WVSNs. How to meet the stringent delay QoS in resource constrained WVSNs is a challenging issue that requires novel distributed and collaborative routing strategies. This paper proposes a Near-Optimal Distributed QoS Constrained (NODQC) routing algorithm to achieve an end-to-end route with lower delay and higher throughput. A Lagrangian Relaxation (LR)-based routing metric that considers the “system perspective” and “user perspective” is proposed to determine the near-optimal routing paths that satisfy end-to-end delay constraints with high system throughput. The empirical results show that the NODQC routing algorithm outperforms others in terms of higher system throughput with lower average end-to-end delay and delay jitter. In this paper, for the first time, the algorithm shows how to meet the delay QoS and at the same time how to achieve higher system throughput in stringently resource constrained WVSNs.
Rössler, Bernhard; Lahner, Daniel; Schebesta, Karl; Chiari, Astrid; Plöchl, Walter
2012-07-01
The Internet has become the largest, most up-to-date source for medical information. Besides enhancing patients' knowledge, the freely accessible audio-visual files have an impact on medical education. However little is known about their characteristics. In this manuscript the quality of lumbar puncture (LP) and spinal anaesthesia (SA) videos available on YouTube is assessed. This retrospective analysis was based on a search for LP and SA on YouTube. Videos were evaluated using essential key points (5 in SA, 4 in LP) and 3 safety indicators. Furthermore, violation of sterile working techniques and a rating whether the video must be regarded as dangerously misleading was performed. From 2321 hits matching the keywords, 38 videos were eligible for evaluation. In LP videos, 14% contained information on all, 4.5% on 3 and 4.5% on 2 key points, 59% on 1 and 18% on no key point. Regarding SA, no video contained information on all 5 key points, 56% on 2-4 and 25% on 1 key point, 19% did not contain any essential information. A sterility violation occurred in 11%, and 13% were classified as dangerously misleading. Even though high quality videos are available, the quality of video clips is generally low. The fraction of videos that were not performed in an aseptic manner is low, but these pose a substantial risk to patients. Consequently, more high-quality, institutional medical learning videos must be made available in the light of the increased utilization on the Internet. Copyright © 2012 Elsevier B.V. All rights reserved.
Yoon, Bo Young; Choi, Ikseon; Choi, Seokjin; Kim, Tae-Hee; Roh, Hyerin; Rhee, Byoung Doo; Lee, Jong-Tae
2016-06-01
The quality of problem representation is critical for developing students' problem-solving abilities in problem-based learning (PBL). This study investigates preclinical students' experience with standardized patients (SPs) as a problem representation method compared to using video cases in PBL. A cohort of 99 second-year preclinical students from Inje University College of Medicine (IUCM) responded to a Likert scale questionnaire on their learning experiences after they had experienced both video cases and SPs in PBL. The questionnaire consisted of 14 items with eight subcategories: problem identification, hypothesis generation, motivation, collaborative learning, reflective thinking, authenticity, patient-doctor communication, and attitude toward patients. The results reveal that using SPs led to the preclinical students having significantly positive experiences in boosting patient-doctor communication skills; the perceived authenticity of their clinical situations; development of proper attitudes toward patients; and motivation, reflective thinking, and collaborative learning when compared to using video cases. The SPs also provided more challenges than the video cases during problem identification and hypotheses generation. SPs are more effective than video cases in delivering higher levels of authenticity in clinical problems for PBL. The interaction with SPs engages preclinical students in deeper thinking and discussion; growth of communication skills; development of proper attitudes toward patients; and motivation. Considering the higher cost of SPs compared with video cases, SPs could be used most advantageously during the preclinical period in the IUCM curriculum.
Turel, O; Romashkin, A; Morrison, K M
2017-08-01
There is a growing need to curb paediatric obesity. The aim of this study is to untangle associations between video-game-use attributes and obesity as a first step towards identifying and examining possible interventions. Cross-sectional time-lagged cohort study was employed using parent-child surveys (t1) and objective physical activity and physiological measures (t2) from 125 children/adolescents (mean age = 13.06, 9-17-year-olds) who play video games, recruited from two clinics at a Canadian academic children's hospital. Structural equation modelling and analysis of covariance were employed for inference. The results of the study are as follows: (i) self-reported video-game play duration in the 4-h window before bedtime is related to greater abdominal adiposity (waist-to-height ratio) and this association may be mediated through reduced sleep quality (measured with the Pittsburgh Sleep Quality Index); and (ii) self-reported average video-game session duration is associated with greater abdominal adiposity and this association may be mediated through higher self-reported sweet drinks consumption while playing video games and reduced sleep quality. Video-game play duration in the 4-h window before bedtime, typical video-game session duration, sweet drinks consumption while playing video games and poor sleep quality have aversive associations with abdominal adiposity. Paediatricians and researchers should further explore how these factors can be altered through behavioural or pharmacological interventions as a means to reduce paediatric obesity. © 2017 World Obesity Federation.
NASA Astrophysics Data System (ADS)
Kim, Kyung-Su; Lee, Hae-Yeoun; Im, Dong-Hyuck; Lee, Heung-Kyu
Commercial markets employ digital right management (DRM) systems to protect valuable high-definition (HD) quality videos. DRM system uses watermarking to provide copyright protection and ownership authentication of multimedia contents. We propose a real-time video watermarking scheme for HD video in the uncompressed domain. Especially, our approach is in aspect of practical perspectives to satisfy perceptual quality, real-time processing, and robustness requirements. We simplify and optimize human visual system mask for real-time performance and also apply dithering technique for invisibility. Extensive experiments are performed to prove that the proposed scheme satisfies the invisibility, real-time processing, and robustness requirements against video processing attacks. We concentrate upon video processing attacks that commonly occur in HD quality videos to display on portable devices. These attacks include not only scaling and low bit-rate encoding, but also malicious attacks such as format conversion and frame rate change.
Aléx, Jonas; Gyllencreutz, Lina
2018-02-05
Trauma care at an accident site is of great importance for patient survival. The purpose of the study was to observe the compliance of ambulance nurses with the Prehospital Trauma Life Support (PHTLS) concept of trauma care in a simulation situation. The material consisted of video recordings in trauma simulation and an observation protocol was designed to analyze the video material. The result showed weaknesses in systematic exam and an ineffective use of time at the scene of injury. Development of observation protocols in trauma simulation can ensure the quality of ambulance nurses' compliance with established concepts. Our pilot study shows that insufficiencies in systematic care lead to an ineffective treatment for trauma patients which in turn may increase the risk of complications and mortality.
Hemmati Maslakpak, Masumeh; Shams, Shadi
2015-01-01
Background End stage renal disease negatively affects the patients’ quality of life. There are different educational methods to help these patients. This study was performed to compare the effectiveness of self-care education in two methods, face to face and video educational, on the quality of life in patients under treatment by hemodialysis in education-medical centers in Urmia. Methods In this quasi-experimental study, 120 hemodialysis patients were selected randomly; they were then randomly allocated to three groups: the control, face to face education and video education. For face to face group, education was given individually in two sessions of 35 to 45 minutes. For video educational group, CD was shown. Kidney Disease Quality Of Life- Short Form (KDQOL-SF) questionnaire was filled out before and two months after the intervention. Data analysis was performed in SPSS software by using one-way ANOVA. Results ANOVA test showed a statistically significant difference in the quality of life scores among the three groups after the intervention (P=0.024). After the intervention, Tukey’s post-hoc test showed a statistically significant difference between the two groups of video and face to face education regarding the quality of life (P>0.05). Conclusion Implementation of the face to face and video education methods improves the quality of life in hemodialysis patients. So, it is suggested that video educational should be used along with face to face education. PMID:26171412
Analysis of the color rendition of flexible endoscopes
NASA Astrophysics Data System (ADS)
Murphy, Edward M.; Hegarty, Francis J.; McMahon, Barry P.; Boyle, Gerard
2003-03-01
Endoscopes are imaging devices routinely used for the diagnosis of disease within the human digestive tract. Light is transmitted into the body cavity via incoherent fibreoptic bundles and is controlled by a light feedback system. Fibreoptic endoscopes use coherent fibreoptic bundles to provide the clinician with an image. It is also possible to couple fibreoptic endoscopes to a clip-on video camera. Video endoscopes consist of a small CCD camera, which is inserted into gastrointestinal tract, and associated image processor to convert the signal to analogue RGB video signals. Images from both types of endoscope are displayed on standard video monitors. Diagnosis is dependent upon being able to determine changes in the structure and colour of tissues and biological fluids, and therefore is dependent upon the ability of the endoscope to reproduce the colour of these tissues and fluids with fidelity. This study investigates the colour reproduction of flexible optical and video endoscopes. Fibreoptic and video endoscopes alter image colour characteristics in different ways. The colour rendition of fibreoptic endoscopes was assessed by coupling them to a video camera and applying video colorimetric techniques. These techniques were then used on video endoscopes to assess how the colour rendition of video endoscopes compared with that of optical endoscopes. In both cases results were obtained at fixed illumination settings. Video endoscopes were then assessed with varying levels of illumination. Initial results show that at constant luminance endoscopy systems introduce non-linear shifts in colour. Techniques for examining how this colour shift varies with illumination intensity were developed and both methodology and results will be presented. We conclude that more rigorous quality assurance is required to reduce colour error and are developing calibration procedures applicable to medical endoscopes.
Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars; Sørensen, Torben Lykke; Thomsen, Ann Sofia Skou; Subhi, Yousif
2016-01-01
Background Direct ophthalmoscopy is well-suited for video-based instruction, particularly if the videos enable the student to see what the examiner sees when performing direct ophthalmoscopy. We evaluated the pedagogical effectiveness of instructional YouTube videos on direct ophthalmoscopy by evaluating their content and approach to visualization. Methods In order to synthesize main themes and points for direct ophthalmoscopy, we formed a broad panel consisting of a medical student, junior and senior physicians, and took into consideration book chapters targeting medical students and physicians in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman’s correlation. Results We screened 7,640 videos, of which 27 were found eligible for this study. Overall, a median of 12 out of 18 points (interquartile range: 8–14 key points) were covered; no videos covered all of the 18 points assessed. We found the most difficulties in the approach to visualization of how to approach the patient and how to examine the fundus. Time spent on fundus examination correlated with the number of views per week (Spearman’s ρ=0.53; P=0.029). Conclusion Videos may help overcome the pedagogical issues in teaching direct ophthalmoscopy; however, the few available videos on YouTube fail to address this particular issue adequately. There is a need for high-quality videos that include relevant points, provide realistic visualization of the examiner’s view, and give particular emphasis on fundus examination. PMID:27574393
About subjective evaluation of adaptive video streaming
NASA Astrophysics Data System (ADS)
Tavakoli, Samira; Brunnström, Kjell; Garcia, Narciso
2015-03-01
The usage of HTTP Adaptive Streaming (HAS) technology by content providers is increasing rapidly. Having available the video content in multiple qualities, using HAS allows to adapt the quality of downloaded video to the current network conditions providing smooth video-playback. However, the time-varying video quality by itself introduces a new type of impairment. The quality adaptation can be done in different ways. In order to find the best adaptation strategy maximizing users perceptual quality it is necessary to investigate about the subjective perception of adaptation-related impairments. However, the novelties of these impairments and their comparably long time duration make most of the standardized assessment methodologies fall less suited for studying HAS degradation. Furthermore, in traditional testing methodologies, the quality of the video in audiovisual services is often evaluated separated and not in the presence of audio. Nevertheless, the requirement of jointly evaluating the audio and the video within a subjective test is a relatively under-explored research field. In this work, we address the research question of determining the appropriate assessment methodology to evaluate the sequences with time-varying quality due to the adaptation. This was done by studying the influence of different adaptation related parameters through two different subjective experiments using a methodology developed to evaluate long test sequences. In order to study the impact of audio presence on quality assessment by the test subjects, one of the experiments was done in the presence of audio stimuli. The experimental results were subsequently compared with another experiment using the standardized single stimulus Absolute Category Rating (ACR) methodology.
NASA Astrophysics Data System (ADS)
Radun, Jenni E.; Virtanen, Toni; Olives, Jean-Luc; Vaahteranoksa, Mikko; Vuori, Tero; Nyman, Göte
2007-01-01
We present an effective method for comparing subjective audiovisual quality and the features related to the quality changes of different video cameras. Both quantitative estimation of overall quality and qualitative description of critical quality features are achieved by the method. The aim was to combine two image quality evaluation methods, the quantitative Absolute Category Rating (ACR) method with hidden reference removal and the qualitative Interpretation- Based Quality (IBQ) method in order to see how they complement each other in audiovisual quality estimation tasks. 26 observers estimated the audiovisual quality of six different cameras, mainly mobile phone video cameras. In order to achieve an efficient subjective estimation of audiovisual quality, only two contents with different quality requirements were recorded with each camera. The results show that the subjectively important quality features were more related to the overall estimations of cameras' visual video quality than to the features related to sound. The data demonstrated two significant quality dimensions related to visual quality: darkness and sharpness. We conclude that the qualitative methodology can complement quantitative quality estimations also with audiovisual material. The IBQ approach is valuable especially, when the induced quality changes are multidimensional.
Stochastic Packet Loss Model to Evaluate QoE Impairments
NASA Astrophysics Data System (ADS)
Hohlfeld, Oliver
With provisioning of broadband access for mass market—even in wireless and mobile networks—multimedia content, especially real-time streaming of high-quality audio and video, is extensively viewed and exchanged over the Internet. Quality of Experience (QoE) aspects, describing the service quality perceived by the user, is a vital factor in ensuring customer satisfaction in today's communication networks. Frameworks for accessing quality degradations in streamed video currently are investigated as a complex multi-layered research topic, involving network traffic load, codec functions and measures of user perception of video quality.
A qualitative analysis of methotrexate self-injection education videos on YouTube.
Rittberg, Rebekah; Dissanayake, Tharindri; Katz, Steven J
2016-05-01
The aim of this study is to identify and evaluate the quality of videos for patients available on YouTube for learning to self-administer subcutaneous methotrexate. Using the search term "Methotrexate injection," two clinical reviewers analyzed the first 60 videos on YouTube. Source and search rank of video, audience interaction, video duration, and time since video was uploaded on YouTube were recorded. Videos were classified as useful, misleading, or a personal patient view. Videos were rated for reliability, comprehensiveness, and global quality scale (GQS). Reasons for misleading videos were documented, and patient videos were documented as being either positive or negative towards methotrexate (MTX) injection. Fifty-one English videos overlapped between the two geographic locations; 10 videos were classified as useful (19.6 %), 14 misleading (27.5 %), and 27 personal patient view (52.9 %). Total views of videos were 161,028: 19.2 % useful, 72.8 % patient, and 8.0 % misleading. Mean GQS: 4.2 (±1.0) useful, 1.6 (±1.1) misleading, and 2.0 (±0.9) for patient videos (p < 0.0001). Mean reliability: 3.3 (±0.6) useful, 0.9 (±1.2) misleading, and 1.0 (±0.7) for patient videos (p < 0.0001). Comprehensiveness: 2.2 (±1.9) useful, 0.1 (±0.3) misleading, and 1.5 (±1.5) for patient view videos (p = 0.0027). This study demonstrates a minority of videos are useful for teaching MTX injection. Further, video quality does not correlate with video views. While web video may be an additional educational tool available, clinicians need to be familiar with specific resources to help guide and educate their patients to ensure best outcomes.
Hudali, Tamer; Bhattarai, Mukul; Deckard, Alan; Hingle, Susan
2017-01-01
Background Hospital medicine is a relatively new specialty field, dedicated to the delivery of comprehensive medical care to hospitalized patients. YouTube is one of the most frequently used websites, offering access to a gamut of videos from self-produced to professionally made. Objective The aim of our study was to determine the adequacy of YouTube as an effective means to define and depict the role of hospitalists. Methods YouTube was searched on November 17, 2014, using the following search words: “hospitalist,” “hospitalist definition,” “what is the role of a hospitalist,” “define hospitalist,” and “who is a hospitalist.” Videos found only in the first 10 pages of each search were included. Non-English, noneducational, and nonrelevant videos were excluded. A novel 7-point scoring tool was created by the authors based on the definition of a hospitalist adopted by the Society of Hospital Medicine. Three independent reviewers evaluated, scored, and classified the videos into high, intermediate, and low quality based on the average score. Results A total of 102 videos out of 855 were identified as relevant and included in the analysis. Videos uploaded by academic institutions had the highest mean score. Only 6 videos were classified as high quality, 53 as intermediate quality, and 42 as low quality, with 82.4% (84/102) of the videos scoring an average of 4 or less. Conclusions Most videos found in the search of a hospitalist definition are inadequate. Leading medical organizations and academic institutions should consider producing and uploading quality videos to YouTube to help patients and their families better understand the roles and definition of the hospitalist. PMID:28073738
No-Reference Video Quality Assessment Based on Statistical Analysis in 3D-DCT Domain.
Li, Xuelong; Guo, Qun; Lu, Xiaoqiang
2016-05-13
It is an important task to design models for universal no-reference video quality assessment (NR-VQA) in multiple video processing and computer vision applications. However, most existing NR-VQA metrics are designed for specific distortion types which are not often aware in practical applications. A further deficiency is that the spatial and temporal information of videos is hardly considered simultaneously. In this paper, we propose a new NR-VQA metric based on the spatiotemporal natural video statistics (NVS) in 3D discrete cosine transform (3D-DCT) domain. In the proposed method, a set of features are firstly extracted based on the statistical analysis of 3D-DCT coefficients to characterize the spatiotemporal statistics of videos in different views. These features are used to predict the perceived video quality via the efficient linear support vector regression (SVR) model afterwards. The contributions of this paper are: 1) we explore the spatiotemporal statistics of videos in 3DDCT domain which has the inherent spatiotemporal encoding advantage over other widely used 2D transformations; 2) we extract a small set of simple but effective statistical features for video visual quality prediction; 3) the proposed method is universal for multiple types of distortions and robust to different databases. The proposed method is tested on four widely used video databases. Extensive experimental results demonstrate that the proposed method is competitive with the state-of-art NR-VQA metrics and the top-performing FR-VQA and RR-VQA metrics.
Hickman, Simon J
2016-03-01
Internet video sharing sites allow the free dissemination of educational material. This study investigated the quality and educational content of videos of eye movement disorders posted on such sites. Educational neurological eye movement videos were identified by entering the titles of the eye movement abnormality into the search boxes of the video sharing sites. Also, suggested links were followed from each video. The number of views, likes, and dislikes for each video were recorded. The videos were then rated for their picture and sound quality. Their educational value was assessed according to whether the video included a description of the eye movement abnormality, the anatomical location of the lesion (if appropriate), and the underlying diagnosis. Three hundred fifty-four of these videos were found on YouTube and Vimeo. There was a mean of 6,443 views per video (range, 1-195,957). One hundred nineteen (33.6%) had no form of commentary about the eye movement disorder shown apart from the title. Forty-seven (13.3%) contained errors in the title or in the text. Eighty (22.6%) had excellent educational value by describing the eye movement abnormality, the anatomical location of the lesion, and the underlying diagnosis. Of these, 30 also had good picture and sound quality. The videos with excellent educational value had a mean of 9.84 "likes" per video compared with 2.37 for those videos without a commentary (P < 0.001). The videos that combined excellent educational value with good picture and sound quality had a mean of 10.23 "likes" per video (P = 0.004 vs videos with no commentary). There was no significant difference in the mean number of "dislikes" between those videos that had no commentary or which contained errors and those with excellent educational value. There are a large number of eye movement videos freely available on these sites; however, due to the lack of peer review, a significant number have poor educational value due to having no commentary or containing errors. The number of "likes" can help to identify videos with excellent educational value but the number of "dislikes" does not help in discerning which videos have poor educational value.
Learning a Continuous-Time Streaming Video QoE Model.
Ghadiyaram, Deepti; Pan, Janice; Bovik, Alan C
2018-05-01
Over-the-top adaptive video streaming services are frequently impacted by fluctuating network conditions that can lead to rebuffering events (stalling events) and sudden bitrate changes. These events visually impact video consumers' quality of experience (QoE) and can lead to consumer churn. The development of models that can accurately predict viewers' instantaneous subjective QoE under such volatile network conditions could potentially enable the more efficient design of quality-control protocols for media-driven services, such as YouTube, Amazon, Netflix, and so on. However, most existing models only predict a single overall QoE score on a given video and are based on simple global video features, without accounting for relevant aspects of human perception and behavior. We have created a QoE evaluator, called the time-varying QoE Indexer, that accounts for interactions between stalling events, analyzes the spatial and temporal content of a video, predicts the perceptual video quality, models the state of the client-side data buffer, and consequently predicts continuous-time quality scores that agree quite well with human opinion scores. The new QoE predictor also embeds the impact of relevant human cognitive factors, such as memory and recency, and their complex interactions with the video content being viewed. We evaluated the proposed model on three different video databases and attained standout QoE prediction performance.
Deal, Shanley B; Alseidi, Adnan A
2017-12-01
Online videos are among the most common resources for case preparation. Using crowd sourcing, we evaluated the relationship between operative quality and viewing characteristics of online laparoscopic cholecystectomy videos. We edited 160 online videos of laparoscopic cholecystectomy to 60 seconds or less. Crowd workers (CW) rated videos using Global Objective Assessment of Laparoscopic Skills (GOALS), the critical view of safety (CVS) criteria, and assigned overall pass/fail ratings if CVS was achieved; linear mixed effects models derived average ratings. Views, likes, dislikes, subscribers, and country were recorded for subset analysis of YouTube videos. Spearman correlation coefficient (SCC) assessed correlation between performance measures. One video (0.06%) achieved a passing CVS score of ≥5; 23%, ≥4; 44%, ≥3; 79%, ≥2; and 100% ≥1. Pass/fail ratings correlated to CVS, SCC 0.95 (p < 0.001) and to GOALS, SCC 0.79 (p < 0.001). YouTube videos (n = 139) with higher views, likes, or subscribers did not correlate with better quality. The average CVS and GOALS scores were no different for videos with >20,000 views (22%) compared with those with <20,000 (78%). There is an incredibly low frequency of CVS and average GOALS technical performance in frequently used online surgical videos of LC. Favorable characteristics, such as number of views or likes, do not translate to higher quality. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.
Impact of different cloud deployments on real-time video applications for mobile video cloud users
NASA Astrophysics Data System (ADS)
Khan, Kashif A.; Wang, Qi; Luo, Chunbo; Wang, Xinheng; Grecos, Christos
2015-02-01
The latest trend to access mobile cloud services through wireless network connectivity has amplified globally among both entrepreneurs and home end users. Although existing public cloud service vendors such as Google, Microsoft Azure etc. are providing on-demand cloud services with affordable cost for mobile users, there are still a number of challenges to achieve high-quality mobile cloud based video applications, especially due to the bandwidth-constrained and errorprone mobile network connectivity, which is the communication bottleneck for end-to-end video delivery. In addition, existing accessible clouds networking architectures are different in term of their implementation, services, resources, storage, pricing, support and so on, and these differences have varied impact on the performance of cloud-based real-time video applications. Nevertheless, these challenges and impacts have not been thoroughly investigated in the literature. In our previous work, we have implemented a mobile cloud network model that integrates localized and decentralized cloudlets (mini-clouds) and wireless mesh networks. In this paper, we deploy a real-time framework consisting of various existing Internet cloud networking architectures (Google Cloud, Microsoft Azure and Eucalyptus Cloud) and a cloudlet based on Ubuntu Enterprise Cloud over wireless mesh networking technology for mobile cloud end users. It is noted that the increasing trend to access real-time video streaming over HTTP/HTTPS is gaining popularity among both research and industrial communities to leverage the existing web services and HTTP infrastructure in the Internet. To study the performance under different deployments using different public and private cloud service providers, we employ real-time video streaming over the HTTP/HTTPS standard, and conduct experimental evaluation and in-depth comparative analysis of the impact of different deployments on the quality of service for mobile video cloud users. Empirical results are presented and discussed to quantify and explain the different impacts resulted from various cloud deployments, video application and wireless/mobile network setting, and user mobility. Additionally, this paper analyses the advantages, disadvantages, limitations and optimization techniques in various cloud networking deployments, in particular the cloudlet approach compared with the Internet cloud approach, with recommendations of optimized deployments highlighted. Finally, federated clouds and inter-cloud collaboration challenges and opportunities are discussed in the context of supporting real-time video applications for mobile users.
NASA Astrophysics Data System (ADS)
Al Hadhrami, Tawfik; Nightingale, James M.; Wang, Qi; Grecos, Christos
2014-05-01
In emergency situations, the ability to remotely monitor unfolding events using high-quality video feeds will significantly improve the incident commander's understanding of the situation and thereby aids effective decision making. This paper presents a novel, adaptive video monitoring system for emergency situations where the normal communications network infrastructure has been severely impaired or is no longer operational. The proposed scheme, operating over a rapidly deployable wireless mesh network, supports real-time video feeds between first responders, forward operating bases and primary command and control centers. Video feeds captured on portable devices carried by first responders and by static visual sensors are encoded in H.264/SVC, the scalable extension to H.264/AVC, allowing efficient, standard-based temporal, spatial, and quality scalability of the video. A three-tier video delivery system is proposed, which balances the need to avoid overuse of mesh nodes with the operational requirements of the emergency management team. In the first tier, the video feeds are delivered at a low spatial and temporal resolution employing only the base layer of the H.264/SVC video stream. Routing in this mode is designed to employ all nodes across the entire mesh network. In the second tier, whenever operational considerations require that commanders or operators focus on a particular video feed, a `fidelity control' mechanism at the monitoring station sends control messages to the routing and scheduling agents in the mesh network, which increase the quality of the received picture using SNR scalability while conserving bandwidth by maintaining a low frame rate. In this mode, routing decisions are based on reliable packet delivery with the most reliable routes being used to deliver the base and lower enhancement layers; as fidelity is increased and more scalable layers are transmitted they will be assigned to routes in descending order of reliability. The third tier of video delivery transmits a high-quality video stream including all available scalable layers using the most reliable routes through the mesh network ensuring the highest possible video quality. The proposed scheme is implemented in a proven simulator, and the performance of the proposed system is numerically evaluated through extensive simulations. We further present an in-depth analysis of the proposed solutions and potential approaches towards supporting high-quality visual communications in such a demanding context.
NASA Astrophysics Data System (ADS)
Chen, Zhenzhong; Han, Junwei; Ngan, King Ngi
2005-10-01
MPEG-4 treats a scene as a composition of several objects or so-called video object planes (VOPs) that are separately encoded and decoded. Such a flexible video coding framework makes it possible to code different video object with different distortion scale. It is necessary to analyze the priority of the video objects according to its semantic importance, intrinsic properties and psycho-visual characteristics such that the bit budget can be distributed properly to video objects to improve the perceptual quality of the compressed video. This paper aims to provide an automatic video object priority definition method based on object-level visual attention model and further propose an optimization framework for video object bit allocation. One significant contribution of this work is that the human visual system characteristics are incorporated into the video coding optimization process. Another advantage is that the priority of the video object can be obtained automatically instead of fixing weighting factors before encoding or relying on the user interactivity. To evaluate the performance of the proposed approach, we compare it with traditional verification model bit allocation and the optimal multiple video object bit allocation algorithms. Comparing with traditional bit allocation algorithms, the objective quality of the object with higher priority is significantly improved under this framework. These results demonstrate the usefulness of this unsupervised subjective quality lifting framework.
YouTube videos as a source of medical information during the Ebola hemorrhagic fever epidemic.
Nagpal, Sajan Jiv Singh; Karimianpour, Ahmadreza; Mukhija, Dhruvika; Mohan, Diwakar; Brateanu, Andrei
2015-01-01
The content and quality of medical information available on video sharing websites such as YouTube is not known. We analyzed the source and quality of medical information about Ebola hemorrhagic fever (EHF) disseminated on YouTube and the video characteristics that influence viewer behavior. An inquiry for the search term 'Ebola' was made on YouTube. The first 100 results were arranged in decreasing order of "relevance" using the default YouTube algorithm. Videos 1-50 and 51-100 were allocated to a high relevance (HR), and a low relevance (LR) video group, respectively. Multivariable logistic regression models were used to assess the predictors of a video being included in the HR vs. LR groups. Fourteen videos were excluded because they were parodies, songs or stand-up comedies (n = 11), not in English (n = 2) or a remaining part of a previous video (n = 1). Two scales, the video information and quality and index and the medical information and content index (MICI) assessed the overall quality, and the medical content of the videos, respectively. There were no videos from hospitals or academic medical centers. Videos in the HR group had a higher median number of views (186,705 vs. 43,796, p < 0.001), more 'likes' (1119 vs. 224, p < 0.001), channel subscriptions (208 vs. 32, p < 0.001), and 'shares' (519 vs. 98, p < 0.001). Multivariable logistic regression showed that only the 'clinical symptoms' component of the MICI scale was associated with a higher likelihood of a video being included in the HR vs. LR group.(OR 1.86, 95 % CI 1.06-3.28, p = 0.03). YouTube videos presenting clinical symptoms of infectious diseases during epidemics are more likely to be included in the HR group and influence viewers behavior.
Objective video presentation QoE predictor for smart adaptive video streaming
NASA Astrophysics Data System (ADS)
Wang, Zhou; Zeng, Kai; Rehman, Abdul; Yeganeh, Hojatollah; Wang, Shiqi
2015-09-01
How to deliver videos to consumers over the network for optimal quality-of-experience (QoE) has been the central goal of modern video delivery services. Surprisingly, regardless of the large volume of videos being delivered everyday through various systems attempting to improve visual QoE, the actual QoE of end consumers is not properly assessed, not to say using QoE as the key factor in making critical decisions at the video hosting, network and receiving sites. Real-world video streaming systems typically use bitrate as the main video presentation quality indicator, but using the same bitrate to encode different video content could result in drastically different visual QoE, which is further affected by the display device and viewing condition of each individual consumer who receives the video. To correct this, we have to put QoE back to the driver's seat and redesign the video delivery systems. To achieve this goal, a major challenge is to find an objective video presentation QoE predictor that is accurate, fast, easy-to-use, display device adaptive, and provides meaningful QoE predictions across resolution and content. We propose to use the newly developed SSIMplus index (https://ece.uwaterloo.ca/~z70wang/research/ssimplus/) for this role. We demonstrate that based on SSIMplus, one can develop a smart adaptive video streaming strategy that leads to much smoother visual QoE impossible to achieve using existing adaptive bitrate video streaming approaches. Furthermore, SSIMplus finds many more applications, in live and file-based quality monitoring, in benchmarking video encoders and transcoders, and in guiding network resource allocations.
Surgical videos online: a survey of prominent sources and future trends.
Dinscore, Amanda; Andres, Amy
2010-01-01
This article determines the extent of the online availability and quality of surgical videos for the educational benefit of the surgical community. A comprehensive survey was performed that compared a number of online sites providing surgical videos according to their content, production quality, authority, audience, navigability, and other features. Methods for evaluating video content are discussed as well as possible future directions and emerging trends. Surgical videos are a valuable tool for demonstrating and teaching surgical technique and, despite room for growth in this area, advances in streaming video technology have made providing and accessing these resources easier than ever before.
Golai, Shruti; Patil, Sandya Devi; Baali, Praveen; Kumar, Hemanth
2015-01-01
Introduction The aim of the study was to assess the correlation between the oral health status, oral health related quality of life and the evaluations of their smiles as assessed by the children, their parents, and through measurements of the children’s videotaped smiles and compare the smiling patterns in children suffering from untreated traumatic injuries to anterior teeth and control group. Materials and Methods Fifty eight children of the age 5–15 years of both sexes were selected for the study and categorized into experimental group and control group. The experimental group consisted of 29 children with untreated trauma to one or more anterior teeth while the control group consisted of 29 children with good oral health. Oral examination of all children was done to include in study groups. Children and parents participating in the study responded to two separate Oral Health Related Quality of Life questionnaires for children and parents respectively. The children were asked to watch a funny cartoon show and a video was made while the children watched the show. The video was cropped into still images at 25 predetermined points. Width and openness of the children’s mouth and number of teeth shown were measured during the taped sessions to assess the children’s video–based smiling patterns. Results The children’s self evaluation scores had statistically significant correlation with their smiling patterns, the number of traumatized teeth and the parental assessment of their children’s oral health. Children with trauma to anterior teeth had more impacts on their smiling pattern compared to control group. Conclusion Children suffering from trauma to anterior teeth had more effects on the emotions, the self confidence and social interaction than children without any traumatic injury. PMID:26266209
Quality of YouTube TM videos on dental implants.
Abukaraky, A; Hamdan, A-A; Ameera, M-N; Nasief, M; Hassona, Y
2018-07-01
Patients search YouTube for health-care information. To examine what YouTube offers patients seeking information on dental implants, and to evaluate the quality of provided information. A systematic search of YouTube for videos containing information on dental implants was performed using the key words Dental implant and Tooth replacement. Videos were examined by two senior Oral and Maxillofacial Surgery residents who were trained and calibrated to perform the search. Initial assessment was performed to exclude non- English language videos, duplicate videos, conference lectures, and irrelevant videos. Included videos were analyzed with regard to demographics and content's usefulness. Information for patients available from the American Academy of Implant Dentistry, European Association of Osseointegration, and British Society of Restorative Dentistry were used for benchmarking. A total of 117 videos were analyzed. The most commonly discussed topics were related to procedures involved in dental implantology (76.1%, n=89), and to the indications for dental implants (58.1%, n=78). The mean usefulness score of videos was poor (6.02 ±4.7 [range 0-21]), and misleading content was common (30.1% of videos); mainly in topics related to prognosis and maintenance of dental implants. Most videos (83.1%, n=97) failed to mention the source of information presented in the video or where to find more about dental implants. Information about dental implants on YouTube is limited in quality and quantity. YouTube videos can have a potentially important role in modulating patients attitude and treatment decision regarding dental implants.
Failure of anthropometry as a facial identification technique using high-quality photographs.
Kleinberg, Krista F; Vanezis, Peter; Burton, A Mike
2007-07-01
Anthropometry can be used in certain circumstances to facilitate comparison of a photograph of a suspect with that of the potential offender from surveillance footage. Experimental research was conducted to determine whether anthropometry has a place in forensic practice in confirming the identity of a suspect from a surveillance video. We examined an existing database of photographic lineups, where one video image was compared against 10 photographs, which has previously been used in psychological research. Target (1) and test (10) photos were of high quality, although taken with a different camera. The anthropometric landmarks of right and left ectocanthions, nasion, and stomion were chosen, and proportions and angle values between these landmarks were measured to compare target with test photos. Results indicate that these measurements failed to accurately identify targets. There was also no indication that any of the landmarks made a better comparison than another. It was concluded that, for these landmarks, this method does not generate the consistent results necessary for use as evidence in a court of law.
NASA Astrophysics Data System (ADS)
Boisson, Guillaume; Kerbiriou, Paul; Drazic, Valter; Bureller, Olivier; Sabater, Neus; Schubert, Arno
2014-03-01
Generating depth maps along with video streams is valuable for Cinema and Television production. Thanks to the improvements of depth acquisition systems, the challenge of fusion between depth sensing and disparity estimation is widely investigated in computer vision. This paper presents a new framework for generating depth maps from a rig made of a professional camera with two satellite cameras and a Kinect device. A new disparity-based calibration method is proposed so that registered Kinect depth samples become perfectly consistent with disparities estimated between rectified views. Also, a new hierarchical fusion approach is proposed for combining on the flow depth sensing and disparity estimation in order to circumvent their respective weaknesses. Depth is determined by minimizing a global energy criterion that takes into account the matching reliability and the consistency with the Kinect input. Thus generated depth maps are relevant both in uniform and textured areas, without holes due to occlusions or structured light shadows. Our GPU implementation reaches 20fps for generating quarter-pel accurate HD720p depth maps along with main view, which is close to real-time performances for video applications. The estimated depth is high quality and suitable for 3D reconstruction or virtual view synthesis.
2016-01-01
Purpose: The quality of problem representation is critical for developing students’ problem-solving abilities in problem-based learning (PBL). This study investigates preclinical students’ experience with standardized patients (SPs) as a problem representation method compared to using video cases in PBL. Methods: A cohort of 99 second-year preclinical students from Inje University College of Medicine (IUCM) responded to a Likert scale questionnaire on their learning experiences after they had experienced both video cases and SPs in PBL. The questionnaire consisted of 14 items with eight subcategories: problem identification, hypothesis generation, motivation, collaborative learning, reflective thinking, authenticity, patient-doctor communication, and attitude toward patients. Results: The results reveal that using SPs led to the preclinical students having significantly positive experiences in boosting patient-doctor communication skills; the perceived authenticity of their clinical situations; development of proper attitudes toward patients; and motivation, reflective thinking, and collaborative learning when compared to using video cases. The SPs also provided more challenges than the video cases during problem identification and hypotheses generation. Conclusion: SPs are more effective than video cases in delivering higher levels of authenticity in clinical problems for PBL. The interaction with SPs engages preclinical students in deeper thinking and discussion; growth of communication skills; development of proper attitudes toward patients; and motivation. Considering the higher cost of SPs compared with video cases, SPs could be used most advantageously during the preclinical period in the IUCM curriculum. PMID:26923094
Student-Built Underwater Video and Data Capturing Device
NASA Astrophysics Data System (ADS)
Whitt, F.
2016-12-01
Students from Stockbridge High School Robotics Team invention is a low cost underwater video and data capturing device. This system is capable of shooting time-lapse photography and/or video for up to 3 days of video at a time. It can be used in remote locations without having to change batteries or adding additional external hard drives for data storage. The video capturing device has a unique base and mounting system which houses a pi drive and a programmable raspberry pi with a camera module. This system is powered by two 12 volt batteries, which makes it easier for users to recharge after use. Our data capturing device has the same unique base and mounting system as the underwater camera. The data capturing device consists of an Arduino and SD card shield that is capable of collecting continuous temperature and pH readings underwater. This data will then be logged onto the SD card for easy access and recording. The low cost underwater video and data capturing device can reach depths up to 100 meters while recording 36 hours of video on 1 terabyte of storage. It also features night vision infrared light capabilities. The cost to build our invention is $500. The goal of this was to provide a device that can easily be accessed by marine biologists, teachers, researchers and citizen scientists to capture photographic and water quality data in marine environments over extended periods of time.
Scalable video transmission over Rayleigh fading channels using LDPC codes
NASA Astrophysics Data System (ADS)
Bansal, Manu; Kondi, Lisimachos P.
2005-03-01
In this paper, we investigate an important problem of efficiently utilizing the available resources for video transmission over wireless channels while maintaining a good decoded video quality and resilience to channel impairments. Our system consists of the video codec based on 3-D set partitioning in hierarchical trees (3-D SPIHT) algorithm and employs two different schemes using low-density parity check (LDPC) codes for channel error protection. The first method uses the serial concatenation of the constant-rate LDPC code and rate-compatible punctured convolutional (RCPC) codes. Cyclic redundancy check (CRC) is used to detect transmission errors. In the other scheme, we use the product code structure consisting of a constant rate LDPC/CRC code across the rows of the `blocks' of source data and an erasure-correction systematic Reed-Solomon (RS) code as the column code. In both the schemes introduced here, we use fixed-length source packets protected with unequal forward error correction coding ensuring a strictly decreasing protection across the bitstream. A Rayleigh flat-fading channel with additive white Gaussian noise (AWGN) is modeled for the transmission. The rate-distortion optimization algorithm is developed and carried out for the selection of source coding and channel coding rates using Lagrangian optimization. The experimental results demonstrate the effectiveness of this system under different wireless channel conditions and both the proposed methods (LDPC+RCPC/CRC and RS+LDPC/CRC) outperform the more conventional schemes such as those employing RCPC/CRC.
Interactional Quality Depicted in Infant and Toddler Videos: Where Are the Interactions?
ERIC Educational Resources Information Center
Fenstermacher, Susan K.; Barr, Rachel; Brey, Elizabeth; Pempek, Tiffany A.; Ryan, Maureen; Calvert, Sandra L.; Shwery, Clay E.; Linebarger, Deborah
2010-01-01
This study examined the social-emotional content and the quality of social interactions depicted in a sample of 58 DVDs marketed towards infants and toddlers. Infant-directed videos rarely used social interactions between caregiver and child or between peers to present content. Even when videos explicitly targeted social-emotional content,…
Is perception of quality more important than technical quality in patient video cases?
Roland, Damian; Matheson, David; Taub, Nick; Coats, Tim; Lakhanpaul, Monica
2015-08-13
The use of video cases to demonstrate key signs and symptoms in patients (patient video cases or PVCs) is a rapidly expanding field. The aims of this study were to evaluate whether the technical quality, or judgement of quality, of a video clip influences a paediatrician's judgment on acuity of the case and assess the relationship between perception of quality and the technical quality of a selection of video clips. Participants (12 senior consultant paediatricians attending an examination workshop) individually categorised 28 PVCs into one of 3 possible acuities and then described the quality of the image seen. The PVCs had been converted into four different technical qualities (differing bit rates ranging from excellent to low quality). Participants' assessment of quality and the actual industry standard of the PVC were independent (333 distinct observations, spearmans rho = 0.0410, p = 0.4564). Agreement between actual acuity and participants' judgement was generally good at higher acuities but moderate at medium/low acuities of illness (overall correlation 0.664). Perception of the quality of the clip was related to correct assignment of acuity regardless of the technical quality of the clip (number of obs = 330, z = 2.07, p = 0.038). It is important to benchmark PVCs prior to use in learning resources as experts may not agree on the information within, or quality of, the clip. It appears, although PVCs may be beneficial in a pedagogical context, the perception of quality of clip may be an important determinant of an expert's decision making.
Subjective Quality Assessment of Underwater Video for Scientific Applications
Moreno-Roldán, José-Miguel; Luque-Nieto, Miguel-Ángel; Poncela, Javier; Díaz-del-Río, Víctor; Otero, Pablo
2015-01-01
Underwater video services could be a key application in the better scientific knowledge of the vast oceanic resources in our planet. However, limitations in the capacity of current available technology for underwater networks (UWSNs) raise the question of the feasibility of these services. When transmitting video, the main constraints are the limited bandwidth and the high propagation delays. At the same time the service performance depends on the needs of the target group. This paper considers the problems of estimations for the Mean Opinion Score (a standard quality measure) in UWSNs based on objective methods and addresses the topic of quality assessment in potential underwater video services from a subjective point of view. The experimental design and the results of a test planned according standardized psychometric methods are presented. The subjects used in the quality assessment test were ocean scientists. Video sequences were recorded in actual exploration expeditions and were processed to simulate conditions similar to those that might be found in UWSNs. Our experimental results show how videos are considered to be useful for scientific purposes even in very low bitrate conditions. PMID:26694400
Subjective Quality Assessment of Underwater Video for Scientific Applications.
Moreno-Roldán, José-Miguel; Luque-Nieto, Miguel-Ángel; Poncela, Javier; Díaz-del-Río, Víctor; Otero, Pablo
2015-12-15
Underwater video services could be a key application in the better scientific knowledge of the vast oceanic resources in our planet. However, limitations in the capacity of current available technology for underwater networks (UWSNs) raise the question of the feasibility of these services. When transmitting video, the main constraints are the limited bandwidth and the high propagation delays. At the same time the service performance depends on the needs of the target group. This paper considers the problems of estimations for the Mean Opinion Score (a standard quality measure) in UWSNs based on objective methods and addresses the topic of quality assessment in potential underwater video services from a subjective point of view. The experimental design and the results of a test planned according standardized psychometric methods are presented. The subjects used in the quality assessment test were ocean scientists. Video sequences were recorded in actual exploration expeditions and were processed to simulate conditions similar to those that might be found in UWSNs. Our experimental results show how videos are considered to be useful for scientific purposes even in very low bitrate conditions.
Hashimoto, Daniel A; Phitayakorn, Roy; Fernandez-del Castillo, Carlos; Meireles, Ozanan
2016-01-01
The goal of telementoring is to recreate face-to-face encounters with a digital presence. Open-surgery telementoring is limited by lack of surgeon's point-of-view cameras. Google Glass is a wearable computer that looks like a pair of glasses but is equipped with wireless connectivity, a camera, and viewing screen for video conferencing. This study aimed to assess the safety of using Google Glass by assessing the video quality of a telementoring session. Thirty-four (n = 34) surgeons at a single institution were surveyed and blindly compared via video captured with Google Glass versus an Apple iPhone 5 during the open cholecystectomy portion of a Whipple. Surgeons were asked to evaluate the quality of the video and its adequacy for safe use in telementoring. Thirty-four of 107 invited surgical attendings (32%) responded to the anonymous survey. A total of 50% rated the Google Glass video as fair with the other 50% rating it as bad to poor. A total of 52.9% of respondents rated the Apple iPhone video as good. A significantly greater proportion of respondents felt Google Glass video quality was inadequate for telementoring versus the Apple iPhone's (82.4 vs 26.5%, p < 0.0001). Intraclass correlation coefficient was 0.924 (95% CI 0.660-0.999, p < 0.001). While Google Glass provides a great breadth of functionality as a wearable device with two-way communication capabilities, current hardware limitations prevent its use as a telementoring device in surgery as the video quality is inadequate for safe telementoring. As the device is still in initial phases of development, future iterations or competitor devices may provide a better telementoring application for wearable devices.
YouTube and food allergy: An appraisal of the educational quality of information.
Reddy, Keerthi; Kearns, Mary; Alvarez-Arango, Santiago; Carrillo-Martin, Ismael; Cuervo-Pardo, Nathaly; Cuervo-Pardo, Lyda; Dimov, Ves; Lang, David M; Lopez-Alvarez, Sonia; Schroer, Brian; Mohan, Kaushik; Dula, Mark; Zheng, Simin; Kozinetz, Claudia; Gonzalez-Estrada, Alexei
2018-06-01
Food allergy affects an estimated 8% of children and 3% of adults in the United States. Food-allergic individuals increasingly use the web for medical information. We sought to determine the educational quality of food allergy YouTube videos. We performed a YouTube search using keywords "food allergy" and "food allergies". The 300 most viewed videos were included and analyzed for characteristics, source, and content. Source was further classified as healthcare provider, alternative medicine provider, patient, company, media, and professional society. A scoring system (FA-DQS) was created to evaluate quality (-10 to +34 points). Negative points were assigned for misleading information. Eight reviewers scored each video independently. Three hundred videos were analyzed, with a median of 6351.50 views, 19 likes, and 1 dislike. More video presenters were female (54.3%). The most common type of video source was alternative medicine provider (26.3%). Alternative treatments included the following: water fast, juicing, Ayurveda, apple cider, yoga, visualization, and sea moss. Controversial diagnostics included kinesiology, IgG testing, and pulse test. Almost half of the videos depicted a non-IgE-mediated reaction (49.0%).Videos by professional societies had the highest FA-DQS (7.27). Scores for videos by professional societies were significantly different from other sources (P < .001). There was a high degree of agreement among reviewers (ICC = 0.820; P < .001). YouTube videos on food allergy frequently recommend controversial diagnostics and commonly depict non-IgE-mediated reactions. There is a need for high-quality, evidence-based, educational videos on food allergy. © 2018 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.
Urch, Ekaterina; Taylor, Samuel A; Cody, Elizabeth; Fabricant, Peter D; Burket, Jayme C; O'Brien, Stephen J; Dines, David M; Dines, Joshua S
2016-10-01
The internet has an increasing role in both patient and physician education. While several recent studies critically appraised the quality and accuracy of web-based written information available to patients, no studies have evaluated such parameters for open-access video content designed for provider use. The primary goal of the study was to determine the accuracy of internet-based instructional videos featuring the shoulder physical examination. An assessment of quality and accuracy of said video content was performed using the basic shoulder examination as a surrogate for the "best-case scenario" due to its widely accepted components that are stable over time. Three search terms ("shoulder," "examination," and "shoulder exam") were entered into the four online video resources most commonly accessed by orthopaedic surgery residents (VuMedi, G9MD, Orthobullets, and YouTube). Videos were captured and independently reviewed by three orthopaedic surgeons. Quality and accuracy were assessed in accordance with previously published standards. Of the 39 video tutorials reviewed, 61% were rated as fair or poor. Specific maneuvers such as the Hawkins test, O'Brien sign, and Neer impingement test were accurately demonstrated in 50, 36, and 27% of videos, respectively. Inter-rater reliability was excellent (mean kappa 0.80, range 0.79-0.81). Our results suggest that information presented in open-access video tutorials featuring the physical examination of the shoulder is inconsistent. Trainee exposure to such potentially inaccurate information may have a significant impact on trainee education.
Breaking the news on mobile TV: user requirements of a popular mobile content
NASA Astrophysics Data System (ADS)
Knoche, Hendrik O.; Sasse, M. Angela
2006-02-01
This paper presents the results from three lab-based studies that investigated different ways of delivering Mobile TV News by measuring user responses to different encoding bitrates, image resolutions and text quality. All studies were carried out with participants watching News content on mobile devices, with a total of 216 participants rating the acceptability of the viewing experience. Study 1 compared the acceptability of a 15-second video clip at different video and audio encoding bit rates on a 3G phone at a resolution of 176x144 and an iPAQ PDA (240x180). Study 2 measured the acceptability of video quality of full feature news clips of 2.5 minutes which were recorded from broadcast TV, encoded at resolutions ranging from 120x90 to 240x180, and combined with different encoding bit rates and audio qualities presented on an iPAQ. Study 3 improved the legibility of the text included in the video simulating a separate text delivery. The acceptability of News' video quality was greatly reduced at a resolution of 120x90. The legibility of text was a decisive factor in the participants' assessment of the video quality. Resolutions of 168x126 and higher were substantially more acceptable when they were accompanied by optimized high quality text compared to proportionally scaled inline text. When accompanied by high quality text TV news clips were acceptable to the vast majority of participants at resolutions as small as 168x126 for video encoding bitrates of 160kbps and higher. Service designers and operators can apply this knowledge to design a cost-effective mobile TV experience.
Brain Training with Video Games in Covert Hepatic Encephalopathy.
Bajaj, Jasmohan S; Ahluwalia, Vishwadeep; Thacker, Leroy R; Fagan, Andrew; Gavis, Edith A; Lennon, Michael; Heuman, Douglas M; Fuchs, Michael; Wade, James B
2017-02-01
Despite the associated adverse outcomes, pharmacologic intervention for covert hepatic encephalopathy (CHE) is not the standard of care. We hypothesized that a video game-based rehabilitation program would improve white matter integrity and brain connectivity in the visuospatial network on brain magnetic resonance imaging (MRI), resulting in improved cognitive function in CHE subjects on measures consistent with the cognitive skill set emphasized by the two video games (e.g., IQ Boost-visual working memory, and Aim and Fire Challenge-psychomotor speed), but also generalize to thinking skills beyond the focus of the cognitive training (Hopkins verbal learning test (HVLT)-verbal learning/memory) and improve their health-related quality of life (HRQOL). The trial included three phases over 8 weeks; during the learning phase (cognitive tests administered twice over 2 weeks without intervening intervention), training phase (daily video game training for 4 weeks), and post-training phase (testing 2 weeks after the video game training ended). Thirty CHE patients completed all visits with significant daily achievement on the video games. In a subset of 13 subjects that underwent brain MRI, there was a significant decrease in fractional anisotropy, and increased radial diffusivity (suggesting axonal sprouting or increased cross-fiber formation) involving similar brain regions (i.e., corpus callosum, internal capsule, and sections of the corticospinal tract) and improvement in the visuospatial resting-state connectivity corresponding to the video game training domains. No significant corresponding improvement in HRQOL or HVLT performance was noted, but cognitive performance did transiently improve on cognitive tests similar to the video games during training. Although multimodal brain imaging changes suggest reductions in tract edema and improved neural network connectivity, this trial of video game brain training did not improve the HRQOL or produce lasting improvement in cognitive function in patients with CHE.
Misinformation is prevalent in psoriasis-related YouTube videos.
Qi, J; Trang, T; Doong, J; Kang, S; Chien, A L
2016-11-15
Background Psoriasis patients seek information online, but little is known about their interaction with YouTube. We examined the quality of content in psoriasis-related YouTube videos and investigated their interactions with viewers.Methods YouTube was searched using the term "psoriasis." Relevant videos in English were independently categorized by two reviewers as useful, misleading, or patient view (regarding experience with psoriasis). Disagreements were settled by a third reviewer. Videos were rated on a Global Quality Scale (GQS) (1=poor, 5=excellent).Results According to our reviewers, 17% of the 47 videos were useful, 21% were misleading, and 62% represented patient views. Mean GQS scores were 4.2 ± 1.3 for useful videos, 1.7 ± 0.7 for misleading videos, and 2.2 ± 1.1 for patient view videos (p<0.001). Video views per day did not differ among the categories (p=0.65), whereas useful videos had fewest "Likes" (useful: 31 ± 55, 33 misleading: 151 ± 218, patient views: 165 ± 325, p=0.06) and comments (useful: 9.8 ± 18.3, misleading: 64.1 ± 89.7, 124.9 ± 34 199.4, p=0.009).Conclusions Useful videos were highest in quality but had similar viewership as misleading and patient view videos, with lower popularity and engagement of users compared to other categories. Physicians and psoriasis patients should be aware of this pattern when pproaching YouTube as a resource.
Villafañe, Jorge Hugo; Cantero-Tellez, Raquel; Valdes, Kristin; Usuelli, Federico Giuseppe; Berjano, Pedro
2017-09-01
Conservative treatments are commonly performed therapeutic interventions for the management of carpometacarpal (CMC) joint osteoarthritis (OA). Physical and occupational therapies are starting to use video-based online content as both a patient teaching tool and a source for treatment techniques. YouTube is a popular video-sharing website that can be accessed easily. The purpose of this study was to analyze the quality of content and potential sources of bias in videos available on YouTube pertaining to thumb exercises for CMC OA. The YouTube video database was systematically searched using the search term thumb osteoarthritis and exercises from its inception to March 10, 2017. Authors independently selected videos, conducted quality assessment, and extracted results. A total of 832 videos were found using the keywords. Of these, 10 videos clearly demonstrated therapeutic exercise for the management of CMC OA. In addition, the top-ranked video found by performing a search of "views" was a video with more than 121 863 views uploaded in 2015 that lasted 12.33 minutes and scored only 2 points on the Global Score for Educational Value rating scale. Most of the videos viewed that described conservative interventions for CMC OA management have a low level of evidence to support their use. Although patients and novice hand therapists are using YouTube and other online resources, videos that are produced by expert hand therapists are scarce.
Weighted-MSE based on saliency map for assessing video quality of H.264 video streams
NASA Astrophysics Data System (ADS)
Boujut, H.; Benois-Pineau, J.; Hadar, O.; Ahmed, T.; Bonnet, P.
2011-01-01
Human vision system is very complex and has been studied for many years specifically for purposes of efficient encoding of visual, e.g. video content from digital TV. There have been physiological and psychological evidences which indicate that viewers do not pay equal attention to all exposed visual information, but only focus on certain areas known as focus of attention (FOA) or saliency regions. In this work, we propose a novel based objective quality assessment metric, for assessing the perceptual quality of decoded video sequences affected by transmission errors and packed loses. The proposed method weights the Mean Square Error (MSE), Weighted-MSE (WMSE), according to the calculated saliency map at each pixel. Our method was validated trough subjective quality experiments.
Evaluating Palliative Care Resources Available to the Public Using the Internet and Social Media.
Claudio, Celeste H; Dizon, Zoelle B; October, Tessie W
2018-01-01
Accessible information about palliative care available to the public on the Internet is growing. We do not know whether this information is consistent with the current accepted definition of palliative care. To identify resources on the Internet and social media regarding palliative care and evaluate the information conveyed. A cross-sectional study of "palliative care" search results. Top 10 Google websites, top 10 most viewed YouTube videos, and social media platforms, Facebook and Twitter, were searched. The most popular Google websites were mostly from national organizations promoting palliative care, whose definitions of palliative care consistently mention "quality of life" and "relief from symptoms and stress." None of the websites mentioned children, and 77% cited palliative care as treatment for cancer with less focus on other diseases. No personal stories were included in Google websites, while 60% of YouTube videos included personal stories. Five main themes were generated from 266 YouTube video comments analyzed. The most common theme was emotionality, of which 91% were positive statements. Facebook and Twitter were mostly used by health-care professionals and not the public. Palliative care resources are mostly positive and consistent with the current definition of palliative care. Major Internet search engines such as Google and YouTube provide valuable insight into information the public receives about palliative care. Future development of Internet resources on palliative care should consider including children and emphasizing palliative care for all life-limiting illnesses.
Hudali, Tamer; Papireddy, Muralidhar; Bhattarai, Mukul; Deckard, Alan; Hingle, Susan
2017-01-10
Hospital medicine is a relatively new specialty field, dedicated to the delivery of comprehensive medical care to hospitalized patients. YouTube is one of the most frequently used websites, offering access to a gamut of videos from self-produced to professionally made. The aim of our study was to determine the adequacy of YouTube as an effective means to define and depict the role of hospitalists. YouTube was searched on November 17, 2014, using the following search words: "hospitalist," "hospitalist definition," "what is the role of a hospitalist," "define hospitalist," and "who is a hospitalist." Videos found only in the first 10 pages of each search were included. Non-English, noneducational, and nonrelevant videos were excluded. A novel 7-point scoring tool was created by the authors based on the definition of a hospitalist adopted by the Society of Hospital Medicine. Three independent reviewers evaluated, scored, and classified the videos into high, intermediate, and low quality based on the average score. A total of 102 videos out of 855 were identified as relevant and included in the analysis. Videos uploaded by academic institutions had the highest mean score. Only 6 videos were classified as high quality, 53 as intermediate quality, and 42 as low quality, with 82.4% (84/102) of the videos scoring an average of 4 or less. Most videos found in the search of a hospitalist definition are inadequate. Leading medical organizations and academic institutions should consider producing and uploading quality videos to YouTube to help patients and their families better understand the roles and definition of the hospitalist. ©Tamer Hudali, Muralidhar Papireddy, Mukul Bhattarai, Alan Deckard, Susan Hingle. Originally published in the Interactive Journal of Medical Research (http://www.i-jmr.org/), 10.01.2017.
The Educational Efficacy of Distinct Information Delivery Systems in Modified Video Games
ERIC Educational Resources Information Center
Moshirnia, Andrew; Israel, Maya
2010-01-01
Despite the increasing popularity of many commercial video games, this popularity is not shared by educational video games. Modified video games, however, can bridge the gap in quality between commercial and education video games by embedding educational content into popular commercial video games. This study examined how different information…
Design considerations for computationally constrained two-way real-time video communication
NASA Astrophysics Data System (ADS)
Bivolarski, Lazar M.; Saunders, Steven E.; Ralston, John D.
2009-08-01
Today's video codecs have evolved primarily to meet the requirements of the motion picture and broadcast industries, where high-complexity studio encoding can be utilized to create highly-compressed master copies that are then broadcast one-way for playback using less-expensive, lower-complexity consumer devices for decoding and playback. Related standards activities have largely ignored the computational complexity and bandwidth constraints of wireless or Internet based real-time video communications using devices such as cell phones or webcams. Telecommunications industry efforts to develop and standardize video codecs for applications such as video telephony and video conferencing have not yielded image size, quality, and frame-rate performance that match today's consumer expectations and market requirements for Internet and mobile video services. This paper reviews the constraints and the corresponding video codec requirements imposed by real-time, 2-way mobile video applications. Several promising elements of a new mobile video codec architecture are identified, and more comprehensive computational complexity metrics and video quality metrics are proposed in order to support the design, testing, and standardization of these new mobile video codecs.
Quality models for audiovisual streaming
NASA Astrophysics Data System (ADS)
Thang, Truong Cong; Kim, Young Suk; Kim, Cheon Seog; Ro, Yong Man
2006-01-01
Quality is an essential factor in multimedia communication, especially in compression and adaptation. Quality metrics can be divided into three categories: within-modality quality, cross-modality quality, and multi-modality quality. Most research has so far focused on within-modality quality. Moreover, quality is normally just considered from the perceptual perspective. In practice, content may be drastically adapted, even converted to another modality. In this case, we should consider the quality from semantic perspective as well. In this work, we investigate the multi-modality quality from the semantic perspective. To model the semantic quality, we apply the concept of "conceptual graph", which consists of semantic nodes and relations between the nodes. As an typical of multi-modality example, we focus on audiovisual streaming service. Specifically, we evaluate the amount of information conveyed by a audiovisual content where both video and audio channels may be strongly degraded, even audio are converted to text. In the experiments, we also consider the perceptual quality model of audiovisual content, so as to see the difference with semantic quality model.
High-quality and small-capacity e-learning video featuring lecturer-superimposing PC screen images
NASA Astrophysics Data System (ADS)
Nomura, Yoshihiko; Murakami, Michinobu; Sakamoto, Ryota; Sugiura, Tokuhiro; Matsui, Hirokazu; Kato, Norihiko
2006-10-01
Information processing and communication technology are progressing quickly, and are prevailing throughout various technological fields. Therefore, the development of such technology should respond to the needs for improvement of quality in the e-learning education system. The authors propose a new video-image compression processing system that ingeniously employs the features of the lecturing scene. While dynamic lecturing scene is shot by a digital video camera, screen images are electronically stored by a PC screen image capturing software in relatively long period at a practical class. Then, a lecturer and a lecture stick are extracted from the digital video images by pattern recognition techniques, and the extracted images are superimposed on the appropriate PC screen images by off-line processing. Thus, we have succeeded to create a high-quality and small-capacity (HQ/SC) video-on-demand educational content featuring the advantages: the high quality of image sharpness, the small electronic file capacity, and the realistic lecturer motion.
Objective Video Quality Assessment Based on Machine Learning for Underwater Scientific Applications
Moreno-Roldán, José-Miguel; Luque-Nieto, Miguel-Ángel; Poncela, Javier; Otero, Pablo
2017-01-01
Video services are meant to be a fundamental tool in the development of oceanic research. The current technology for underwater networks (UWNs) imposes strong constraints in the transmission capacity since only a severely limited bitrate is available. However, previous studies have shown that the quality of experience (QoE) is enough for ocean scientists to consider the service useful, although the perceived quality can change significantly for small ranges of variation of video parameters. In this context, objective video quality assessment (VQA) methods become essential in network planning and real time quality adaptation fields. This paper presents two specialized models for objective VQA, designed to match the special requirements of UWNs. The models are built upon machine learning techniques and trained with actual user data gathered from subjective tests. Our performance analysis shows how both of them can successfully estimate quality as a mean opinion score (MOS) value and, for the second model, even compute a distribution function for user scores. PMID:28333123
13 point video tape quality guidelines
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gaunt, R.
1997-05-01
Until high definition television (ATV) arrives, in the U.S. we must still contend with the National Television Systems Committee (NTSC) video standard (or PAL or SECAM-depending on your country). NTSC, a 40-year old standard designed for transmission of color video camera images over a small bandwidth, is not well suited for the sharp, full-color images that todays computers are capable of producing. PAL and SECAM also suffers from many of NTSC`s problems, but to varying degrees. Video professionals, when working with computer graphic (CG) images, use two monitors: a computer monitor for producing CGs and an NTSC monitor to viewmore » how a CG will look on video. More often than not, the NTSC image will differ significantly from the CG image, and outputting it to NTSC as an artist works enables the him or her to see the images as others will see it. Below are thirteen guidelines designed to increase the quality of computer graphics recorded onto video tape. Viewing your work in NTSC and attempting to follow the below tips will enable you to create higher quality videos. No video is perfect, so don`t expect to abide by every guideline every time.« less
The study of surgical image quality evaluation system by subjective quality factor method
NASA Astrophysics Data System (ADS)
Zhang, Jian J.; Xuan, Jason R.; Yang, Xirong; Yu, Honggang; Koullick, Edouard
2016-03-01
GreenLightTM procedure is an effective and economical way of treatment of benign prostate hyperplasia (BPH); there are almost a million of patients treated with GreenLightTM worldwide. During the surgical procedure, the surgeon or physician will rely on the monitoring video system to survey and confirm the surgical progress. There are a few obstructions that could greatly affect the image quality of the monitoring video, like laser glare by the tissue and body fluid, air bubbles and debris generated by tissue evaporation, and bleeding, just to name a few. In order to improve the physician's visual experience of a laser surgical procedure, the system performance parameter related to image quality needs to be well defined. However, since image quality is the integrated set of perceptions of the overall degree of excellence of an image, or in other words, image quality is the perceptually weighted combination of significant attributes (contrast, graininess …) of an image when considered in its marketplace or application, there is no standard definition on overall image or video quality especially for the no-reference case (without a standard chart as reference). In this study, Subjective Quality Factor (SQF) and acutance are used for no-reference image quality evaluation. Basic image quality parameters, like sharpness, color accuracy, size of obstruction and transmission of obstruction, are used as subparameter to define the rating scale for image quality evaluation or comparison. Sample image groups were evaluated by human observers according to the rating scale. Surveys of physician groups were also conducted with lab generated sample videos. The study shows that human subjective perception is a trustworthy way of image quality evaluation. More systematic investigation on the relationship between video quality and image quality of each frame will be conducted as a future study.
Region-of-interest determination and bit-rate conversion for H.264 video transcoding
NASA Astrophysics Data System (ADS)
Huang, Shu-Fen; Chen, Mei-Juan; Tai, Kuang-Han; Li, Mian-Shiuan
2013-12-01
This paper presents a video bit-rate transcoder for baseline profile in H.264/AVC standard to fit the available channel bandwidth for the client when transmitting video bit-streams via communication channels. To maintain visual quality for low bit-rate video efficiently, this study analyzes the decoded information in the transcoder and proposes a Bayesian theorem-based region-of-interest (ROI) determination algorithm. In addition, a curve fitting scheme is employed to find the models of video bit-rate conversion. The transcoded video will conform to the target bit-rate by re-quantization according to our proposed models. After integrating the ROI detection method and the bit-rate transcoding models, the ROI-based transcoder allocates more coding bits to ROI regions and reduces the complexity of the re-encoding procedure for non-ROI regions. Hence, it not only keeps the coding quality but improves the efficiency of the video transcoding for low target bit-rates and makes the real-time transcoding more practical. Experimental results show that the proposed framework gets significantly better visual quality.
Scollato, A; Perrini, P; Benedetto, N; Di Lorenzo, N
2007-06-01
We propose an easy-to-construct digital video editing system ideal to produce video documentation and still images. A digital video editing system applicable to many video sources in the operating room is described in detail. The proposed system has proved easy to use and permits one to obtain videography quickly and easily. Mixing different streams of video input from all the devices in use in the operating room, the application of filters and effects produces a final, professional end-product. Recording on a DVD provides an inexpensive, portable and easy-to-use medium to store or re-edit or tape at a later time. From stored videography it is easy to extract high-quality, still images useful for teaching, presentations and publications. In conclusion digital videography and still photography can easily be recorded by the proposed system, producing high-quality video recording. The use of firewire ports provides good compatibility with next-generation hardware and software. The high standard of quality makes the proposed system one of the lowest priced products available today.
Cardiac ultrasonography over 4G wireless networks using a tele-operated robot
Panayides, Andreas S.; Jossif, Antonis P.; Christoforou, Eftychios G.; Vieyres, Pierre; Novales, Cyril; Voskarides, Sotos; Pattichis, Constantinos S.
2016-01-01
This Letter proposes an end-to-end mobile tele-echography platform using a portable robot for remote cardiac ultrasonography. Performance evaluation investigates the capacity of long-term evolution (LTE) wireless networks to facilitate responsive robot tele-manipulation and real-time ultrasound video streaming that qualifies for clinical practice. Within this context, a thorough video coding standards comparison for cardiac ultrasound applications is performed, using a data set of ten ultrasound videos. Both objective and subjective (clinical) video quality assessment demonstrate that H.264/AVC and high efficiency video coding standards can achieve diagnostically-lossless video quality at bitrates well within the LTE supported data rates. Most importantly, reduced latencies experienced throughout the live tele-echography sessions allow the medical expert to remotely operate the robot in a responsive manner, using the wirelessly communicated cardiac ultrasound video to reach a diagnosis. Based on preliminary results documented in this Letter, the proposed robotised tele-echography platform can provide for reliable, remote diagnosis, achieving comparable quality of experience levels with in-hospital ultrasound examinations. PMID:27733929
Comparing Audio and Video Data for Rating Communication
Williams, Kristine; Herman, Ruth; Bontempo, Daniel
2013-01-01
Video recording has become increasingly popular in nursing research, adding rich nonverbal, contextual, and behavioral information. However, benefits of video over audio data have not been well established. We compared communication ratings of audio versus video data using the Emotional Tone Rating Scale. Twenty raters watched video clips of nursing care and rated staff communication on 12 descriptors that reflect dimensions of person-centered and controlling communication. Another group rated audio-only versions of the same clips. Interrater consistency was high within each group with ICC (2,1) for audio = .91, and video = .94. Interrater consistency for both groups combined was also high with ICC (2,1) for audio and video = .95. Communication ratings using audio and video data were highly correlated. The value of video being superior to audio recorded data should be evaluated in designing studies evaluating nursing care. PMID:23579475
Popular on YouTube: a critical appraisal of the educational quality of information regarding asthma.
Gonzalez-Estrada, Alexei; Cuervo-Pardo, Lyda; Ghosh, Bitan; Smith, Martin; Pazheri, Foussena; Zell, Katrina; Wang, Xiao-Feng; Lang, David M
2015-01-01
Asthma affects >300 million people globally, including 25 million in the United States. Patients with asthma frequently use the Internet as a source of information. YouTube is one of the three most popular Web sites. To determine the educational quality of YouTube videos for asthma. We performed a YouTube search by using the keyword "asthma." The 200 most frequently viewed relevant videos were included in the study. Asthma videos were analyzed for characteristics, source, and content. Source was further classified as asthma health care provider, other health care provider, patient, pharmaceutical company, and professional society and/or media. A scoring system was created to evaluate quality (-10 to 30 points). Negative points were assigned for misleading information. Two hundred videos were analyzed, with a median of 18,073.5 views, 31.5 likes, and 2 dislikes, which spanned a median of 172 seconds. More video presenters were male (60.5%). The most common type of video source was other health care providers (34.5%). The most common video content was alternative treatments (38.0%), including live-fish ingestion; reflexology; acupressure and/or acupuncture; Ayurveda; yoga; raw food, vegan, gluten-free diets; marijuana; Buteyko breathing; and salt therapy. Scores for videos supplied by asthma health care providers were statistically significantly different from other sources (p < 0.001) and had the highest average score (9.91). YouTube videos of asthma were frequently viewed but were a poor source of accurate health care information. Videos by asthma health care providers were rated highest in quality. The allergy/immunology community has a clear opportunity to enhance the value of educational material on YouTube.
Khandelwal, Aditi; Devine, Luke A; Otremba, Mirek
2017-07-01
Many instructional materials for point-of-care ultrasound (US)-guided procedures exist; however, their quality is unknown. This study assessed widely available educational videos for point-of-care US-guided procedures relevant to internal medicine: central venous catheterization, thoracentesis, and paracentesis. We searched Ovid MEDLINE, YouTube, and Google to identify videos for point-of-care US-guided paracentesis, thoracentesis, and central venous catheterization. Videos were evaluated with a 5-point scale assessing the global educational value and a checklist based on consensus guidelines for competencies in point-of-care US-guided procedures. For point-of-care US-guided central venous catheterization, 12 videos were found, with an average global educational value score ± SD of 4.5 ± 0.7. Indications to abort the procedure were discussed in only 3 videos. Five videos described the indications and contraindications for performing central venous catheterization. For point-of-care US-guided thoracentesis, 8 videos were identified, with an average global educational value score of 4.0 ± 0.9. Only one video discussed indications to abort the procedure, and 3 videos discussed sterile technique. For point-of-care US-guided paracentesis, 7 videos were included, with an average global educational value score of 4.1 ± 0.9. Only 1 video discussed indications to abort the procedure, and 2 described the location of the inferior epigastric artery. The 27 videos reviewed contained good-quality general instruction. However, we noted a lack of safety-related information in most of the available videos. Further development of resources is required to teach internal medicine trainees skills that focus on the safety of point-of-care US guidance. © 2017 by the American Institute of Ultrasound in Medicine.
Real-time video streaming in mobile cloud over heterogeneous wireless networks
NASA Astrophysics Data System (ADS)
Abdallah-Saleh, Saleh; Wang, Qi; Grecos, Christos
2012-06-01
Recently, the concept of Mobile Cloud Computing (MCC) has been proposed to offload the resource requirements in computational capabilities, storage and security from mobile devices into the cloud. Internet video applications such as real-time streaming are expected to be ubiquitously deployed and supported over the cloud for mobile users, who typically encounter a range of wireless networks of diverse radio access technologies during their roaming. However, real-time video streaming for mobile cloud users across heterogeneous wireless networks presents multiple challenges. The network-layer quality of service (QoS) provision to support high-quality mobile video delivery in this demanding scenario remains an open research question, and this in turn affects the application-level visual quality and impedes mobile users' perceived quality of experience (QoE). In this paper, we devise a framework to support real-time video streaming in this new mobile video networking paradigm and evaluate the performance of the proposed framework empirically through a lab-based yet realistic testing platform. One particular issue we focus on is the effect of users' mobility on the QoS of video streaming over the cloud. We design and implement a hybrid platform comprising of a test-bed and an emulator, on which our concept of mobile cloud computing, video streaming and heterogeneous wireless networks are implemented and integrated to allow the testing of our framework. As representative heterogeneous wireless networks, the popular WLAN (Wi-Fi) and MAN (WiMAX) networks are incorporated in order to evaluate effects of handovers between these different radio access technologies. The H.264/AVC (Advanced Video Coding) standard is employed for real-time video streaming from a server to mobile users (client nodes) in the networks. Mobility support is introduced to enable continuous streaming experience for a mobile user across the heterogeneous wireless network. Real-time video stream packets are captured for analytical purposes on the mobile user node. Experimental results are obtained and analysed. Future work is identified towards further improvement of the current design and implementation. With this new mobile video networking concept and paradigm implemented and evaluated, results and observations obtained from this study would form the basis of a more in-depth, comprehensive understanding of various challenges and opportunities in supporting high-quality real-time video streaming in mobile cloud over heterogeneous wireless networks.
Home Telehealth Video Conferencing: Perceptions and Performance
Morris, Greg; Pech, Joanne; Rechter, Stuart; Carati, Colin; Kidd, Michael R
2015-01-01
Background The Flinders Telehealth in the Home trial (FTH trial), conducted in South Australia, was an action research initiative to test and evaluate the inclusion of telehealth services and broadband access technologies for palliative care patients living in the community and home-based rehabilitation services for the elderly at home. Telehealth services at home were supported by video conferencing between a therapist, nurse or doctor, and a patient using the iPad tablet. Objective The aims of this study are to identify which technical factors influence the quality of video conferencing in the home setting and to assess the impact of these factors on the clinical perceptions and acceptance of video conferencing for health care delivery into the home. Finally, we aim to identify any relationships between technical factors and clinical acceptance of this technology. Methods An action research process developed several quantitative and qualitative procedures during the FTH trial to investigate technology performance and users perceptions of the technology including measurements of signal power, data transmission throughput, objective assessment of user perceptions of videoconference quality, and questionnaires administered to clinical users. Results The effectiveness of telehealth was judged by clinicians as equivalent to or better than a home visit on 192 (71.6%, 192/268) occasions, and clinicians rated the experience of conducting a telehealth session compared with a home visit as equivalent or better in 90.3% (489/540) of the sessions. It was found that the quality of video conferencing when using a third generation mobile data service (3G) in comparison to broadband fiber-based services was concerning as 23.5% (220/936) of the calls failed during the telehealth sessions. The experimental field tests indicated that video conferencing audio and video quality was worse when using mobile data services compared with fiber to the home services. As well, statistically significant associations were found between audio/video quality and patient comfort with the technology as well as the clinician ratings for effectiveness of telehealth. Conclusions These results showed that the quality of video conferencing when using 3G-based mobile data services instead of broadband fiber-based services was less due to failed calls, audio/ video jitter, and video pixilation during the telehealth sessions. Nevertheless, clinicians felt able to deliver effective services to patients at home using 3G-based mobile data services. PMID:26381104
YouTube as a source of information for obstructive sleep apnea.
Singh, Sameer K; Liu, Stanley; Capasso, Robson; Kern, Robert C; Gouveia, Christopher J
Assess the quality of information on obstructive sleep apnea (OSA) presented on YouTube for patients. "Obstructive sleep apnea" was entered into the YouTube search. Two independent reviewers categorized and analyzed videos utilizing a customized scoring-system along with search position, likes, and views. Forty-eight videos were analyzed. Most were educational (52.1%). Educational and news videos had significantly higher scores, but had no significant differences in search position, likes/day, or views/day. Most videos mentioned positive airway pressure (65%), and nearly half (44%) mentioned mandibular devices in the management of OSA. Few videos discussed surgery (13%) or otolaryngology (15%). YouTube is a promising source of information for OSA patients. Educational and news videos are of highest quality. General quality measures like search position, views, and likes are not correlated with formally scored value. Sleep surgery and otolaryngologists are minimally mentioned, representing an opportunity for improvement. Copyright © 2018 Elsevier Inc. All rights reserved.
Nápoles, Anna M.; Santoyo-Olsson, Jasmine; Karliner, Leah S.; O’Brien, Helen; Gregorich, Steven E.; Pérez-Stable, Eliseo J.
2013-01-01
Language interpretation ameliorates health disparities among underserved limited English-proficient patients, yet few studies have compared clinician satisfaction with these services. Self-administered clinician post-visit surveys compared the quality of interpretation and communication, visit satisfaction, degree of patient engagement, and cultural competence of visits using untrained people acting as interpreters (ad hoc), in-person professional, or video conferencing professional interpretation for 283 visits. Adjusting for clinician and patient characteristics, the quality of interpretation of in-person and video conferencing modes were rated similarly (OR=1.79; 95% CI 0.74, 4.33). The quality of in-person (OR=5.55; 95% CI 1.50, 20.51) and video conferencing (OR=3.10; 95% CI 1.16, 8.31) were rated higher than ad hoc interpretation. Self-assessed cultural competence was better for in-person versus video conferencing interpretation (OR=2.32; 95% CI 1.11, 4.86). Video conferencing interpretation increases access without compromising quality, but cultural nuances may be better addressed by in-person interpreters. Professional interpretation is superior to ad hoc (OR=4.15; 95% CI 1.43, 12.09). PMID:20173271
Diefenbacher, Katja; Schultz, Jobst-Hendrik; Maatouk, Imad; Herrmann-Werner, Anne; Koehl-Hackert, Nadja; Herzog, Wolfgang; Nikendei, Christoph
2017-01-01
Background Standardized patients are widely used in training of medical students, both in teaching and assessment. They also frequently lead complete training sessions delivering physical examination skills without the aid of faculty teaching staff–acting as “patient instructors” (PIs). An important part of this training is their ability to provide detailed structured feedback to students which has a strong impact on their learning success. Yet, to date no study has assessed the quality of physical examination related feedback by PIs. Therefore, we conducted a randomized controlled study comparing feedback of PIs and faculty staff following a physical examination assessed by students and video assessors. Methods 14 PIs and 14 different faculty staff physicians both delivered feedback to 40 medical students that had performed a physical examination on the respective PI while the physicians observed the performance. The physical examination was rated by two independent video assessors to provide an objective performance standard (gold standard). Feedback of PI and physicians was content analyzed by two different independent video assessors based on a provided checklist and compared to the performance standard. Feedback of PIs and physicians was also rated by medical students and video assessors using a questionnaire consisting of 12 items. Results There was no statistical significant difference concerning overall matching of physician or PI feedback with gold standard ratings by video assessment (p = .219). There was also no statistical difference when focusing only on items that were classified as major key steps (p = .802), mistakes or parts that were left out during physical examination (p = .219) or mistakes in communication items (p = .517). The feedback of physicians was significantly better rated than PI feedback both by students (p = .043) as well as by video assessors (p = .034). Conclusions In summary, our study demonstrates that trained PIs are able to provide feedback of equal quantitative value to that of faculty staff physicians with regard to a physical examination performed on them. However, both the students and the video raters judged the quality of the feedback given by the physicians to be significantly better than that of the PIs. PMID:28692703
Krautter, Markus; Diefenbacher, Katja; Schultz, Jobst-Hendrik; Maatouk, Imad; Herrmann-Werner, Anne; Koehl-Hackert, Nadja; Herzog, Wolfgang; Nikendei, Christoph
2017-01-01
Standardized patients are widely used in training of medical students, both in teaching and assessment. They also frequently lead complete training sessions delivering physical examination skills without the aid of faculty teaching staff-acting as "patient instructors" (PIs). An important part of this training is their ability to provide detailed structured feedback to students which has a strong impact on their learning success. Yet, to date no study has assessed the quality of physical examination related feedback by PIs. Therefore, we conducted a randomized controlled study comparing feedback of PIs and faculty staff following a physical examination assessed by students and video assessors. 14 PIs and 14 different faculty staff physicians both delivered feedback to 40 medical students that had performed a physical examination on the respective PI while the physicians observed the performance. The physical examination was rated by two independent video assessors to provide an objective performance standard (gold standard). Feedback of PI and physicians was content analyzed by two different independent video assessors based on a provided checklist and compared to the performance standard. Feedback of PIs and physicians was also rated by medical students and video assessors using a questionnaire consisting of 12 items. There was no statistical significant difference concerning overall matching of physician or PI feedback with gold standard ratings by video assessment (p = .219). There was also no statistical difference when focusing only on items that were classified as major key steps (p = .802), mistakes or parts that were left out during physical examination (p = .219) or mistakes in communication items (p = .517). The feedback of physicians was significantly better rated than PI feedback both by students (p = .043) as well as by video assessors (p = .034). In summary, our study demonstrates that trained PIs are able to provide feedback of equal quantitative value to that of faculty staff physicians with regard to a physical examination performed on them. However, both the students and the video raters judged the quality of the feedback given by the physicians to be significantly better than that of the PIs.
Predefined Redundant Dictionary for Effective Depth Maps Representation
NASA Astrophysics Data System (ADS)
Sebai, Dorsaf; Chaieb, Faten; Ghorbel, Faouzi
2016-01-01
The multi-view video plus depth (MVD) video format consists of two components: texture and depth map, where a combination of these components enables a receiver to generate arbitrary virtual views. However, MVD presents a very voluminous video format that requires a compression process for storage and especially for transmission. Conventional codecs are perfectly efficient for texture images compression but not for intrinsic depth maps properties. Depth images indeed are characterized by areas of smoothly varying grey levels separated by sharp discontinuities at the position of object boundaries. Preserving these characteristics is important to enable high quality view synthesis at the receiver side. In this paper, sparse representation of depth maps is discussed. It is shown that a significant gain in sparsity is achieved when particular mixed dictionaries are used for approximating these types of images with greedy selection strategies. Experiments are conducted to confirm the effectiveness at producing sparse representations, and competitiveness, with respect to candidate state-of-art dictionaries. Finally, the resulting method is shown to be effective for depth maps compression and represents an advantage over the ongoing 3D high efficiency video coding compression standard, particularly at medium and high bitrates.
Nuutinen, Mikko; Virtanen, Toni; Rummukainen, Olli; Häkkinen, Jukka
2016-03-01
This article presents VQone, a graphical experiment builder, written as a MATLAB toolbox, developed for image and video quality ratings. VQone contains the main elements needed for the subjective image and video quality rating process. This includes building and conducting experiments and data analysis. All functions can be controlled through graphical user interfaces. The experiment builder includes many standardized image and video quality rating methods. Moreover, it enables the creation of new methods or modified versions from standard methods. VQone is distributed free of charge under the terms of the GNU general public license and allows code modifications to be made so that the program's functions can be adjusted according to a user's requirements. VQone is available for download from the project page (http://www.helsinki.fi/psychology/groups/visualcognition/).
NASA Astrophysics Data System (ADS)
Ndiaye, Maty; Quinquis, Catherine; Larabi, Mohamed Chaker; Le Lay, Gwenael; Saadane, Hakim; Perrine, Clency
2014-01-01
During the last decade, the important advances and widespread availability of mobile technology (operating systems, GPUs, terminal resolution and so on) have encouraged a fast development of voice and video services like video-calling. While multimedia services have largely grown on mobile devices, the generated increase of data consumption is leading to the saturation of mobile networks. In order to provide data with high bit-rates and maintain performance as close as possible to traditional networks, the 3GPP (The 3rd Generation Partnership Project) worked on a high performance standard for mobile called Long Term Evolution (LTE). In this paper, we aim at expressing recommendations related to audio and video media profiles (selection of audio and video codecs, bit-rates, frame-rates, audio and video formats) for a typical video-calling services held over LTE/4G mobile networks. These profiles are defined according to targeted devices (smartphones, tablets), so as to ensure the best possible quality of experience (QoE). Obtained results indicate that for a CIF format (352 x 288 pixels) which is usually used for smartphones, the VP8 codec provides a better image quality than the H.264 codec for low bitrates (from 128 to 384 kbps). However sequences with high motion, H.264 in slow mode is preferred. Regarding audio, better results are globally achieved using wideband codecs offering good quality except for opus codec (at 12.2 kbps).
Content-based management service for medical videos.
Mendi, Engin; Bayrak, Coskun; Cecen, Songul; Ermisoglu, Emre
2013-01-01
Development of health information technology has had a dramatic impact to improve the efficiency and quality of medical care. Developing interoperable health information systems for healthcare providers has the potential to improve the quality and equitability of patient-centered healthcare. In this article, we describe an automated content-based medical video analysis and management service that provides convenience and ease in accessing the relevant medical video content without sequential scanning. The system facilitates effective temporal video segmentation and content-based visual information retrieval that enable a more reliable understanding of medical video content. The system is implemented as a Web- and mobile-based service and has the potential to offer a knowledge-sharing platform for the purpose of efficient medical video content access.
New Integrated Video and Graphics Technology: Digital Video Interactive.
ERIC Educational Resources Information Center
Optical Information Systems, 1987
1987-01-01
Describes digital video interactive (DVI), a new technology which combines the interactivity of the graphics capabilities in personal computers with the realism of high-quality motion video and multitrack audio in an all-digital integrated system. (MES)
Gauthier, Lynne V; Kane, Chelsea; Borstad, Alexandra; Strahl, Nancy; Uswatte, Gitendra; Taub, Edward; Morris, David; Hall, Alli; Arakelian, Melissa; Mark, Victor
2017-06-08
Constraint-Induced Movement therapy (CI therapy) is shown to reduce disability, increase use of the more affected arm/hand, and promote brain plasticity for individuals with upper extremity hemiparesis post-stroke. Randomized controlled trials consistently demonstrate that CI therapy is superior to other rehabilitation paradigms, yet it is available to only a small minority of the estimated 1.2 million chronic stroke survivors with upper extremity disability. The current study aims to establish the comparative effectiveness of a novel, patient-centered approach to rehabilitation utilizing newly developed, inexpensive, and commercially available gaming technology to disseminate CI therapy to underserved individuals. Video game delivery of CI therapy will be compared against traditional clinic-based CI therapy and standard upper extremity rehabilitation. Additionally, individual factors that differentially influence response to one treatment versus another will be examined. This protocol outlines a multi-site, randomized controlled trial with parallel group design. Two hundred twenty four adults with chronic hemiparesis post-stroke will be recruited at four sites. Participants are randomized to one of four study groups: (1) traditional clinic-based CI therapy, (2) therapist-as-consultant video game CI therapy, (3) therapist-as-consultant video game CI therapy with additional therapist contact via telerehabilitation/video consultation, and (4) standard upper extremity rehabilitation. After 6-month follow-up, individuals assigned to the standard upper extremity rehabilitation condition crossover to stand-alone video game CI therapy preceded by a therapist consultation. All interventions are delivered over a period of three weeks. Primary outcome measures include motor improvement as measured by the Wolf Motor Function Test (WMFT), quality of arm use for daily activities as measured by Motor Activity Log (MAL), and quality of life as measured by the Quality of Life in Neurological Disorders (NeuroQOL). This multi-site RCT is designed to determine comparative effectiveness of in-home technology-based delivery of CI therapy versus standard upper extremity rehabilitation and in-clinic CI therapy. The study design also enables evaluation of the effect of therapist contact time on treatment outcomes within a therapist-as-consultant model of gaming and technology-based rehabilitation. Clinicaltrials.gov, NCT02631850 .
YouTube videos as a teaching tool and patient resource for infantile spasms.
Fat, Mary Jane Lim; Doja, Asif; Barrowman, Nick; Sell, Erick
2011-07-01
The purpose of this study was to assess YouTube videos for their efficacy as a patient resource for infantile spasms. Videos were searched using the terms infantile spasm, spasm, epileptic spasm, and West syndrome. The top 25 videos under each term were selected according to set criteria. Technical quality, diagnosis of infantile spasms, and suitability as a teaching resource were assessed by 2 neurologists using the Medical Video Rating Scale. There were 5858 videos found. Of the 100 top videos, 46% did not meet selection criteria. Mean rating for technical quality was 4.0 of 5 for rater 1 and 3.9 of 5 for rater 2. Raters found 60% and 64% of videos to accurately portray infantile spasms, respectively, with significant agreement (Cohen κ coefficient = 0.75, P < .001). Ten videos were considered excellent examples (grading of 5 of 5) by at least 1 rater. YouTube may be used as an excellent patient resource for infantile spasms if guided search practices are followed.
YouTube as a Source of Information on Cervical Cancer.
Adhikari, Janak; Sharma, Priyadarshani; Arjyal, Lubina; Uprety, Dipesh
2016-04-01
Cervical cancer is the third most common cancer worldwide. Accurate information about cervical cancer to general public can lower the burden of the disease including its mortality. We aimed to look at the quality of information available in YouTube for cervical cancer. We searched YouTube (http://www.youtube.com) for videos using the keyword Cervical cancer on November 12, 2015. Videos were then analyzed for their source and content of information. We studied 172 videos using the keyword Cervical cancer on November 12, 2015. We found that there were videos describing the personal stories, risk factors, and the importance of screening. However, videos discussing all the aspects of cancers were lacking. Likewise, videos from the reputed organization were also lacking. Although there were numerous videos available in cervical cancer, videos from reputed organizations including Center for Disease Control and Prevention, American Cancer Society, and World Health Organization were lacking. We strongly believe that quality videos from such organizations via YouTube can help lower the burden of disease.
Using Video Feedback to Improve Horseback-Riding Skills
ERIC Educational Resources Information Center
Kelley, Heather; Miltenberger, Raymond G.
2016-01-01
This study used video feedback to improve the horseback-riding skills of advanced beginning riders. We focused on 3 skill sets: those used in jumping over obstacles, dressage riding on the flat, and jumping position riding on the flat. Baseline consisted of standard lesson procedures. Intervention consisted of video feedback in which a recorded…
Comparing audio and video data for rating communication.
Williams, Kristine; Herman, Ruth; Bontempo, Daniel
2013-09-01
Video recording has become increasingly popular in nursing research, adding rich nonverbal, contextual, and behavioral information. However, benefits of video over audio data have not been well established. We compared communication ratings of audio versus video data using the Emotional Tone Rating Scale. Twenty raters watched video clips of nursing care and rated staff communication on 12 descriptors that reflect dimensions of person-centered and controlling communication. Another group rated audio-only versions of the same clips. Interrater consistency was high within each group with Interclass Correlation Coefficient (ICC) (2,1) for audio .91, and video = .94. Interrater consistency for both groups combined was also high with ICC (2,1) for audio and video = .95. Communication ratings using audio and video data were highly correlated. The value of video being superior to audio-recorded data should be evaluated in designing studies evaluating nursing care.
Medical Education Videos for the World: An Analysis of Viewing Patterns for a YouTube Channel.
Tackett, Sean; Slinn, Kyle; Marshall, Tanner; Gaglani, Shiv; Waldman, Vincent; Desai, Rishi
2018-01-02
Medical education videos can enhance learning and easily integrate into common instructional methods. YouTube permits worldwide access to high-quality medical education videos; however, no studies have described the reach of medical education videos on YouTube or what topics are preferred. One year of YouTube analytics data (February 1, 2016, to January 31, 2017) was collected for a medical education-focused channel called Osmosis. Created December 20, 2015, the channel had 189 disease-focused videos by January 2017. Viewer and subscriber data were analyzed according to the World Bank's 4 income and 7 region classifications. Topic viewing was analyzed according to income level. The channel had accumulated 105,117 subscribers and 5,226,405 views for 20,153,093 minutes (38.3 years) from viewers located in 213/218 (97.7%) World Bank economies. While the number of videos increased 4.8 fold from February 2016 to January 2017, monthly views increased 50 fold and subscribers increased 117 fold. Low or middle income countries generated 2.2 million (42%) views and 53,000 (50%) subscribers, with similar view proportions across income level during the 12 months. A plurality of views (1.5 million, 29%) came from North America; Sub-Saharan Africa had the lowest number (150,000, 2.9%). Topic viewing generally corresponded to population health statistics. Medical education content on YouTube can immediately and consistently reach a global viewership with relevant content. Educators may consider posting videos to YouTube to reach a broad audience. Future work should seek to optimize assessment of learning and investigate how videos may affect patients.
Lion, K Casey; Brown, Julie C; Ebel, Beth E; Klein, Eileen J; Strelitz, Bonnie; Gutman, Colleen Kays; Hencz, Patty; Fernandez, Juan; Mangione-Smith, Rita
2015-12-01
Consistent professional interpretation improves communication with patients who have limited English proficiency. Remote modalities (telephone and video) have the potential for wide dissemination. To test the effect of telephone vs. video interpretation on communication during pediatric emergency care. Randomized trial of telephone vs. video interpretation at a free-standing, university-affiliated pediatric emergency department (ED). A convenience sample of 290 Spanish-speaking parents of pediatric ED patients with limited English proficiency were approached from February 24 through August 16, 2014, of whom 249 (85.9%) enrolled; of these, 208 (83.5%) completed the follow-up survey (91 parents in the telephone arm and 117 in the video arm). Groups did not differ significantly by consent or survey completion rate, ED factors (eg, ED crowding), child factors (eg, triage level, medical complexity), or parent factors (eg, birth country, income). Investigators were blinded to the interpretation modality during outcome ascertainment. Intention-to-treat data were analyzed August 25 to October 20, 2014. Telephone or video interpretation for the ED visit, randomized by day. Parents were surveyed 1 to 7 days after the ED visit to assess communication and interpretation quality, frequency of lapses in interpreter use, and ability to name the child's diagnosis. Two blinded reviewers compared parent-reported and medical record-abstracted diagnoses and classified parent-reported diagnoses as correct, incorrect, or vague. Among 208 parents who completed the survey, those in the video arm were more likely to name the child's diagnosis correctly than those in the telephone arm (85 of 114 [74.6%] vs. 52 of 87 [59.8%]; P = .03) and less likely to report frequent lapses in interpreter use (2 of 117 [1.7%] vs. 7 of 91 [7.7%]; P = .04). No differences were found between the video and telephone arms in parent-reported quality of communication (101 of 116 [87.1%] vs. 74 of 89 [83.1%]; P = .43) or interpretation (58 of 116 [50.0%] vs. 42 of 89 [47.2%]; P = .69). Video interpretation was more costly (per-patient mean [SD] cost, $61 [$36] vs. $31 [$20]; P < .001). Parent-reported adherence to the assigned modality was higher for the video arm (106 of 114 [93.0%] vs .68 of 86 [79.1%]; P = .004). Families with limited English proficiency who received video interpretation were more likely to correctly name the child's diagnosis and had fewer lapses in interpreter use. Use of video interpretation shows promise for improving communication and patient care in this population. clinicaltrials.gov Identifier: NCT01986179.
Bi, Sheng; Zeng, Xiao; Tang, Xin; Qin, Shujia; Lai, King Wai Chiu
2016-01-01
Compressive sensing (CS) theory has opened up new paths for the development of signal processing applications. Based on this theory, a novel single pixel camera architecture has been introduced to overcome the current limitations and challenges of traditional focal plane arrays. However, video quality based on this method is limited by existing acquisition and recovery methods, and the method also suffers from being time-consuming. In this paper, a multi-frame motion estimation algorithm is proposed in CS video to enhance the video quality. The proposed algorithm uses multiple frames to implement motion estimation. Experimental results show that using multi-frame motion estimation can improve the quality of recovered videos. To further reduce the motion estimation time, a block match algorithm is used to process motion estimation. Experiments demonstrate that using the block match algorithm can reduce motion estimation time by 30%. PMID:26950127
Evaluation of Skybox Video and Still Image products
NASA Astrophysics Data System (ADS)
d'Angelo, P.; Kuschk, G.; Reinartz, P.
2014-11-01
The SkySat-1 satellite lauched by Skybox Imaging on November 21 in 2013 opens a new chapter in civilian earth observation as it is the first civilian satellite to image a target in high definition panchromatic video for up to 90 seconds. The small satellite with a mass of 100 kg carries a telescope with 3 frame sensors. Two products are available: Panchromatic video with a resolution of around 1 meter and a frame size of 2560 × 1080 pixels at 30 frames per second. Additionally, the satellite can collect still imagery with a swath of 8 km in the panchromatic band, and multispectral images with 4 bands. Using super-resolution techniques, sub-meter accuracy is reached for the still imagery. The paper provides an overview of the satellite design and imaging products. The still imagery product consists of 3 stripes of frame images with a footprint of approximately 2.6 × 1.1 km. Using bundle block adjustment, the frames are registered, and their accuracy is evaluated. Image quality of the panchromatic, multispectral and pansharpened products are evaluated. The video product used in this evaluation consists of a 60 second gazing acquisition of Las Vegas. A DSM is generated by dense stereo matching. Multiple techniques such as pairwise matching or multi image matching are used and compared. As no ground truth height reference model is availble to the authors, comparisons on flat surface and compare differently matched DSMs are performed. Additionally, visual inspection of DSM and DSM profiles show a detailed reconstruction of small features and large skyscrapers.
NASA Astrophysics Data System (ADS)
Boumehrez, Farouk; Brai, Radhia; Doghmane, Noureddine; Mansouri, Khaled
2018-01-01
Recently, video streaming has attracted much attention and interest due to its capability to process and transmit large data. We propose a quality of experience (QoE) model relying on high efficiency video coding (HEVC) encoder adaptation scheme, in turn based on the multiple description coding (MDC) for video streaming. The main contributions of the paper are (1) a performance evaluation of the new and emerging video coding standard HEVC/H.265, which is based on the variation of quantization parameter (QP) values depending on different video contents to deduce their influence on the sequence to be transmitted, (2) QoE support multimedia applications in wireless networks are investigated, so we inspect the packet loss impact on the QoE of transmitted video sequences, (3) HEVC encoder parameter adaptation scheme based on MDC is modeled with the encoder parameter and objective QoE model. A comparative study revealed that the proposed MDC approach is effective for improving the transmission with a peak signal-to-noise ratio (PSNR) gain of about 2 to 3 dB. Results show that a good choice of QP value can compensate for transmission channel effects and improve received video quality, although HEVC/H.265 is also sensitive to packet loss. The obtained results show the efficiency of our proposed method in terms of PSNR and mean-opinion-score.
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-22
... Registration for ``Healthy Young America Video Contest'' AGENCY: Office of the Secretary, Assistant Secretary...-sponsoring the ``Healthy Young America'' Video Contest with two primary goals: First, directly reaching the uninsured population through video views and votes; and second, the production of high-quality videos that...
Desktop Video Productions. ICEM Guidelines Publications No. 6.
ERIC Educational Resources Information Center
Taufour, P. A.
Desktop video consists of integrating the processing of the video signal in a microcomputer. This definition implies that desktop video can take multiple forms such as virtual editing or digital video. Desktop video, which does not imply any particular technology, has been approached in different ways in different technical fields. It remains a…
Video error concealment using block matching and frequency selective extrapolation algorithms
NASA Astrophysics Data System (ADS)
P. K., Rajani; Khaparde, Arti
2017-06-01
Error Concealment (EC) is a technique at the decoder side to hide the transmission errors. It is done by analyzing the spatial or temporal information from available video frames. It is very important to recover distorted video because they are used for various applications such as video-telephone, video-conference, TV, DVD, internet video streaming, video games etc .Retransmission-based and resilient-based methods, are also used for error removal. But these methods add delay and redundant data. So error concealment is the best option for error hiding. In this paper, the error concealment methods such as Block Matching error concealment algorithm is compared with Frequency Selective Extrapolation algorithm. Both the works are based on concealment of manually error video frames as input. The parameter used for objective quality measurement was PSNR (Peak Signal to Noise Ratio) and SSIM(Structural Similarity Index). The original video frames along with error video frames are compared with both the Error concealment algorithms. According to simulation results, Frequency Selective Extrapolation is showing better quality measures such as 48% improved PSNR and 94% increased SSIM than Block Matching Algorithm.
A Novel Approach to High Definition, High-Contrast Video Capture in Abdominal Surgery
Cosman, Peter H.; Shearer, Christopher J.; Hugh, Thomas J.; Biankin, Andrew V.; Merrett, Neil D.
2007-01-01
Objective: The aim of this study was to define the best available option for video capture of surgical procedures for educational and archival purposes, with a view to identifying methods of capturing high-quality footage and identifying common pitfalls. Summary Background Data: Several options exist for those who wish to record operative surgical techniques on video. While high-end equipment is an unnecessary expense for most surgical units, several techniques are readily available that do not require industrial-grade audiovisual recording facilities, but not all are suited to every surgical application. Methods: We surveyed and evaluated the available technology for video capture in surgery. Our evaluation included analyses of video resolution, depth of field, contrast, exposure, image stability, and frame composition, as well as considerations of cost, accessibility, utility, feasibility, and economies of scale. Results: Several video capture options were identified, and the strengths and shortcomings of each were catalogued. None of the commercially available options was deemed suitable for high-quality video capture of abdominal surgical procedures. A novel application of off-the-shelf technology was devised to address these issues. Conclusions: Excellent quality video capture of surgical procedures within deep body cavities is feasible using commonly available equipment and technology, with minimal technical difficulty. PMID:17414600
An Attention-Information-Based Spatial Adaptation Framework for Browsing Videos via Mobile Devices
NASA Astrophysics Data System (ADS)
Li, Houqiang; Wang, Yi; Chen, Chang Wen
2007-12-01
With the growing popularity of personal digital assistant devices and smart phones, more and more consumers are becoming quite enthusiastic to appreciate videos via mobile devices. However, limited display size of the mobile devices has been imposing significant barriers for users to enjoy browsing high-resolution videos. In this paper, we present an attention-information-based spatial adaptation framework to address this problem. The whole framework includes two major parts: video content generation and video adaptation system. During video compression, the attention information in video sequences will be detected using an attention model and embedded into bitstreams with proposed supplement-enhanced information (SEI) structure. Furthermore, we also develop an innovative scheme to adaptively adjust quantization parameters in order to simultaneously improve the quality of overall encoding and the quality of transcoding the attention areas. When the high-resolution bitstream is transmitted to mobile users, a fast transcoding algorithm we developed earlier will be applied to generate a new bitstream for attention areas in frames. The new low-resolution bitstream containing mostly attention information, instead of the high-resolution one, will be sent to users for display on the mobile devices. Experimental results show that the proposed spatial adaptation scheme is able to improve both subjective and objective video qualities.
Linear array of photodiodes to track a human speaker for video recording
NASA Astrophysics Data System (ADS)
DeTone, D.; Neal, H.; Lougheed, R.
2012-12-01
Communication and collaboration using stored digital media has garnered more interest by many areas of business, government and education in recent years. This is due primarily to improvements in the quality of cameras and speed of computers. An advantage of digital media is that it can serve as an effective alternative when physical interaction is not possible. Video recordings that allow for viewers to discern a presenter's facial features, lips and hand motions are more effective than videos that do not. To attain this, one must maintain a video capture in which the speaker occupies a significant portion of the captured pixels. However, camera operators are costly, and often do an imperfect job of tracking presenters in unrehearsed situations. This creates motivation for a robust, automated system that directs a video camera to follow a presenter as he or she walks anywhere in the front of a lecture hall or large conference room. Such a system is presented. The system consists of a commercial, off-the-shelf pan/tilt/zoom (PTZ) color video camera, a necklace of infrared LEDs and a linear photodiode array detector. Electronic output from the photodiode array is processed to generate the location of the LED necklace, which is worn by a human speaker. The computer controls the video camera movements to record video of the speaker. The speaker's vertical position and depth are assumed to remain relatively constant- the video camera is sent only panning (horizontal) movement commands. The LED necklace is flashed at 70Hz at a 50% duty cycle to provide noise-filtering capability. The benefit to using a photodiode array versus a standard video camera is its higher frame rate (4kHz vs. 60Hz). The higher frame rate allows for the filtering of infrared noise such as sunlight and indoor lighting-a capability absent from other tracking technologies. The system has been tested in a large lecture hall and is shown to be effective.
Colometer: a real-time quality feedback system for screening colonoscopy.
Filip, Dobromir; Gao, Xuexin; Angulo-Rodríguez, Leticia; Mintchev, Martin P; Devlin, Shane M; Rostom, Alaa; Rosen, Wayne; Andrews, Christopher N
2012-08-28
To investigate the performance of a new software-based colonoscopy quality assessment system. The software-based system employs a novel image processing algorithm which detects the levels of image clarity, withdrawal velocity, and level of the bowel preparation in a real-time fashion from live video signal. Threshold levels of image blurriness and the withdrawal velocity below which the visualization could be considered adequate have initially been determined arbitrarily by review of sample colonoscopy videos by two experienced endoscopists. Subsequently, an overall colonoscopy quality rating was computed based on the percentage of the withdrawal time with adequate visualization (scored 1-5; 1, when the percentage was 1%-20%; 2, when the percentage was 21%-40%, etc.). In order to test the proposed velocity and blurriness thresholds, screening colonoscopy withdrawal videos from a specialized ambulatory colon cancer screening center were collected, automatically processed and rated. Quality ratings on the withdrawal were compared to the insertion in the same patients. Then, 3 experienced endoscopists reviewed the collected videos in a blinded fashion and rated the overall quality of each withdrawal (scored 1-5; 1, poor; 3, average; 5, excellent) based on 3 major aspects: image quality, colon preparation, and withdrawal velocity. The automated quality ratings were compared to the averaged endoscopist quality ratings using Spearman correlation coefficient. Fourteen screening colonoscopies were assessed. Adenomatous polyps were detected in 4/14 (29%) of the collected colonoscopy video samples. As a proof of concept, the Colometer software rated colonoscope withdrawal as having better visualization than the insertion in the 10 videos which did not have any polyps (average percent time with adequate visualization: 79% ± 5% for withdrawal and 50% ± 14% for insertion, P < 0.01). Withdrawal times during which no polyps were removed ranged from 4-12 min. The median quality rating from the automated system and the reviewers was 3.45 [interquartile range (IQR), 3.1-3.68] and 3.00 (IQR, 2.33-3.67) respectively for all colonoscopy video samples. The automated rating revealed a strong correlation with the reviewer's rating (ρ coefficient= 0.65, P = 0.01). There was good correlation of the automated overall quality rating and the mean endoscopist withdrawal speed rating (Spearman r coefficient= 0.59, P = 0.03). There was no correlation of automated overall quality rating with mean endoscopists image quality rating (Spearman r coefficient= 0.41, P = 0.15). The results from a novel automated real-time colonoscopy quality feedback system strongly agreed with the endoscopists' quality assessments. Further study is required to validate this approach.
Inferring consistent functional interaction patterns from natural stimulus FMRI data
Sun, Jiehuan; Hu, Xintao; Huang, Xiu; Liu, Yang; Li, Kaiming; Li, Xiang; Han, Junwei; Guo, Lei
2014-01-01
There has been increasing interest in how the human brain responds to natural stimulus such as video watching in the neuroimaging field. Along this direction, this paper presents our effort in inferring consistent and reproducible functional interaction patterns under natural stimulus of video watching among known functional brain regions identified by task-based fMRI. Then, we applied and compared four statistical approaches, including Bayesian network modeling with searching algorithms: greedy equivalence search (GES), Peter and Clark (PC) analysis, independent multiple greedy equivalence search (IMaGES), and the commonly used Granger causality analysis (GCA), to infer consistent and reproducible functional interaction patterns among these brain regions. It is interesting that a number of reliable and consistent functional interaction patterns were identified by the GES, PC and IMaGES algorithms in different participating subjects when they watched multiple video shots of the same semantic category. These interaction patterns are meaningful given current neuroscience knowledge and are reasonably reproducible across different brains and video shots. In particular, these consistent functional interaction patterns are supported by structural connections derived from diffusion tensor imaging (DTI) data, suggesting the structural underpinnings of consistent functional interactions. Our work demonstrates that specific consistent patterns of functional interactions among relevant brain regions might reflect the brain's fundamental mechanisms of online processing and comprehension of video messages. PMID:22440644
YouTube as a source of patient information on gallstone disease.
Lee, Jun Suh; Seo, Ho Seok; Hong, Tae Ho
2014-04-14
To investigate the quality of YouTube videos on gallstone disease and to assess viewer response according to quality. A YouTube search was performed on September 18, 2013, using the keywords ''gallbladder disease'', ''gallstone disease'', and ''gallstone treatment''. Three researchers assessed the source, length, number of views, number of likes, and days since upload. The upload source was categorised as physician or hospital (PH), medical website or TV channel, commercial website (CW), or civilian. A usefulness score was devised to assess video quality and to categorise the videos into ''very useful'', ''useful'', ''slightly useful'', or ''not useful''. Videos with misleading content were categorised as ''misleading''. One hundred and thirty-one videos were analysed. Seventy-four videos (56.5%) were misleading, 36 (27.5%) were slightly useful, 15 (11.5%) were useful, three (2.3%) were very useful, and three (2.3%) were not useful. The number of mean likes (1.3 ± 1.5 vs 17.2 ± 38.0, P = 0.007) and number of views (756.3 ± 701.0 vs 8910.7 ± 17094.7, P = 0.001) were both significantly lower in the very useful group compared with the misleading group. All three very useful videos were PH videos. Among the 74 misleading videos, 64 (86.5%) were uploaded by a CW. There was no correlation between usefulness and the number of views, the number of likes, or the length. The "gallstone flush" was the method advocated most frequently by misleading videos (25.7%). More than half of the YouTube videos on gallstone disease are misleading. Credible videos uploaded by medical professionals and filtering by the staff of YouTube appear to be necessary.
The quality of video information on burn first aid available on YouTube.
Butler, Daniel P; Perry, Fiona; Shah, Zameer; Leon-Villapalos, Jorge
2013-08-01
To evaluate the clinical accuracy and delivery of information on thermal burn first aid available on the leading video-streaming website, YouTube. YouTube was searched using four separate search terms. The first 20 videos identified for each search term were included in the study if their primary focus was on thermal burn first aid. Videos were scored by two independent reviewers using a standardised scoring system and the scores totalled to give each video an overall score out of 20. A total of 47 videos were analysed. The average video score was 8.5 out of a possible 20. No videos scored full-marks. A low correlation was found between the score given by the independent reviewers and the number of views the video received per month (Spearman's rank correlation co-efficient=0.03, p=0.86). The current standard of videos covering thermal burn first aid available on YouTube is unsatisfactory. In addition to this, viewers do not appear to be drawn to videos of higher quality. Organisations involved in managing burns and providing first aid care should be encouraged to produce clear, structured videos that can be made available on leading video streaming websites. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.
Real-time Internet connections: implications for surgical decision making in laparoscopy.
Broderick, T J; Harnett, B M; Doarn, C R; Rodas, E B; Merrell, R C
2001-08-01
To determine whether a low-bandwidth Internet connection can provide adequate image quality to support remote real-time surgical consultation. Telemedicine has been used to support care at a distance through the use of expensive equipment and broadband communication links. In the past, the operating room has been an isolated environment that has been relatively inaccessible for real-time consultation. Recent technological advances have permitted videoconferencing over low-bandwidth, inexpensive Internet connections. If these connections are shown to provide adequate video quality for surgical applications, low-bandwidth telemedicine will open the operating room environment to remote real-time surgical consultation. Surgeons performing a laparoscopic cholecystectomy in Ecuador or the Dominican Republic shared real-time laparoscopic images with a panel of surgeons at the parent university through a dial-up Internet account. The connection permitted video and audio teleconferencing to support real-time consultation as well as the transmission of real-time images and store-and-forward images for observation by the consultant panel. A total of six live consultations were analyzed. In addition, paired local and remote images were "grabbed" from the video feed during these laparoscopic cholecystectomies. Nine of these paired images were then placed into a Web-based tool designed to evaluate the effect of transmission on image quality. The authors showed for the first time the ability to identify critical anatomic structures in laparoscopy over a low-bandwidth connection via the Internet. The consultant panel of surgeons correctly remotely identified biliary and arterial anatomy during six laparoscopic cholecystectomies. Within the Web-based questionnaire, 15 surgeons could not blindly distinguish the quality of local and remote laparoscopic images. Low-bandwidth, Internet-based telemedicine is inexpensive, effective, and almost ubiquitous. Use of these inexpensive, portable technologies will allow sharing of surgical procedures and decisions regardless of location. Internet telemedicine consistently supported real-time intraoperative consultation in laparoscopic surgery. The implications are broad with respect to quality improvement and diffusion of knowledge as well as for basic consultation.
Digital cinema system using JPEG2000 movie of 8-million pixel resolution
NASA Astrophysics Data System (ADS)
Fujii, Tatsuya; Nomura, Mitsuru; Shirai, Daisuke; Yamaguchi, Takahiro; Fujii, Tetsuro; Ono, Sadayasu
2003-05-01
We have developed a prototype digital cinema system that can store, transmit and display extra high quality movies of 8-million pixel resolution, using JPEG2000 coding algorithm. The image quality is 4 times better than HDTV in resolution, and enables us to replace conventional films with digital cinema archives. Using wide-area optical gigabit IP networks, cinema contents are distributed and played back as a video-on-demand (VoD) system. The system consists of three main devices, a video server, a real-time JPEG2000 decoder, and a large-venue LCD projector. All digital movie data are compressed by JPEG2000 and stored in advance. The coded streams of 300~500 Mbps can be continuously transmitted from the PC server using TCP/IP. The decoder can perform the real-time decompression at 24/48 frames per second, using 120 parallel JPEG2000 processing elements. The received streams are expanded into 4.5Gbps raw video signals. The prototype LCD projector uses 3 pieces of 3840×2048 pixel reflective LCD panels (D-ILA) to show RGB 30-bit color movies fed by the decoder. The brightness exceeds 3000 ANSI lumens for a 300-inch screen. The refresh rate is chosen to 96Hz to thoroughly eliminate flickers, while preserving compatibility to cinema movies of 24 frames per second.
Transferring of speech movements from video to 3D face space.
Pei, Yuru; Zha, Hongbin
2007-01-01
We present a novel method for transferring speech animation recorded in low quality videos to high resolution 3D face models. The basic idea is to synthesize the animated faces by an interpolation based on a small set of 3D key face shapes which span a 3D face space. The 3D key shapes are extracted by an unsupervised learning process in 2D video space to form a set of 2D visemes which are then mapped to the 3D face space. The learning process consists of two main phases: 1) Isomap-based nonlinear dimensionality reduction to embed the video speech movements into a low-dimensional manifold and 2) K-means clustering in the low-dimensional space to extract 2D key viseme frames. Our main contribution is that we use the Isomap-based learning method to extract intrinsic geometry of the speech video space and thus to make it possible to define the 3D key viseme shapes. To do so, we need only to capture a limited number of 3D key face models by using a general 3D scanner. Moreover, we also develop a skull movement recovery method based on simple anatomical structures to enhance 3D realism in local mouth movements. Experimental results show that our method can achieve realistic 3D animation effects with a small number of 3D key face models.
PIZZARO: Forensic analysis and restoration of image and video data.
Kamenicky, Jan; Bartos, Michal; Flusser, Jan; Mahdian, Babak; Kotera, Jan; Novozamsky, Adam; Saic, Stanislav; Sroubek, Filip; Sorel, Michal; Zita, Ales; Zitova, Barbara; Sima, Zdenek; Svarc, Petr; Horinek, Jan
2016-07-01
This paper introduces a set of methods for image and video forensic analysis. They were designed to help to assess image and video credibility and origin and to restore and increase image quality by diminishing unwanted blur, noise, and other possible artifacts. The motivation came from the best practices used in the criminal investigation utilizing images and/or videos. The determination of the image source, the verification of the image content, and image restoration were identified as the most important issues of which automation can facilitate criminalists work. Novel theoretical results complemented with existing approaches (LCD re-capture detection and denoising) were implemented in the PIZZARO software tool, which consists of the image processing functionality as well as of reporting and archiving functions to ensure the repeatability of image analysis procedures and thus fulfills formal aspects of the image/video analysis work. Comparison of new proposed methods with the state of the art approaches is shown. Real use cases are presented, which illustrate the functionality of the developed methods and demonstrate their applicability in different situations. The use cases as well as the method design were solved in tight cooperation of scientists from the Institute of Criminalistics, National Drug Headquarters of the Criminal Police and Investigation Service of the Police of the Czech Republic, and image processing experts from the Czech Academy of Sciences. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Ho, Chien-Peng; Yu, Jen-Yu; Lee, Suh-Yin
2011-12-01
Recent advances in modern television systems have had profound consequences for the scalability, stability, and quality of transmitted digital data signals. This is of particular significance for peer-to-peer (P2P) video-on-demand (VoD) related platforms, faced with an immediate and growing demand for reliable service delivery. In response to demands for high-quality video, the key objectives in the construction of the proposed framework were user satisfaction with perceived video quality and the effective utilization of available resources on P2P VoD networks. This study developed a peer-based promoter to support online advertising in P2P VoD networks based on an estimation of video distortion prior to the replication of data stream chunks. The proposed technology enables the recovery of lost video using replicated stream chunks in real time. Load balance is achieved by adjusting the replication level of each candidate group according to the degree-of-distortion, thereby enabling a significant reduction in server load and increased scalability in the P2P VoD system. This approach also promotes the use of advertising as an efficient tool for commercial promotion. Results indicate that the proposed system efficiently satisfies the given fault tolerances.
NASA Astrophysics Data System (ADS)
Le, Minh Tuan; Nguyen, Congdu; Yoon, Dae-Il; Jung, Eun Ku; Jia, Jie; Kim, Hae-Kwang
2007-12-01
In this paper, we propose a method of 3D graphics to video encoding and streaming that are embedded into a remote interactive 3D visualization system for rapidly representing a 3D scene on mobile devices without having to download it from the server. In particular, a 3D graphics to video framework is presented that increases the visual quality of regions of interest (ROI) of the video by performing more bit allocation to ROI during H.264 video encoding. The ROI are identified by projection 3D objects to a 2D plane during rasterization. The system offers users to navigate the 3D scene and interact with objects of interests for querying their descriptions. We developed an adaptive media streaming server that can provide an adaptive video stream in term of object-based quality to the client according to the user's preferences and the variation of network bandwidth. Results show that by doing ROI mode selection, PSNR of test sample slightly change while visual quality of objects increases evidently.
Pillai, Ajish; Menon, Radha; Oustecky, David; Ahmad, Asyia
2017-07-24
Quality of bowel preparation and patient knowledge remains a major barrier for completing colorectal cancer screening. Few studies have tested unique ways to impact patient understanding centering on interactive computer programs, pictures, and brochures. Two studies explored instructional videos but focused on patient compliance and anxiety as endpoints. Furthermore, excessive video length and content may limit their impact on a broad patient population. No study so far has studied a video's impact on preparation quality and patient understanding of the colonoscopy procedure. We conducted a single blinded prospective study of inner city patients presenting for a first time screening colonoscopy. During their initial visit patients were randomized to watch an instructional colonoscopy video or a video discussing gastroesophageal reflux disease (GERD). All patients watched a 6 minutes long video with the same spokesperson, completed a demographic questionnaire (Supplemental Digital Content 1, http://links.lww.com/JCG/A352) and were enrolled only if screened within 30 days of their visit. On the day of the colonoscopy, patients completed a 14 question quiz of their knowledge. Blinded endoscopist graded patient preparations based on the Ottawa scale. All authors had access to the study data and reviewed and approved the final manuscript. Among the 104 subjects enrolled in the study, 56 were in the colonoscopy video group, 48 were in GERD video group, and 12 were excluded. Overall, 48% were male and 52% female; 90% of patients had less than a high school education, 76% were African American, and 67% used a 4 L split-dose preparation. There were no differences between either video group with regard to any of the above categories. Comparisons between the 2 groups revealed that the colonoscopy video group had significantly better Ottawa bowel preparation score (4.77 vs. 6.85; P=0.01) than the GERD video group. The colonoscopy video group also had less-inadequate repeat bowel preparations versus the GERD video group (9% vs. 23%; P<0.01). The overall score on the knowledge questionnaire (Supplemental Digital Content 1, http://links.lww.com/JCG/A352) was significantly higher in the colonoscopy video group as compared with the GERD video group (12.77 vs. 11.08; P<0.001. In all patients the overall quiz score positively correlated with preparation quality (odds ratio, 2.31; confidence interval, 1.35-3.94; P<0.001). Our unique population represented an overwhelmingly under-educated (85% had a high school education or less) and minority group (76% African American). They are one of the most at risk of having multiple barriers such as comprehension and reading difficulties resulting in poor preparation examinations and no shows to procedures. Our instructional video proved to be high yield in this population. The patients assigned to watch the colonoscopy video showed a significant increase in "excellent" grade adequate bowel preparation quality by >23% and a significant decrease in "inadequate" bowel preparations by almost 50%. Our study proves that an educational video can improve both comprehension with regard to all aspects of colonoscopy. ClinicalTrials.gov number, NCT02906969.
Real-time demonstration hardware for enhanced DPCM video compression algorithm
NASA Technical Reports Server (NTRS)
Bizon, Thomas P.; Whyte, Wayne A., Jr.; Marcopoli, Vincent R.
1992-01-01
The lack of available wideband digital links as well as the complexity of implementation of bandwidth efficient digital video CODECs (encoder/decoder) has worked to keep the cost of digital television transmission too high to compete with analog methods. Terrestrial and satellite video service providers, however, are now recognizing the potential gains that digital video compression offers and are proposing to incorporate compression systems to increase the number of available program channels. NASA is similarly recognizing the benefits of and trend toward digital video compression techniques for transmission of high quality video from space and therefore, has developed a digital television bandwidth compression algorithm to process standard National Television Systems Committee (NTSC) composite color television signals. The algorithm is based on differential pulse code modulation (DPCM), but additionally utilizes a non-adaptive predictor, non-uniform quantizer and multilevel Huffman coder to reduce the data rate substantially below that achievable with straight DPCM. The non-adaptive predictor and multilevel Huffman coder combine to set this technique apart from other DPCM encoding algorithms. All processing is done on a intra-field basis to prevent motion degradation and minimize hardware complexity. Computer simulations have shown the algorithm will produce broadcast quality reconstructed video at an average transmission rate of 1.8 bits/pixel. Hardware implementation of the DPCM circuit, non-adaptive predictor and non-uniform quantizer has been completed, providing realtime demonstration of the image quality at full video rates. Video sampling/reconstruction circuits have also been constructed to accomplish the analog video processing necessary for the real-time demonstration. Performance results for the completed hardware compare favorably with simulation results. Hardware implementation of the multilevel Huffman encoder/decoder is currently under development along with implementation of a buffer control algorithm to accommodate the variable data rate output of the multilevel Huffman encoder. A video CODEC of this type could be used to compress NTSC color television signals where high quality reconstruction is desirable (e.g., Space Station video transmission, transmission direct-to-the-home via direct broadcast satellite systems or cable television distribution to system headends and direct-to-the-home).
HealthTrust: a social network approach for retrieving online health videos.
Fernandez-Luque, Luis; Karlsen, Randi; Melton, Genevieve B
2012-01-31
Social media are becoming mainstream in the health domain. Despite the large volume of accurate and trustworthy health information available on social media platforms, finding good-quality health information can be difficult. Misleading health information can often be popular (eg, antivaccination videos) and therefore highly rated by general search engines. We believe that community wisdom about the quality of health information can be harnessed to help create tools for retrieving good-quality social media content. To explore approaches for extracting metrics about authoritativeness in online health communities and how these metrics positively correlate with the quality of the content. We designed a metric, called HealthTrust, that estimates the trustworthiness of social media content (eg, blog posts or videos) in a health community. The HealthTrust metric calculates reputation in an online health community based on link analysis. We used the metric to retrieve YouTube videos and channels about diabetes. In two different experiments, health consumers provided 427 ratings of 17 videos and professionals gave 162 ratings of 23 videos. In addition, two professionals reviewed 30 diabetes channels. HealthTrust may be used for retrieving online videos on diabetes, since it performed better than YouTube Search in most cases. Overall, of 20 potential channels, HealthTrust's filtering allowed only 3 bad channels (15%) versus 8 (40%) on the YouTube list. Misleading and graphic videos (eg, featuring amputations) were more commonly found by YouTube Search than by searches based on HealthTrust. However, some videos from trusted sources had low HealthTrust scores, mostly from general health content providers, and therefore not highly connected in the diabetes community. When comparing video ratings from our reviewers, we found that HealthTrust achieved a positive and statistically significant correlation with professionals (Pearson r₁₀ = .65, P = .02) and a trend toward significance with health consumers (r₇ = .65, P = .06) with videos on hemoglobinA(1c), but it did not perform as well with diabetic foot videos. The trust-based metric HealthTrust showed promising results when used to retrieve diabetes content from YouTube. Our research indicates that social network analysis may be used to identify trustworthy social media in health communities.
Two-Stream Transformer Networks for Video-based Face Alignment.
Liu, Hao; Lu, Jiwen; Feng, Jianjiang; Zhou, Jie
2017-08-01
In this paper, we propose a two-stream transformer networks (TSTN) approach for video-based face alignment. Unlike conventional image-based face alignment approaches which cannot explicitly model the temporal dependency in videos and motivated by the fact that consistent movements of facial landmarks usually occur across consecutive frames, our TSTN aims to capture the complementary information of both the spatial appearance on still frames and the temporal consistency information across frames. To achieve this, we develop a two-stream architecture, which decomposes the video-based face alignment into spatial and temporal streams accordingly. Specifically, the spatial stream aims to transform the facial image to the landmark positions by preserving the holistic facial shape structure. Accordingly, the temporal stream encodes the video input as active appearance codes, where the temporal consistency information across frames is captured to help shape refinements. Experimental results on the benchmarking video-based face alignment datasets show very competitive performance of our method in comparisons to the state-of-the-arts.
Educational quality of YouTube videos on knee arthrocentesis.
Fischer, Jonas; Geurts, Jeroen; Valderrabano, Victor; Hügle, Thomas
2013-10-01
Knee arthrocentesis is a commonly performed diagnostic and therapeutic procedure in rheumatology and orthopedic surgery. Classic teaching of arthrocentesis skills relies on hands-on practice under supervision. Video-based online teaching is an increasingly utilized educational tool in higher and clinical education. YouTube is a popular video-sharing Web site that can be accessed as a teaching source. The objective of this study was to assess the educational value of YouTube videos on knee arthrocentesis posted by health professionals and institutions during the period from 2008 to 2012. The YouTube video database was systematically searched using 5 search terms related to knee arthrocentesis. Two independent clinical reviewers assessed videos for procedural technique and educational value using a 5-point global score, ranging from 1 = poor quality to 5 = excellent educational quality. As validated international guidelines are lacking, we used the guidelines of the Swiss Society of Rheumatology as criterion standard for the procedure. Of more than thousand findings, 13 videos met the inclusion criteria. Of those, 2 contained additional animated video material: one was purely animated, and one was a check list. The average length was 3.31 ± 2.28 minutes. The most popular video had 1388 hits per month. Our mean global score for educational value was 3.1 ± 1.0. Eight videos (62 %) were considered useful for teaching purposes. Use of a "no-touch" procedure, meaning that once disinfected the skin remains untouched before needle penetration, was present in all videos. Six videos (46%) demonstrated full sterile conditions. There was no clear preference of a medial (n = 8) versus lateral (n = 5) approach. A discreet number of YouTube videos on knee arthrocentesis appeared to be suitable for application in a Web-based format for medical students, fellows, and residents. The low-average mean global score for overall educational value suggests an improvement of future video-based instructional materials on YouTube would be necessary before regular use for teaching could be recommended.
In the Public Interest: The Benefits of High Quality Child Care. [Videotape].
ERIC Educational Resources Information Center
Toronto Univ. (Ontario). Centre for Urban and Community Studies.
Noting that, in Canada, 10,000 child care programs serve children and families of diverse cultural and socioeconomic backgrounds, this video examines the characteristics and benefits of high quality programs. The 22-minute video first cites two reasons why quality child care is a current issue: the increasing number of women in the workforce and…
Using Digital Videos to Enhance Teacher Preparation
ERIC Educational Resources Information Center
Dymond, Stacy K.; Bentz, Johnell L.
2006-01-01
The technology to produce high quality, digital videos is widely available, yet its use in teacher preparation remains largely overlooked. A digital video library was created to augment instruction in a special education methods course for preservice elementary education teachers. The videos illustrated effective strategies for working with…
Huang, Chiung-Yu; Chang, En-Ting; Hsieh, Yuan-Mei; Lai, Hui-Ling
2017-10-01
The present study aimed to compare the effects of music and music video interventions on objective and subjective sleep quality in adults with sleep disturbances. A randomized controlled trial was performed on 71 adults who were recruited from the outpatient department of a hospital with 1100 beds and randomly assigned to the control, music, and music video groups. During the 4 test days (Days 2-5), for 30min before nocturnal sleep, the music group listened to Buddhist music and the music video group watched Buddhist music videos. They were instructed to not listen/watch to the music/MV on the first night (pretest, Day 1) and the final night (Day 6). The control group received no intervention. Sleep was assessed using a one-channel electroencephalography machine in their homes and self-reported questionnaires. The music and music video interventions had no effect on any objective sleep parameters, as measured using electroencephalography. However, the music group had significantly longer subjective total sleep time than the music video group did (Wald χ 2 =6.23, p=0.04). Our study results increase knowledge regarding music interventions for sleep quality in adults with sleep disturbances. This study suggested that more research is required to strengthen the scientific knowledge of the effects of music intervention on sleep quality in adults with sleep disturbances. (ISRCTN94971645). Copyright © 2017 Elsevier Ltd. All rights reserved.
Digital CODEC for real-time processing of broadcast quality video signals at 1.8 bits/pixel
NASA Technical Reports Server (NTRS)
Shalkhauser, Mary JO; Whyte, Wayne A., Jr.
1989-01-01
Advances in very large-scale integration and recent work in the field of bandwidth efficient digital modulation techniques have combined to make digital video processing technically feasible and potentially cost competitive for broadcast quality television transmission. A hardware implementation was developed for a DPCM-based digital television bandwidth compression algorithm which processes standard NTSC composite color television signals and produces broadcast quality video in real time at an average of 1.8 bits/pixel. The data compression algorithm and the hardware implementation of the CODEC are described, and performance results are provided.
Digital CODEC for real-time processing of broadcast quality video signals at 1.8 bits/pixel
NASA Technical Reports Server (NTRS)
Shalkhauser, Mary JO; Whyte, Wayne A.
1991-01-01
Advances in very large scale integration and recent work in the field of bandwidth efficient digital modulation techniques have combined to make digital video processing technically feasible an potentially cost competitive for broadcast quality television transmission. A hardware implementation was developed for DPCM (differential pulse code midulation)-based digital television bandwidth compression algorithm which processes standard NTSC composite color television signals and produces broadcast quality video in real time at an average of 1.8 bits/pixel. The data compression algorithm and the hardware implementation of the codec are described, and performance results are provided.
Wang, Yan; Yang, Yue-Chang; Lan, Dan-Mei; Wu, Hui -Juan; Zhao, Zhong-Xin
2017-05-01
Sleep disturbance is common in Parkinson's disease (PD) and negatively impacts quality of life. There is little data on how dopamine agonists influence nocturnal sleep in PD, particularly in sleep laboratory data to measure sleep parameters and their changes objectively. The goal of this open-label study was to objectively evaluate the effect of rotigotine on sleep in PD patients by video-polysomnographic methods. A total of 25 PD patients with complaints of nocturnal sleep impairment were enrolled. The sleep quality before and after stable rotigotine therapy was evaluated subjectively through questionnaire assessments and objectively measured by video-polysomnographic methods. The Parkinsonism, depression, anxiety, and quality of life of PD patients were also evaluated through questionnaire assessments. At the end of rotigotine treatment, the PD daytime functioning, motor performance, depression, subjective quality of sleep, and the quality of life improved. Video-polysomnographic analysis showed that the sleep efficiency and stage N1% were increased, while the sleep latency, wake after sleep onset, and the periodic leg movements in sleep index were decreased after rotigotine treatment. Video-polysomnographic analysis confirmed the subjective improvement of sleep after rotigotine treatment. This observation suggests that in PD rotigotine is a treatment option for patients complaining from sleep disturbances.
Assessment of "YouTube" Content for Distal Radius Fracture Immobilization.
Addar, Abdullah; Marwan, Yousef; Algarni, Nizar; Berry, Gregory
Distal radius fractures (DRFs) are the most common orthopedic fractures, with >70% of cases treated by closed immobilization using a short arm cast or a sugar tong splint. However, inadequate immobilization is a risk factor for loss of reduction requiring repeat reduction or surgical treatment. Therefore, education of clinical skills for appropriate immobilization of DRFs is important. With the increasing use of web-based information by medical learners, our aim was to assess the quality and quantity of videos regarding closed immobilization of DRFs on YouTube. Retrospective review of YouTube videos on distal radius fracture immobilization using specific search terms. Identified videos were analyzed for their educational value, quality of the technical skill demonstrated, and overall metrics. Educational value was scored on a 5-point scale, with "1" indicative of low quality and "5" of high quality. Not applicable. Among the 68,366 videos identified, 16 met our inclusion criteria of being in English; performed by a health care professional or institution; and with casting being the major theme of the educational information provided. Of these 16 videos, 6 had an educational value score of 4 or 5, with the remaining 10 having a score ≤3. Although immobilization was demonstrated by cast technician specialized in orthopedics, skills were also performed by orthopedic attendants, urgent care physicians, orthopedic residents, and nurse practitioners. The credentials of the performer in 3 videos were not identified. There is a need to promote high-quality educational videos produced by established medical school faculty members on open, web-based, portals. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Nightingale, James; Wang, Qi; Grecos, Christos; Goma, Sergio
2014-02-01
High Efficiency Video Coding (HEVC), the latest video compression standard (also known as H.265), can deliver video streams of comparable quality to the current H.264 Advanced Video Coding (H.264/AVC) standard with a 50% reduction in bandwidth. Research into SHVC, the scalable extension to the HEVC standard, is still in its infancy. One important area for investigation is whether, given the greater compression ratio of HEVC (and SHVC), the loss of packets containing video content will have a greater impact on the quality of delivered video than is the case with H.264/AVC or its scalable extension H.264/SVC. In this work we empirically evaluate the layer-based, in-network adaptation of video streams encoded using SHVC in situations where dynamically changing bandwidths and datagram loss ratios require the real-time adaptation of video streams. Through the use of extensive experimentation, we establish a comprehensive set of benchmarks for SHVC-based highdefinition video streaming in loss prone network environments such as those commonly found in mobile networks. Among other results, we highlight that packet losses of only 1% can lead to a substantial reduction in PSNR of over 3dB and error propagation in over 130 pictures following the one in which the loss occurred. This work would be one of the earliest studies in this cutting-edge area that reports benchmark evaluation results for the effects of datagram loss on SHVC picture quality and offers empirical and analytical insights into SHVC adaptation to lossy, mobile networking conditions.
Veterinary students' usage and perception of video teaching resources.
Roshier, Amanda L; Foster, Neil; Jones, Michael A
2011-01-10
The purpose of our study was to use a student-centred approach to develop an online video learning resource (called 'Moo Tube') at the School of Veterinary Medicine and Science, University of Nottingham, UK and also to provide guidance for other academics in the School wishing to develop a similar resource in the future. A focus group in the format of the nominal group technique was used to garner the opinions of 12 undergraduate students (3 from year-1, 4 from year-2 and 5 from year-3). Students generated lists of items in response to key questions, these responses were thematically analysed to generate key themes which were compared between the different year groups. The number of visits to 'Moo Tube' before and after an objective structured practical examination (OSPE) was also analysed to provide data on video usage. Students highlighted a number of strengths of video resources which can be grouped into four overarching themes: (1) teaching enhancement, (2) accessibility, (3) technical quality and (4) video content. Of these themes, students rated teaching enhancement and accessibility most highly. Video usage was seen to significantly increase (P < 0.05) prior to an examination and significantly decrease (P < 0.05) following the examination. The students had a positive perception of video usage in higher education. Video usage increases prior to practical examinations. Image quality was a greater concern with year-3 students than with either year-1 or 2 students but all groups highlighted the following as important issues: i) good sound quality, ii) accessibility, including location of videos within electronic libraries, and iii) video content. Based on the findings from this study, guidelines are suggested for those developing undergraduate veterinary videos. We believe that many aspects of our list will have resonance in other areas of medicine education and higher education.
Learning to Swim Using Video Modelling and Video Feedback within a Self-Management Program
ERIC Educational Resources Information Center
Lao, So-An; Furlonger, Brett E.; Moore, Dennis W.; Busacca, Margherita
2016-01-01
Although many adults who cannot swim are primarily interested in learning by direct coaching there are options that have a focus on self-directed learning. As an alternative a self-management program combined with video modelling, video feedback and high quality and affordable video technology was used to assess its effectiveness to assisting an…
A contourlet transform based algorithm for real-time video encoding
NASA Astrophysics Data System (ADS)
Katsigiannis, Stamos; Papaioannou, Georgios; Maroulis, Dimitris
2012-06-01
In recent years, real-time video communication over the internet has been widely utilized for applications like video conferencing. Streaming live video over heterogeneous IP networks, including wireless networks, requires video coding algorithms that can support various levels of quality in order to adapt to the network end-to-end bandwidth and transmitter/receiver resources. In this work, a scalable video coding and compression algorithm based on the Contourlet Transform is proposed. The algorithm allows for multiple levels of detail, without re-encoding the video frames, by just dropping the encoded information referring to higher resolution than needed. Compression is achieved by means of lossy and lossless methods, as well as variable bit rate encoding schemes. Furthermore, due to the transformation utilized, it does not suffer from blocking artifacts that occur with many widely adopted compression algorithms. Another highly advantageous characteristic of the algorithm is the suppression of noise induced by low-quality sensors usually encountered in web-cameras, due to the manipulation of the transform coefficients at the compression stage. The proposed algorithm is designed to introduce minimal coding delay, thus achieving real-time performance. Performance is enhanced by utilizing the vast computational capabilities of modern GPUs, providing satisfactory encoding and decoding times at relatively low cost. These characteristics make this method suitable for applications like video-conferencing that demand real-time performance, along with the highest visual quality possible for each user. Through the presented performance and quality evaluation of the algorithm, experimental results show that the proposed algorithm achieves better or comparable visual quality relative to other compression and encoding methods tested, while maintaining a satisfactory compression ratio. Especially at low bitrates, it provides more human-eye friendly images compared to algorithms utilizing block-based coding, like the MPEG family, as it introduces fuzziness and blurring instead of artificial block artifacts.
Sleep quality is negatively related to video gaming volume in adults.
Exelmans, Liese; Van den Bulck, Jan
2015-04-01
Most literature on the relationship between video gaming and sleep disturbances has looked at children and adolescents. There is little research on such a relationship in adult samples. The aim of the current study was to investigate the association of video game volume with sleep quality in adults via face-to-face interviews using standardized questionnaires. Adults (n = 844, 56.2% women), aged 18-94 years old, participated in the study. Sleep quality was measured using the Pittsburgh Sleep Quality Index, and gaming volume was assessed by asking the hours of gaming on a regular weekday (Mon-Thurs), Friday and weekend day (Sat-Sun). Adjusting for gender, age, educational level, exercise and perceived stress, results of hierarchical regression analyses indicated that video gaming volume was a significant predictor of sleep quality (β = 0.145), fatigue (β = 0.109), insomnia (β = 0.120), bedtime (β = 0.100) and rise time (β = 0.168). Each additional hour of video gaming per day delayed bedtime by 6.9 min (95% confidence interval 2.0-11.9 min) and rise time by 13.8 min (95% confidence interval 7.8-19.7 min). Attributable risk for having poor sleep quality (Pittsburgh Sleep Quality Index > 5) due to gaming >1 h day was 30%. When examining the components of the Pittsburgh Sleep Quality Index using multinomial regression analysis (odds ratios with 95% confidence intervals), gaming volume significantly predicted sleep latency, sleep efficiency and use of sleep medication. In general, findings support the conclusion that gaming volume is negatively related to the overall sleep quality of adults, which might be due to underlying mechanisms of screen exposure and arousal. © 2014 European Sleep Research Society.
Low-latency situational awareness for UxV platforms
NASA Astrophysics Data System (ADS)
Berends, David C.
2012-06-01
Providing high quality, low latency video from unmanned vehicles through bandwidth-limited communications channels remains a formidable challenge for modern vision system designers. SRI has developed a number of enabling technologies to address this, including the use of SWaP-optimized Systems-on-a-Chip which provide Multispectral Fusion and Contrast Enhancement as well as H.264 video compression. Further, the use of salience-based image prefiltering prior to image compression greatly reduces output video bandwidth by selectively blurring non-important scene regions. Combined with our customization of the VLC open source video viewer for low latency video decoding, SRI developed a prototype high performance, high quality vision system for UxV application in support of very demanding system latency requirements and user CONOPS.
NASA Astrophysics Data System (ADS)
Ciaramello, Francis M.; Hemami, Sheila S.
2007-02-01
For members of the Deaf Community in the United States, current communication tools include TTY/TTD services, video relay services, and text-based communication. With the growth of cellular technology, mobile sign language conversations are becoming a possibility. Proper coding techniques must be employed to compress American Sign Language (ASL) video for low-rate transmission while maintaining the quality of the conversation. In order to evaluate these techniques, an appropriate quality metric is needed. This paper demonstrates that traditional video quality metrics, such as PSNR, fail to predict subjective intelligibility scores. By considering the unique structure of ASL video, an appropriate objective metric is developed. Face and hand segmentation is performed using skin-color detection techniques. The distortions in the face and hand regions are optimally weighted and pooled across all frames to create an objective intelligibility score for a distorted sequence. The objective intelligibility metric performs significantly better than PSNR in terms of correlation with subjective responses.
Viewer discretion advised: is YouTube a friend or foe in surgical education?
Rodriguez, H Alejandro; Young, Monica T; Jackson, Hope T; Oelschlager, Brant K; Wright, Andrew S
2018-04-01
In the current era, trainees frequently use unvetted online resources for their own education, including viewing surgical videos on YouTube. While operative videos are an important resource in surgical education, YouTube content is not selected or organized by quality but instead is ranked by popularity and other factors. This creates a potential for videos that feature poor technique or critical safety violations to become the most viewed for a given procedure. A YouTube search for "Laparoscopic cholecystectomy" was performed. Search results were screened to exclude animations and lectures; the top ten operative videos were evaluated. Three reviewers independently analyzed each of the 10 videos. Technical skill was rated using the GOALS score. Establishment of a critical view of safety (CVS) was scored according to CVS "doublet view" score, where a score of ≥5 points (out of 6) is considered satisfactory. Videos were also screened for safety concerns not listed by the previous tools. Median competence score was 8 (±1.76) and difficulty was 2 (±1.8). GOALS score median was 18 (±3.4). Only one video achieved adequate critical view of safety; median CVS score was 2 (range 0-6). Five videos were noted to have other potentially dangerous safety violations, including placing hot ultrasonic shears on the duodenum, non-clipping of the cystic artery, blind dissection in the hepatocystic triangle, and damage to the liver capsule. Top ranked laparoscopic cholecystectomy videos on YouTube show suboptimal technique with half of videos demonstrating concerning maneuvers and only one in ten having an adequate critical view of safety. While observing operative videos can be an important learning tool, surgical educators should be aware of the low quality of popular videos on YouTube. Dissemination of high-quality content on video sharing platforms should be a priority for surgical societies.
A large-scale video codec comparison of x264, x265 and libvpx for practical VOD applications
NASA Astrophysics Data System (ADS)
De Cock, Jan; Mavlankar, Aditya; Moorthy, Anush; Aaron, Anne
2016-09-01
Over the last years, we have seen exciting improvements in video compression technology, due to the introduction of HEVC and royalty-free coding specifications such as VP9. The potential compression gains of HEVC over H.264/AVC have been demonstrated in different studies, and are usually based on the HM reference software. For VP9, substantial gains over H.264/AVC have been reported in some publications, whereas others reported less optimistic results. Differences in configurations between these publications make it more difficult to assess the true potential of VP9. Practical open-source encoder implementations such as x265 and libvpx (VP9) have matured, and are now showing high compression gains over x264. In this paper, we demonstrate the potential of these encoder imple- mentations, with settings optimized for non-real-time random access, as used in a video-on-demand encoding pipeline. We report results from a large-scale video codec comparison test, which includes x264, x265 and libvpx. A test set consisting of a variety of titles with varying spatio-temporal characteristics from our catalog is used, resulting in tens of millions of encoded frames, hence larger than test sets previously used in the literature. Re- sults are reported in terms of PSNR, SSIM, MS-SSIM, VIF and the recently introduced VMAF quality metric. BD-rate calculations show that using x265 and libvpx vs. x264 can lead to significant bitrate savings for the same quality. x265 outperforms libvpx in most cases, but the performance gap narrows (or even reverses) at the higher resolutions.
Verification testing of the compression performance of the HEVC screen content coding extensions
NASA Astrophysics Data System (ADS)
Sullivan, Gary J.; Baroncini, Vittorio A.; Yu, Haoping; Joshi, Rajan L.; Liu, Shan; Xiu, Xiaoyu; Xu, Jizheng
2017-09-01
This paper reports on verification testing of the coding performance of the screen content coding (SCC) extensions of the High Efficiency Video Coding (HEVC) standard (Rec. ITU-T H.265 | ISO/IEC 23008-2 MPEG-H Part 2). The coding performance of HEVC screen content model (SCM) reference software is compared with that of the HEVC test model (HM) without the SCC extensions, as well as with the Advanced Video Coding (AVC) joint model (JM) reference software, for both lossy and mathematically lossless compression using All-Intra (AI), Random Access (RA), and Lowdelay B (LB) encoding structures and using similar encoding techniques. Video test sequences in 1920×1080 RGB 4:4:4, YCbCr 4:4:4, and YCbCr 4:2:0 colour sampling formats with 8 bits per sample are tested in two categories: "text and graphics with motion" (TGM) and "mixed" content. For lossless coding, the encodings are evaluated in terms of relative bit-rate savings. For lossy compression, subjective testing was conducted at 4 quality levels for each coding case, and the test results are presented through mean opinion score (MOS) curves. The relative coding performance is also evaluated in terms of Bjøntegaard-delta (BD) bit-rate savings for equal PSNR quality. The perceptual tests and objective metric measurements show a very substantial benefit in coding efficiency for the SCC extensions, and provided consistent results with a high degree of confidence. For TGM video, the estimated bit-rate savings ranged from 60-90% relative to the JM and 40-80% relative to the HM, depending on the AI/RA/LB configuration category and colour sampling format.
Subjective video quality evaluation of different content types under different impairments
NASA Astrophysics Data System (ADS)
Pozueco, Laura; Álvarez, Alberto; García, Xabiel; García, Roberto; Melendi, David; Díaz, Gabriel
2017-01-01
Nowadays, access to multimedia content is one of the most demanded services on the Internet. However, the transmission of audio and video over these networks is not free of problems that negatively affect user experience. Factors such as low image quality, cuts during playback or losses of audio or video, among others, can occur and there is no clear idea about the level of distortion introduced in the perceived quality. For that reason, different impairments should be evaluated based on user opinions, with the aim of analyzing the impact in the perceived quality. In this work, we carried out a subjective evaluation of different types of impairments with different types of contents, including news, cartoons, sports and action movies. A total of 100 individuals, between the ages of 20 and 68, participated in the subjective study. Results show that short-term rebuffering events negatively affect the quality of experience and that desynchronization between audio and video is the least annoying impairment. Moreover, we found that the content type determines the subjective results according to the impairment present during the playback.
MobileASL: intelligibility of sign language video over mobile phones.
Cavender, Anna; Vanam, Rahul; Barney, Dane K; Ladner, Richard E; Riskin, Eve A
2008-01-01
For Deaf people, access to the mobile telephone network in the United States is currently limited to text messaging, forcing communication in English as opposed to American Sign Language (ASL), the preferred language. Because ASL is a visual language, mobile video phones have the potential to give Deaf people access to real-time mobile communication in their preferred language. However, even today's best video compression techniques can not yield intelligible ASL at limited cell phone network bandwidths. Motivated by this constraint, we conducted one focus group and two user studies with members of the Deaf Community to determine the intelligibility effects of video compression techniques that exploit the visual nature of sign language. Inspired by eye tracking results that show high resolution foveal vision is maintained around the face, we studied region-of-interest encodings (where the face is encoded at higher quality) as well as reduced frame rates (where fewer, better quality, frames are displayed every second). At all bit rates studied here, participants preferred moderate quality increases in the face region, sacrificing quality in other regions. They also preferred slightly lower frame rates because they yield better quality frames for a fixed bit rate. The limited processing power of cell phones is a serious concern because a real-time video encoder and decoder will be needed. Choosing less complex settings for the encoder can reduce encoding time, but will affect video quality. We studied the intelligibility effects of this tradeoff and found that we can significantly speed up encoding time without severely affecting intelligibility. These results show promise for real-time access to the current low-bandwidth cell phone network through sign-language-specific encoding techniques.
NASA Astrophysics Data System (ADS)
Stewart, Brent K.; Carter, Stephen J.; Langer, Steven G.; Andrew, Rex K.
1998-06-01
Experiments using NASA's Advanced Communications Technology Satellite were conducted to provide an estimate of the compressed video quality required for preservation of clinically relevant features for the detection of trauma. Bandwidth rates of 128, 256 and 384 kbps were used. A five point Likert scale (1 equals no useful information and 5 equals good diagnostic quality) was used for a subjective preference questionnaire to evaluate the quality of the compressed ultrasound imagery at the three compression rates for several anatomical regions of interest. At 384 kbps the Likert scores (mean plus or minus SD) were abdomen (4.45 plus or minus 0.71), carotid artery (4.70 plus or minus 0.36), kidney (5.0 plus or minus 0.0), liver (4.67 plus or minus 0.58) and thyroid (4.03 plus or minus 0.74). Due to the volatile nature of the H.320 compressed digital video stream, no statistically significant results can be derived through this methodology. As the MPEG standard has at its roots many of the same intraframe and motion vector compression algorithms as the H.261 (such as that used in the previous ACTS/AMT experiments), we are using the MPEG compressed video sequences to best gauge what minimum bandwidths are necessary for preservation of clinically relevant features for the detection of trauma. We have been using an MPEG codec board to collect losslessly compressed video clips from high quality S- VHS tapes and through direct digitization of S-video. Due to the large number of videoclips and questions to be presented to the radiologists and for ease of application, we have developed a web browser interface for this video visual perception study. Due to the large numbers of observations required to reach statistical significance in most ROC studies, Kappa statistical analysis is used to analyze the degree of agreement between observers and between viewing assessment. If the degree of agreement amongst readers is high, then there is a possibility that the ratings (i.e., average Likert score at each bandwidth) do in fact reflect the dimension they are purported to reflect (video quality versus bandwidth). It is then possible to make intelligent choice of bandwidth for streaming compressed video and compressed videoclips.
Divers-Operated Underwater Photogrammetry: Applications in the Study of Antarctic Benthos
NASA Astrophysics Data System (ADS)
Piazza, P.; Cummings, V.; Lohrer, D.; Marini, S.; Marriott, P.; Menna, F.; Nocerino, E.; Peirano, A.; Schiaparelli, S.
2018-05-01
Ecological studies about marine benthic communities received a major leap from the application of a variety of non-destructive sampling and mapping techniques based on underwater image and video recording. The well-established scientific diving practice consists in the acquisition of single path or `round-trip' over elongated transects, with the imaging device oriented in a nadir looking direction. As it may be expected, the application of automatic image processing procedures to data not specifically acquired for 3D modelling can be risky, especially if proper tools for assessing the quality of the produced results are not employed. This paper, born from an international cooperation, focuses on this topic, which is of great interest for ecological and monitoring benthic studies in Antarctica. Several video footages recorded from different scientific teams in different years are processed with an automatic photogrammetric procedure and salient statistical features are reported to critically analyse the derived results. As expected, the inclusion of oblique images from additional lateral strips may improve the expected accuracy in the object space, without altering too much the current video recording practices.
Exploiting spatio-temporal characteristics of human vision for mobile video applications
NASA Astrophysics Data System (ADS)
Jillani, Rashad; Kalva, Hari
2008-08-01
Video applications on handheld devices such as smart phones pose a significant challenge to achieve high quality user experience. Recent advances in processor and wireless networking technology are producing a new class of multimedia applications (e.g. video streaming) for mobile handheld devices. These devices are light weight and have modest sizes, and therefore very limited resources - lower processing power, smaller display resolution, lesser memory, and limited battery life as compared to desktop and laptop systems. Multimedia applications on the other hand have extensive processing requirements which make the mobile devices extremely resource hungry. In addition, the device specific properties (e.g. display screen) significantly influence the human perception of multimedia quality. In this paper we propose a saliency based framework that exploits the structure in content creation as well as the human vision system to find the salient points in the incoming bitstream and adapt it according to the target device, thus improving the quality of new adapted area around salient points. Our experimental results indicate that the adaptation process that is cognizant of video content and user preferences can produce better perceptual quality video for mobile devices. Furthermore, we demonstrated how such a framework can affect user experience on a handheld device.
Automated Video Quality Assessment for Deep-Sea Video
NASA Astrophysics Data System (ADS)
Pirenne, B.; Hoeberechts, M.; Kalmbach, A.; Sadhu, T.; Branzan Albu, A.; Glotin, H.; Jeffries, M. A.; Bui, A. O. V.
2015-12-01
Video provides a rich source of data for geophysical analysis, often supplying detailed information about the environment when other instruments may not. This is especially true of deep-sea environments, where direct visual observations cannot be made. As computer vision techniques improve and volumes of video data increase, automated video analysis is emerging as a practical alternative to labor-intensive manual analysis. Automated techniques can be much more sensitive to video quality than their manual counterparts, so performing quality assessment before doing full analysis is critical to producing valid results.Ocean Networks Canada (ONC), an initiative of the University of Victoria, operates cabled ocean observatories that supply continuous power and Internet connectivity to a broad suite of subsea instruments from the coast to the deep sea, including video and still cameras. This network of ocean observatories has produced almost 20,000 hours of video (about 38 hours are recorded each day) and an additional 8,000 hours of logs from remotely operated vehicle (ROV) dives. We begin by surveying some ways in which deep-sea video poses challenges for automated analysis, including: 1. Non-uniform lighting: Single, directional, light sources produce uneven luminance distributions and shadows; remotely operated lighting equipment are also susceptible to technical failures. 2. Particulate noise: Turbidity and marine snow are often present in underwater video; particles in the water column can have sharper focus and higher contrast than the objects of interest due to their proximity to the light source and can also influence the camera's autofocus and auto white-balance routines. 3. Color distortion (low contrast): The rate of absorption of light in water varies by wavelength, and is higher overall than in air, altering apparent colors and lowering the contrast of objects at a distance.We also describe measures under development at ONC for detecting and mitigating these effects. These steps include filtering out unusable data, color and luminance balancing, and choosing the most appropriate image descriptors. We apply these techniques to generate automated quality assessment of video data and illustrate their utility with an example application where we perform vision-based substrate classification.
Side-information-dependent correlation channel estimation in hash-based distributed video coding.
Deligiannis, Nikos; Barbarien, Joeri; Jacobs, Marc; Munteanu, Adrian; Skodras, Athanassios; Schelkens, Peter
2012-04-01
In the context of low-cost video encoding, distributed video coding (DVC) has recently emerged as a potential candidate for uplink-oriented applications. This paper builds on a concept of correlation channel (CC) modeling, which expresses the correlation noise as being statistically dependent on the side information (SI). Compared with classical side-information-independent (SII) noise modeling adopted in current DVC solutions, it is theoretically proven that side-information-dependent (SID) modeling improves the Wyner-Ziv coding performance. Anchored in this finding, this paper proposes a novel algorithm for online estimation of the SID CC parameters based on already decoded information. The proposed algorithm enables bit-plane-by-bit-plane successive refinement of the channel estimation leading to progressively improved accuracy. Additionally, the proposed algorithm is included in a novel DVC architecture that employs a competitive hash-based motion estimation technique to generate high-quality SI at the decoder. Experimental results corroborate our theoretical gains and validate the accuracy of the channel estimation algorithm. The performance assessment of the proposed architecture shows remarkable and consistent coding gains over a germane group of state-of-the-art distributed and standard video codecs, even under strenuous conditions, i.e., large groups of pictures and highly irregular motion content.
An affordable wearable video system for emergency response training
NASA Astrophysics Data System (ADS)
King-Smith, Deen; Mikkilineni, Aravind; Ebert, David; Collins, Timothy; Delp, Edward J.
2009-02-01
Many emergency response units are currently faced with restrictive budgets that prohibit their use of advanced technology-based training solutions. Our work focuses on creating an affordable, mobile, state-of-the-art emergency response training solution through the integration of low-cost, commercially available products. The system we have developed consists of tracking, audio, and video capability, coupled with other sensors that can all be viewed through a unified visualization system. In this paper we focus on the video sub-system which helps provide real time tracking and video feeds from the training environment through a system of wearable and stationary cameras. These two camera systems interface with a management system that handles storage and indexing of the video during and after training exercises. The wearable systems enable the command center to have live video and tracking information for each trainee in the exercise. The stationary camera systems provide a fixed point of reference for viewing action during the exercise and consist of a small Linux based portable computer and mountable camera. The video management system consists of a server and database which work in tandem with a visualization application to provide real-time and after action review capability to the training system.
Operation quality assessment model for video conference system
NASA Astrophysics Data System (ADS)
Du, Bangshi; Qi, Feng; Shao, Sujie; Wang, Ying; Li, Weijian
2018-01-01
Video conference system has become an important support platform for smart grid operation and management, its operation quality is gradually concerning grid enterprise. First, the evaluation indicator system covering network, business and operation maintenance aspects was established on basis of video conference system's operation statistics. Then, the operation quality assessment model combining genetic algorithm with regularized BP neural network was proposed, which outputs operation quality level of the system within a time period and provides company manager with some optimization advice. The simulation results show that the proposed evaluation model offers the advantages of fast convergence and high prediction accuracy in contrast with regularized BP neural network, and its generalization ability is superior to LM-BP neural network and Bayesian BP neural network.
For Video Games, Bad News Is Good News: News Reporting of Violent Video Game Studies.
Copenhaver, Allen; Mitrofan, Oana; Ferguson, Christopher J
2017-12-01
News coverage of video game violence studies has been critiqued for focusing mainly on studies supporting negative effects and failing to report studies that did not find evidence for such effects. These concerns were tested in a sample of 68 published studies using child and adolescent samples. Contrary to our hypotheses, study effect size was not a predictor of either newspaper coverage or publication in journals with a high-impact factor. However, a relationship between poorer study quality and newspaper coverage approached significance. High-impact journals were not found to publish studies with higher quality. Poorer quality studies, which tended to highlight negative findings, also received more citations in scholarly sources. Our findings suggest that negative effects of violent video games exposure in children and adolescents, rather than large effect size or high methodological quality, increase the likelihood of a study being cited in other academic publications and subsequently receiving news media coverage.
Content-Aware Video Adaptation under Low-Bitrate Constraint
NASA Astrophysics Data System (ADS)
Hsiao, Ming-Ho; Chen, Yi-Wen; Chen, Hua-Tsung; Chou, Kuan-Hung; Lee, Suh-Yin
2007-12-01
With the development of wireless network and the improvement of mobile device capability, video streaming is more and more widespread in such an environment. Under the condition of limited resource and inherent constraints, appropriate video adaptations have become one of the most important and challenging issues in wireless multimedia applications. In this paper, we propose a novel content-aware video adaptation in order to effectively utilize resource and improve visual perceptual quality. First, the attention model is derived from analyzing the characteristics of brightness, location, motion vector, and energy features in compressed domain to reduce computation complexity. Then, through the integration of attention model, capability of client device and correlational statistic model, attractive regions of video scenes are derived. The information object- (IOB-) weighted rate distortion model is used for adjusting the bit allocation. Finally, the video adaptation scheme dynamically adjusts video bitstream in frame level and object level. Experimental results validate that the proposed scheme achieves better visual quality effectively and efficiently.
Adaptive compressed sensing of multi-view videos based on the sparsity estimation
NASA Astrophysics Data System (ADS)
Yang, Senlin; Li, Xilong; Chong, Xin
2017-11-01
The conventional compressive sensing for videos based on the non-adaptive linear projections, and the measurement times is usually set empirically. As a result, the quality of videos reconstruction is always affected. Firstly, the block-based compressed sensing (BCS) with conventional selection for compressive measurements was described. Then an estimation method for the sparsity of multi-view videos was proposed based on the two dimensional discrete wavelet transform (2D DWT). With an energy threshold given beforehand, the DWT coefficients were processed with both energy normalization and sorting by descending order, and the sparsity of the multi-view video can be achieved by the proportion of dominant coefficients. And finally, the simulation result shows that, the method can estimate the sparsity of video frame effectively, and provides an active basis for the selection of compressive observation times. The result also shows that, since the selection of observation times is based on the sparsity estimated with the energy threshold provided, the proposed method can ensure the reconstruction quality of multi-view videos.
Ipsiroglu, Osman S; Hung, Yi-Hsuan Amy; Chan, Forson; Ross, Michelle L; Veer, Dorothee; Soo, Sonja; Ho, Gloria; Berger, Mai; McAllister, Graham; Garn, Heinrich; Kloesch, Gerhard; Barbosa, Adriano Vilela; Stockler, Sylvia; McKellin, William; Vatikiotis-Bateson, Eric
2015-01-01
Advanced video technology is available for sleep-laboratories. However, low-cost equipment for screening in the home setting has not been identified and tested, nor has a methodology for analysis of video recordings been suggested. We investigated different combinations of hardware/software for home-videosomnography (HVS) and established a process for qualitative and quantitative analysis of HVS-recordings. A case vignette (HVS analysis for a 5.5-year-old girl with major insomnia and several co-morbidities) demonstrates how methodological considerations were addressed and how HVS added value to clinical assessment. We suggest an "ideal set of hardware/software" that is reliable, affordable (∼$500) and portable (=2.8 kg) to conduct non-invasive HVS, which allows time-lapse analyses. The equipment consists of a net-book, a camera with infrared optics, and a video capture device. (1) We present an HVS-analysis protocol consisting of three steps of analysis at varying replay speeds: (a) basic overview and classification at 16× normal speed; (b) second viewing and detailed descriptions at 4-8× normal speed, and (c) viewing, listening, and in-depth descriptions at real-time speed. (2) We also present a custom software program that facilitates video analysis and note-taking (Annotator(©)), and Optical Flow software that automatically quantifies movement for internal quality control of the HVS-recording. The case vignette demonstrates how the HVS-recordings revealed the dimension of insomnia caused by restless legs syndrome, and illustrated the cascade of symptoms, challenging behaviors, and resulting medications. The strategy of using HVS, although requiring validation and reliability testing, opens the floor for a new "observational sleep medicine," which has been useful in describing discomfort-related behavioral movement patterns in patients with communication difficulties presenting with challenging/disruptive sleep/wake behaviors.
Secure and Efficient Reactive Video Surveillance for Patient Monitoring.
Braeken, An; Porambage, Pawani; Gurtov, Andrei; Ylianttila, Mika
2016-01-02
Video surveillance is widely deployed for many kinds of monitoring applications in healthcare and assisted living systems. Security and privacy are two promising factors that align the quality and validity of video surveillance systems with the caliber of patient monitoring applications. In this paper, we propose a symmetric key-based security framework for the reactive video surveillance of patients based on the inputs coming from data measured by a wireless body area network attached to the human body. Only authenticated patients are able to activate the video cameras, whereas the patient and authorized people can consult the video data. User and location privacy are at each moment guaranteed for the patient. A tradeoff between security and quality of service is defined in order to ensure that the surveillance system gets activated even in emergency situations. In addition, the solution includes resistance against tampering with the device on the patient's side.
Secure and Efficient Reactive Video Surveillance for Patient Monitoring
Braeken, An; Porambage, Pawani; Gurtov, Andrei; Ylianttila, Mika
2016-01-01
Video surveillance is widely deployed for many kinds of monitoring applications in healthcare and assisted living systems. Security and privacy are two promising factors that align the quality and validity of video surveillance systems with the caliber of patient monitoring applications. In this paper, we propose a symmetric key-based security framework for the reactive video surveillance of patients based on the inputs coming from data measured by a wireless body area network attached to the human body. Only authenticated patients are able to activate the video cameras, whereas the patient and authorized people can consult the video data. User and location privacy are at each moment guaranteed for the patient. A tradeoff between security and quality of service is defined in order to ensure that the surveillance system gets activated even in emergency situations. In addition, the solution includes resistance against tampering with the device on the patient’s side. PMID:26729130
Tuong, William; Armstrong, April W
2015-02-16
Increasing participant satisfaction with health interventions can improve compliance with recommended health behaviors and lead to better health outcomes. However, factors that influence participant satisfaction have not been well studied in dermatology-specific behavioral health interventions. We sought to assess participant satisfaction of either an appearance-based educational video or a health-based educational video promoting sunscreen use along dimensions of usefulness of educational content, message appeal, and presentation quality. In a randomized controlled trial, participants were randomized 1:1 to view an appearance-based video or a health-based video. After six weeks, participant satisfaction with the educational videos was assessed. Fifty high school students were enrolled and completed the study. Participant satisfaction ratings were assessed using a pre-tested 10-point assessment scale. The participants rated the usefulness of the appearance-based video (8.1 ± 1.2) significantly higher than the health-based video (6.4 ± 1.4, p<0.001). The message appeal of the appearance-based video (8.3 ± 1.0) was also significantly higher than the health-based video (6.6 ± 1.6, p<0.001). The presentation quality rating was similar between the appearance-based video (7.8 ± 1.3) and the health-based video (8.1 ± 1.3), p=0.676. Adolescents rated the appearance-based video higher than the health-based video in terms of usefulness of educational content and message appeal.
Descriptive analysis of YouTube music therapy videos.
Gooding, Lori F; Gregory, Dianne
2011-01-01
The purpose of this study was to conduct a descriptive analysis of music therapy-related videos on YouTube. Preliminary searches using the keywords music therapy, music therapy session, and "music therapy session" resulted in listings of 5000, 767, and 59 videos respectively. The narrowed down listing of 59 videos was divided between two investigators and reviewed in order to determine their relationship to actual music therapy practice. A total of 32 videos were determined to be depictions of music therapy sessions. These videos were analyzed using a 16-item investigator-created rubric that examined both video specific information and therapy specific information. Results of the analysis indicated that audio and visual quality was adequate, while narrative descriptions and identification information were ineffective in the majority of the videos. The top 5 videos (based on the highest number of viewings in the sample) were selected for further analysis in order to investigate demonstration of the Professional Level of Practice Competencies set forth in the American Music Therapy Association (AMTA) Professional Competencies (AMTA, 2008). Four of the five videos met basic competency criteria, with the quality of the fifth video precluding evaluation of content. Of particular interest is the fact that none of the videos included credentialing information. Results of this study suggest the need to consider ways to ensure accurate dissemination of music therapy-related information in the YouTube environment, ethical standards when posting music therapy session videos, and the possibility of creating AMTA standards for posting music therapy related video.
47 CFR Appendix - Technical Appendix 1
Code of Federal Regulations, 2010 CFR
2010-10-01
... display program material that has been encoded in any and all of the video formats contained in Table A3... frame rate of the transmitted video format. 2. Output Formats Equipment shall support 4:3 center cut-out... for composite video (yellow). Output shall produce video with ITU-R BT.500-11 quality scale of Grade 4...
NASA Astrophysics Data System (ADS)
Pei, Yong; Modestino, James W.
2004-12-01
Digital video delivered over wired-to-wireless networks is expected to suffer quality degradation from both packet loss and bit errors in the payload. In this paper, the quality degradation due to packet loss and bit errors in the payload are quantitatively evaluated and their effects are assessed. We propose the use of a concatenated forward error correction (FEC) coding scheme employing Reed-Solomon (RS) codes and rate-compatible punctured convolutional (RCPC) codes to protect the video data from packet loss and bit errors, respectively. Furthermore, the performance of a joint source-channel coding (JSCC) approach employing this concatenated FEC coding scheme for video transmission is studied. Finally, we describe an improved end-to-end architecture using an edge proxy in a mobile support station to implement differential error protection for the corresponding channel impairments expected on the two networks. Results indicate that with an appropriate JSCC approach and the use of an edge proxy, FEC-based error-control techniques together with passive error-recovery techniques can significantly improve the effective video throughput and lead to acceptable video delivery quality over time-varying heterogeneous wired-to-wireless IP networks.
Experimental design and analysis of JND test on coded image/video
NASA Astrophysics Data System (ADS)
Lin, Joe Yuchieh; Jin, Lina; Hu, Sudeng; Katsavounidis, Ioannis; Li, Zhi; Aaron, Anne; Kuo, C.-C. Jay
2015-09-01
The visual Just-Noticeable-Difference (JND) metric is characterized by the detectable minimum amount of two visual stimuli. Conducting the subjective JND test is a labor-intensive task. In this work, we present a novel interactive method in performing the visual JND test on compressed image/video. JND has been used to enhance perceptual visual quality in the context of image/video compression. Given a set of coding parameters, a JND test is designed to determine the distinguishable quality level against a reference image/video, which is called the anchor. The JND metric can be used to save coding bitrates by exploiting the special characteristics of the human visual system. The proposed JND test is conducted using a binary-forced choice, which is often adopted to discriminate the difference in perception in a psychophysical experiment. The assessors are asked to compare coded image/video pairs and determine whether they are of the same quality or not. A bisection procedure is designed to find the JND locations so as to reduce the required number of comparisons over a wide range of bitrates. We will demonstrate the efficiency of the proposed JND test, report experimental results on the image and video JND tests.
Qualitative analysis of Parkinson's disease information on social media: the case of YouTube™.
Al-Busaidi, Ibrahim Saleh; Anderson, Tim J; Alamri, Yassar
2017-09-01
There is a paucity of data pertaining to the usefulness of information presented on social media platforms on chronic neuropsychiatric conditions such as Parkinson's disease (PD). The aim of this study was to examine the quality of YouTube™ videos that deliver general information on PD and the availability and design of instructional videos addressing the caregiving role in PD. YouTube™ was searched using the keyword "Parkinson's disease" for relevant videos. Videos were assessed for usefulness and accuracy based on pre-defined criteria. Data on video characteristics including total viewership, duration, ratings, and source of videos were collated. Instructional PD videos that addressed the role of caregivers were examined closely for the design and scope of instructional content. A total of 100 videos met the inclusion criteria. Just under a third of videos (28%) was uploaded by trusted academic organisations. Overall, 15% of PD videos were found to be somewhat useful and only 4% were assessed as providing very useful PD information; 3% of surveyed videos were misleading. The mean number of video views (regardless of video source) was not significantly different between the different video ratings ( p = 0.86). Although personal videos trended towards being less useful than videos from academic organisations, this association was not statistically significant ( p = 0.13). To our knowledge, this is the first study to assess the usefulness of PD information on the largest video-sharing website, YouTube™. In general, the overall quality of information presented in the videos screened was mediocre. Viewership of accurate vs. misleading information was, however, very similar. Therefore, healthcare providers should direct PD patients and their families to the resources that provide reliable and accurate information.
Experiences of citizen-based reporting of rainfall events using lab-generated videos
NASA Astrophysics Data System (ADS)
Alfonso, Leonardo; Chacon, Juan
2016-04-01
Hydrologic studies rely on the availability of good-quality precipitation estimates. However, in remote areas of the world and particularly in developing countries, ground-based measurement networks are either sparse or nonexistent. This creates difficulties in the estimation of precipitation, which limits the development of hydrologic forecasting and early warning systems for these regions. The EC-FP7 WeSenseIt project aims at exploring the involvement of citizens in the observation of the water cycle with innovative sensor technologies, including mobile telephony. In particular, the project explores the use of a smartphone applications to facilitate the reporting water-related situations. Apart from the challenge of using such information for scientific purposes, the citizen engagement is one of the most important issues to address. To this end effortless methods for reporting need to be developed in order to involve as many people as possible in these experiments. A potential solution to overcome these drawbacks, consisting on lab-controlled rainfall videos have been produced to help mapping the extent and distribution of rainfall fields with minimum effort [1]. In addition, the quality of the collected rainfall information has also been studied [2] by means of different experiments with students. The present research shows the latest results of the application of this method and evaluates the experiences in some cases. [1] Alfonso, L., J. Chacón, and G. Peña-Castellanos (2015), Allowing Citizens to Effortlessly Become Rainfall Sensors, in 36th IAHR World Congress edited, The Hague, the Netherlands [2] Cortes-Arevalo, J., J. Chacón, L. Alfonso, and T. Bogaard (2015), Evaluating data quality collected by using a video rating scale to estimate and report rainfall intensity, in 36th IAHR World Congress edited, The Hague, the Netherlands
YouTube as a source of clinical skills education.
Duncan, Ian; Yarwood-Ross, Lee; Haigh, Carol
2013-12-01
YouTube may be viewed as a great 'time waster' but a significant amount of educative material can be found if the user is carefully selective. Interestingly, the growth of educational video on YouTube is closely associated to video viewership which increased from 22% to 38% between 2007 and 2009. This paper describes the findings of a study undertaken to assess the quality of clinical skills videos available on the video sharing site YouTube. This study evaluated 100 YouTube sites, approximately 1500 min or 25 h worth of content across 10 common clinical skill related topics. In consultation with novice practitioners, nurses in the first year of their university diploma programme, we identified ten common clinical skills that typically students would explore in more detail or would wish to revisit outside of the formal teaching environment. For each of these topics, we viewed each of the first 10 videos on the YouTube website. The videos were evaluated using a modification of the criteria outlined in Evaluation of Video Media Guideline. The topic with the biggest number of both postings and views was cardiopulmonary resuscitation and more specialist, nursing or health related topics such as managing a syringe driver or undertaking a pain assessment had less video content and lower numbers of viewers. Only one video out of the 100 analysed could be categorised as 'good' and that was the one in the Cannulation section. 60% of the CPR and venepuncture content was categorised as 'satisfactory'. There is a clear need for the quality of YouTube videos to be subjected to a rigorous evaluation. Lecturers should be more proactive in recommending suitable YouTube material as supplementary learning materials after appropriately checking for quality. Copyright © 2013 Elsevier Ltd. All rights reserved.
The influence of motion quality on responses towards video playback stimuli.
Ware, Emma; Saunders, Daniel R; Troje, Nikolaus F
2015-05-11
Visual motion, a critical cue in communication, can be manipulated and studied using video playback methods. A primary concern for the video playback researcher is the degree to which objects presented on video appear natural to the non-human subject. Here we argue that the quality of motion cues on video, as determined by the video's image presentation rate (IPR), are of particular importance in determining a subject's social response behaviour. We present an experiment testing the effect of variations in IPR on pigeon (Columbia livia) response behaviour towards video images of courting opposite sex partners. Male and female pigeons were presented with three video playback stimuli, each containing a different social partner. Each stimulus was then modified to appear at one of three IPRs: 15, 30 or 60 progressive (p) frames per second. The results showed that courtship behaviour became significantly longer in duration as IPR increased. This finding implies that the IPR significantly affects the perceived quality of motion cues impacting social behaviour. In males we found that the duration of courtship also depended on the social partner viewed and that this effect interacted with the effects of IPR on behaviour. Specifically, the effect of social partner reached statistical significance only when the stimuli were displayed at 60 p, demonstrating the potential for erroneous results when insufficient IPRs are used. In addition to demonstrating the importance of IPR in video playback experiments, these findings help to highlight and describe the role of visual motion processing in communication behaviour. © 2015. Published by The Company of Biologists Ltd.
Open-source telemedicine platform for wireless medical video communication.
Panayides, A; Eleftheriou, I; Pantziaris, M
2013-01-01
An m-health system for real-time wireless communication of medical video based on open-source software is presented. The objective is to deliver a low-cost telemedicine platform which will allow for reliable remote diagnosis m-health applications such as emergency incidents, mass population screening, and medical education purposes. The performance of the proposed system is demonstrated using five atherosclerotic plaque ultrasound videos. The videos are encoded at the clinically acquired resolution, in addition to lower, QCIF, and CIF resolutions, at different bitrates, and four different encoding structures. Commercially available wireless local area network (WLAN) and 3.5G high-speed packet access (HSPA) wireless channels are used to validate the developed platform. Objective video quality assessment is based on PSNR ratings, following calibration using the variable frame delay (VFD) algorithm that removes temporal mismatch between original and received videos. Clinical evaluation is based on atherosclerotic plaque ultrasound video assessment protocol. Experimental results show that adequate diagnostic quality wireless medical video communications are realized using the designed telemedicine platform. HSPA cellular networks provide for ultrasound video transmission at the acquired resolution, while VFD algorithm utilization bridges objective and subjective ratings.
Open-Source Telemedicine Platform for Wireless Medical Video Communication
Panayides, A.; Eleftheriou, I.; Pantziaris, M.
2013-01-01
An m-health system for real-time wireless communication of medical video based on open-source software is presented. The objective is to deliver a low-cost telemedicine platform which will allow for reliable remote diagnosis m-health applications such as emergency incidents, mass population screening, and medical education purposes. The performance of the proposed system is demonstrated using five atherosclerotic plaque ultrasound videos. The videos are encoded at the clinically acquired resolution, in addition to lower, QCIF, and CIF resolutions, at different bitrates, and four different encoding structures. Commercially available wireless local area network (WLAN) and 3.5G high-speed packet access (HSPA) wireless channels are used to validate the developed platform. Objective video quality assessment is based on PSNR ratings, following calibration using the variable frame delay (VFD) algorithm that removes temporal mismatch between original and received videos. Clinical evaluation is based on atherosclerotic plaque ultrasound video assessment protocol. Experimental results show that adequate diagnostic quality wireless medical video communications are realized using the designed telemedicine platform. HSPA cellular networks provide for ultrasound video transmission at the acquired resolution, while VFD algorithm utilization bridges objective and subjective ratings. PMID:23573082
HealthTrust: A Social Network Approach for Retrieving Online Health Videos
Karlsen, Randi; Melton, Genevieve B
2012-01-01
Background Social media are becoming mainstream in the health domain. Despite the large volume of accurate and trustworthy health information available on social media platforms, finding good-quality health information can be difficult. Misleading health information can often be popular (eg, antivaccination videos) and therefore highly rated by general search engines. We believe that community wisdom about the quality of health information can be harnessed to help create tools for retrieving good-quality social media content. Objectives To explore approaches for extracting metrics about authoritativeness in online health communities and how these metrics positively correlate with the quality of the content. Methods We designed a metric, called HealthTrust, that estimates the trustworthiness of social media content (eg, blog posts or videos) in a health community. The HealthTrust metric calculates reputation in an online health community based on link analysis. We used the metric to retrieve YouTube videos and channels about diabetes. In two different experiments, health consumers provided 427 ratings of 17 videos and professionals gave 162 ratings of 23 videos. In addition, two professionals reviewed 30 diabetes channels. Results HealthTrust may be used for retrieving online videos on diabetes, since it performed better than YouTube Search in most cases. Overall, of 20 potential channels, HealthTrust’s filtering allowed only 3 bad channels (15%) versus 8 (40%) on the YouTube list. Misleading and graphic videos (eg, featuring amputations) were more commonly found by YouTube Search than by searches based on HealthTrust. However, some videos from trusted sources had low HealthTrust scores, mostly from general health content providers, and therefore not highly connected in the diabetes community. When comparing video ratings from our reviewers, we found that HealthTrust achieved a positive and statistically significant correlation with professionals (Pearson r 10 = .65, P = .02) and a trend toward significance with health consumers (r 7 = .65, P = .06) with videos on hemoglobinA1 c, but it did not perform as well with diabetic foot videos. Conclusions The trust-based metric HealthTrust showed promising results when used to retrieve diabetes content from YouTube. Our research indicates that social network analysis may be used to identify trustworthy social media in health communities. PMID:22356723
Secured web-based video repository for multicenter studies
Yan, Ling; Hicks, Matt; Winslow, Korey; Comella, Cynthia; Ludlow, Christy; Jinnah, H. A; Rosen, Ami R; Wright, Laura; Galpern, Wendy R; Perlmutter, Joel S
2015-01-01
Background We developed a novel secured web-based dystonia video repository for the Dystonia Coalition, part of the Rare Disease Clinical Research network funded by the Office of Rare Diseases Research and the National Institute of Neurological Disorders and Stroke. A critical component of phenotypic data collection for all projects of the Dystonia Coalition includes a standardized video of each participant. We now describe our method for collecting, serving and securing these videos that is widely applicable to other studies. Methods Each recruiting site uploads standardized videos to a centralized secured server for processing to permit website posting. The streaming technology used to view the videos from the website does not allow downloading of video files. With appropriate institutional review board approval and agreement with the hosting institution, users can search and view selected videos on the website using customizable, permissions-based access that maintains security yet facilitates research and quality control. Results This approach provides a convenient platform for researchers across institutions to evaluate and analyze shared video data. We have applied this methodology for quality control, confirmation of diagnoses, validation of rating scales, and implementation of new research projects. Conclusions We believe our system can be a model for similar projects that require access to common video resources. PMID:25630890
The Use of Smart Glasses for Surgical Video Streaming.
Hiranaka, Takafumi; Nakanishi, Yuta; Fujishiro, Takaaki; Hida, Yuichi; Tsubosaka, Masanori; Shibata, Yosaku; Okimura, Kenjiro; Uemoto, Harunobu
2017-04-01
Observation of surgical procedures performed by experts is extremely important for acquisition and improvement of surgical skills. Smart glasses are small computers, which comprise a head-mounted monitor and video camera, and can be connected to the internet. They can be used for remote observation of surgeries by video streaming. Although Google Glass is the most commonly used smart glasses for medical purposes, it is still unavailable commercially and has some limitations. This article reports the use of a different type of smart glasses, InfoLinker, for surgical video streaming. InfoLinker has been commercially available in Japan for industrial purposes for more than 2 years. It is connected to a video server via wireless internet directly, and streaming video can be seen anywhere an internet connection is available. We have attempted live video streaming of knee arthroplasty operations that were viewed at several different locations, including foreign countries, on a common web browser. Although the quality of video images depended on the resolution and dynamic range of the video camera, speed of internet connection, and the wearer's attention to minimize image shaking, video streaming could be easily performed throughout the procedure. The wearer could confirm the quality of the video as the video was being shot by the head-mounted display. The time and cost for observation of surgical procedures can be reduced by InfoLinker, and further improvement of hardware as well as the wearer's video shooting technique is expected. We believe that this can be used in other medical settings.
VASIR: An Open-Source Research Platform for Advanced Iris Recognition Technologies.
Lee, Yooyoung; Micheals, Ross J; Filliben, James J; Phillips, P Jonathon
2013-01-01
The performance of iris recognition systems is frequently affected by input image quality, which in turn is vulnerable to less-than-optimal conditions due to illuminations, environments, and subject characteristics (e.g., distance, movement, face/body visibility, blinking, etc.). VASIR (Video-based Automatic System for Iris Recognition) is a state-of-the-art NIST-developed iris recognition software platform designed to systematically address these vulnerabilities. We developed VASIR as a research tool that will not only provide a reference (to assess the relative performance of alternative algorithms) for the biometrics community, but will also advance (via this new emerging iris recognition paradigm) NIST's measurement mission. VASIR is designed to accommodate both ideal (e.g., classical still images) and less-than-ideal images (e.g., face-visible videos). VASIR has three primary modules: 1) Image Acquisition 2) Video Processing, and 3) Iris Recognition. Each module consists of several sub-components that have been optimized by use of rigorous orthogonal experiment design and analysis techniques. We evaluated VASIR performance using the MBGC (Multiple Biometric Grand Challenge) NIR (Near-Infrared) face-visible video dataset and the ICE (Iris Challenge Evaluation) 2005 still-based dataset. The results showed that even though VASIR was primarily developed and optimized for the less-constrained video case, it still achieved high verification rates for the traditional still-image case. For this reason, VASIR may be used as an effective baseline for the biometrics community to evaluate their algorithm performance, and thus serves as a valuable research platform.
VASIR: An Open-Source Research Platform for Advanced Iris Recognition Technologies
Lee, Yooyoung; Micheals, Ross J; Filliben, James J; Phillips, P Jonathon
2013-01-01
The performance of iris recognition systems is frequently affected by input image quality, which in turn is vulnerable to less-than-optimal conditions due to illuminations, environments, and subject characteristics (e.g., distance, movement, face/body visibility, blinking, etc.). VASIR (Video-based Automatic System for Iris Recognition) is a state-of-the-art NIST-developed iris recognition software platform designed to systematically address these vulnerabilities. We developed VASIR as a research tool that will not only provide a reference (to assess the relative performance of alternative algorithms) for the biometrics community, but will also advance (via this new emerging iris recognition paradigm) NIST’s measurement mission. VASIR is designed to accommodate both ideal (e.g., classical still images) and less-than-ideal images (e.g., face-visible videos). VASIR has three primary modules: 1) Image Acquisition 2) Video Processing, and 3) Iris Recognition. Each module consists of several sub-components that have been optimized by use of rigorous orthogonal experiment design and analysis techniques. We evaluated VASIR performance using the MBGC (Multiple Biometric Grand Challenge) NIR (Near-Infrared) face-visible video dataset and the ICE (Iris Challenge Evaluation) 2005 still-based dataset. The results showed that even though VASIR was primarily developed and optimized for the less-constrained video case, it still achieved high verification rates for the traditional still-image case. For this reason, VASIR may be used as an effective baseline for the biometrics community to evaluate their algorithm performance, and thus serves as a valuable research platform. PMID:26401431
Teaching Corporate Culture Using Interactive Video Training.
ERIC Educational Resources Information Center
Gardner, P. R.
The Westinghouse Hanford Company Total Quality Program includes the development of Hanford General Employee Training (HGET), an interactive video course. The commitment to total quality is developed in both new and requalifying employees by requiring them to make positive choices when confronted with real life scenarios showing violations of…
The emerging High Efficiency Video Coding standard (HEVC)
NASA Astrophysics Data System (ADS)
Raja, Gulistan; Khan, Awais
2013-12-01
High definition video (HDV) is becoming popular day by day. This paper describes the performance analysis of latest upcoming video standard known as High Efficiency Video Coding (HEVC). HEVC is designed to fulfil all the requirements for future high definition videos. In this paper, three configurations (intra only, low delay and random access) of HEVC are analyzed using various 480p, 720p and 1080p high definition test video sequences. Simulation results show the superior objective and subjective quality of HEVC.
Chamarro, Andres; Carbonell, Xavier; Manresa, Josep Maria; Munoz-Miralles, Raquel; Ortega-Gonzalez, Raquel; Lopez-Morron, M Rosa; Batalla-Martinez, Carme; Toran-Monserrat, Pere
2014-01-01
The aim of this study is to validate the Video Game-Related Experiences Questionnaire (CERV in Spanish). The questionnaire consists of 17 items, developed from the CERI (Internet-Related Experiences Questionnaire - Beranuy and cols.), and assesses the problematic use of non-massive video games. It was validated for adolescents in Compulsory Secondary Education. To validate the questionnaire, a confirmatory factor analysis (CFA) and an internal consistency analysis were carried out. The factor structure shows two factors: (a) Psychological dependence and use for evasion; and (b) Negative consequences of using video games. Two cut-off points were established for people with no problems in their use of video games (NP), with potential problems in their use of video games (PP), and with serious problems in their use of video games (SP). Results show that there is higher prevalence among males and that problematic use decreases with age. The CERV seems to be a good instrument for the screening of adolescents with difficulties deriving from video game use. Further research should relate problematic video game use with difficulties in other life domains, such as the academic field.
Video Use in Teacher Education: A Survey of Teacher-Educators' Practices across Disciplines
ERIC Educational Resources Information Center
Arya, Poonam; Christ, Tanya; Chiu, Ming Ming
2016-01-01
Video methods utilize tenets of high quality teacher education and support education students' learning and application of learning to teaching practices. However, how frequently video is used in teacher education, and in what ways is unknown. Therefore, this study used survey data to identify the extent to which 94 teacher-educators used video in…
Video-Based Modeling: Differential Effects due to Treatment Protocol
ERIC Educational Resources Information Center
Mason, Rose A.; Ganz, Jennifer B.; Parker, Richard I.; Boles, Margot B.; Davis, Heather S.; Rispoli, Mandy J.
2013-01-01
Identifying evidence-based practices for individuals with disabilities requires specification of procedural implementation. Video-based modeling (VBM), consisting of both video self-modeling and video modeling with others as model (VMO), is one class of interventions that has frequently been explored in the literature. However, current information…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-08
... Commercial Access; Development of Competition and Diversity in Video Programming Distribution and Carriage... contained in the Second Report and Order, FCC 11-119, pertaining to carriage of video programming vendors by multichannel video programming distributors (program carriage rules). This notice is consistent with the Secord...
NASA Astrophysics Data System (ADS)
Palma, V.; Carli, M.; Neri, A.
2011-02-01
In this paper a Multi-view Distributed Video Coding scheme for mobile applications is presented. Specifically a new fusion technique between temporal and spatial side information in Zernike Moments domain is proposed. Distributed video coding introduces a flexible architecture that enables the design of very low complex video encoders compared to its traditional counterparts. The main goal of our work is to generate at the decoder the side information that optimally blends temporal and interview data. Multi-view distributed coding performance strongly depends on the side information quality built at the decoder. At this aim for improving its quality a spatial view compensation/prediction in Zernike moments domain is applied. Spatial and temporal motion activity have been fused together to obtain the overall side-information. The proposed method has been evaluated by rate-distortion performances for different inter-view and temporal estimation quality conditions.
NASA Astrophysics Data System (ADS)
Nishikawa, Robert M.; MacMahon, Heber; Doi, Kunio; Bosworth, Eric
1991-05-01
Communication between radiologists and clinicians could be improved if a secondary image (copy of the original image) accompanied the radiologic report. In addition, the number of lost original radiographs could be decreased, since clinicians would have less need to borrow films. The secondary image should be simple and inexpensive to produce, while providing sufficient image quality for verification of the diagnosis. We are investigating the potential usefulness of a video printer for producing copies of radiographs, i.e. images printed on thermal paper. The video printer we examined (Seikosha model VP-3500) can provide 64 shades of gray. It is capable of recording images up to 1,280 pixels by 1,240 lines and can accept any raster-type video signal. The video printer was characterized in terms of its linearity, contrast, latitude, resolution, and noise properties. The quality of video-printer images was also evaluated in an observer study using portable chest radiographs. We found that observers could confirm up to 90 of the reported findings in the thorax using video- printer images, when the original radiographs were of high quality. The number of verified findings was diminished when high spatial resolution was required (e.g. detection of a subtle pneumothorax) or when a low-contrast finding was located in the mediastinal area or below the diaphragm (e.g. nasogastric tubes).
Evaluation of Hands-On Clinical Exam Performance Using Marker-less Video Tracking.
Azari, David; Pugh, Carla; Laufer, Shlomi; Cohen, Elaine; Kwan, Calvin; Chen, Chia-Hsiung Eric; Yen, Thomas Y; Hu, Yu Hen; Radwin, Robert
2014-09-01
This study investigates the potential of using marker-less video tracking of the hands for evaluating hands-on clinical skills. Experienced family practitioners attending a national conference were recruited and asked to conduct a breast examination on a simulator that simulates different clinical presentations. Videos were made of the clinician's hands during the exam and video processing software for tracking hand motion to quantify hand motion kinematics was used. Practitioner motion patterns indicated consistent behavior of participants across multiple pathologies. Different pathologies exhibited characteristic motion patterns in the aggregate at specific parts of an exam, indicating consistent inter-participant behavior. Marker-less video kinematic tracking therefore shows promise in discriminating between different examination procedures, clinicians, and pathologies.
NASA Astrophysics Data System (ADS)
Rhzanov, Y.; Beaulieu, S.; Soule, S. A.; Shank, T.; Fornari, D.; Mayer, L. A.
2005-12-01
Many advances in understanding geologic, tectonic, biologic, and sedimentologic processes in the deep ocean are facilitated by direct observation of the seafloor. However, making such observations is both difficult and expensive. Optical systems (e.g., video, still camera, or direct observation) will always be constrained by the severe attenuation of light in the deep ocean, limiting the field of view to distances that are typically less than 10 meters. Acoustic systems can 'see' much larger areas, but at the cost of spatial resolution. Ultimately, scientists want to study and observe deep-sea processes in the same way we do land-based phenomena so that the spatial distribution and juxtaposition of processes and features can be resolved. We have begun development of algorithms that will, in near real-time, generate mosaics from video collected by deep-submergence vehicles. Mosaics consist of >>10 video frames and can cover 100's of square-meters. This work builds on a publicly available still and video mosaicking software package developed by Rzhanov and Mayer. Here we present the results of initial tests of data collection methodologies (e.g., transects across the seafloor and panoramas across features of interest), algorithm application, and GIS integration conducted during a recent cruise to the Eastern Galapagos Spreading Center (0 deg N, 86 deg W). We have developed a GIS database for the region that will act as a means to access and display mosaics within a geospatially-referenced framework. We have constructed numerous mosaics using both video and still imagery and assessed the quality of the mosaics (including registration errors) under different lighting conditions and with different navigation procedures. We have begun to develop algorithms for efficient and timely mosaicking of collected video as well as integration with navigation data for georeferencing the mosaics. Initial results indicate that operators must be properly versed in the control of the video systems as well as maintaining vehicle attitude and altitude in order to achieve the best results possible.
Video quality of 3G videophones for telephone cardiopulmonary resuscitation.
Tränkler, Uwe; Hagen, Oddvar; Horsch, Alexander
2008-01-01
We simulated a cardiopulmonary resuscitation (CPR) scene with a manikin and used two 3G videophones on the caller's side to transmit video to a laptop PC. Five observers (two doctors with experience in emergency medicine and three paramedics) evaluated the video. They judged whether the manikin was breathing and whether they would give advice for CPR; they also graded the confidence of their decision-making. Breathing was only visible from certain orientations of the videophones, at distances below 150 cm with good illumination and a still background. Since the phones produced a degradation in colours and shadows, detection of breathing mainly depended on moving contours. Low camera positioning produced better results than having the camera high up. Darkness, shaking of the camera and a moving background made detection of breathing almost impossible. The video from the two 3G videophones that were tested was of sufficient quality for telephone CPR provided that camera orientation, distance, illumination and background were carefully chosen. Thus it seems possible to use 3G videophones for emergency calls involving CPR. However, further studies on the required video quality in different scenarios are necessary.
Wang, Wei; Wang, Chunqiu; Zhao, Min
2014-03-01
To ease the burdens on the hospitalization capacity, an emerging swallowable-capsule technology has evolved to serve as a remote gastrointestinal (GI) disease examination technique with the aid of the wireless body sensor network (WBSN). Secure multimedia transmission in such a swallowable-capsule-based WBSN faces critical challenges including energy efficiency and content quality guarantee. In this paper, we propose a joint resource allocation and stream authentication scheme to maintain the best possible video quality while ensuring security and energy efficiency in GI-WBSNs. The contribution of this research is twofold. First, we establish a unique signature-hash (S-H) diversity approach in the authentication domain to optimize video authentication robustness and the authentication bit rate overhead over a wireless channel. Based on the full exploration of S-H authentication diversity, we propose a new two-tier signature-hash (TTSH) stream authentication scheme to improve the video quality by reducing authentication dependence overhead while protecting its integrity. Second, we propose to combine this authentication scheme with a unique S-H oriented unequal resource allocation (URA) scheme to improve the energy-distortion-authentication performance of wireless video delivery in GI-WBSN. Our analysis and simulation results demonstrate that the proposed TTSH with URA scheme achieves considerable gain in both authenticated video quality and energy efficiency.
NASA Astrophysics Data System (ADS)
Pandremmenou, K.; Shahid, M.; Kondi, L. P.; Lövström, B.
2015-03-01
In this work, we propose a No-Reference (NR) bitstream-based model for predicting the quality of H.264/AVC video sequences, affected by both compression artifacts and transmission impairments. The proposed model is based on a feature extraction procedure, where a large number of features are calculated from the packet-loss impaired bitstream. Many of the features are firstly proposed in this work, and the specific set of the features as a whole is applied for the first time for making NR video quality predictions. All feature observations are taken as input to the Least Absolute Shrinkage and Selection Operator (LASSO) regression method. LASSO indicates the most important features, and using only them, it is possible to estimate the Mean Opinion Score (MOS) with high accuracy. Indicatively, we point out that only 13 features are able to produce a Pearson Correlation Coefficient of 0.92 with the MOS. Interestingly, the performance statistics we computed in order to assess our method for predicting the Structural Similarity Index and the Video Quality Metric are equally good. Thus, the obtained experimental results verified the suitability of the features selected by LASSO as well as the ability of LASSO in making accurate predictions through sparse modeling.
Waddell, George; Williamon, Aaron
2017-01-01
Judgments of music performance quality are commonly employed in music practice, education, and research. However, previous studies have demonstrated the limited reliability of such judgments, and there is now evidence that extraneous visual, social, and other “non-musical” features can unduly influence them. The present study employed continuous measurement techniques to examine how the process of forming a music quality judgment is affected by the manipulation of temporally specific visual cues. Video footage comprising an appropriate stage entrance and error-free performance served as the standard condition (Video 1). This footage was manipulated to provide four additional conditions, each identical save for a single variation: an inappropriate stage entrance (Video 2); the presence of an aural performance error midway through the piece (Video 3); the same error accompanied by a negative facial reaction by the performer (Video 4); the facial reaction with no corresponding aural error (Video 5). The participants were 53 musicians and 52 non-musicians (N = 105) who individually assessed the performance quality of one of the five randomly assigned videos via a digital continuous measurement interface and headphones. The results showed that participants viewing the “inappropriate” stage entrance made judgments significantly more quickly than those viewing the “appropriate” entrance, and while the poor entrance caused significantly lower initial scores among those with musical training, the effect did not persist long into the performance. The aural error caused an immediate drop in quality judgments that persisted to a lower final score only when accompanied by the frustrated facial expression from the pianist; the performance error alone caused a temporary drop only in the musicians' ratings, and the negative facial reaction alone caused no reaction regardless of participants' musical experience. These findings demonstrate the importance of visual information in forming evaluative and aesthetic judgments in musical contexts and highlight how visual cues dynamically influence those judgments over time. PMID:28487662
Veterinary students' usage and perception of video teaching resources
2011-01-01
Background The purpose of our study was to use a student-centred approach to develop an online video learning resource (called 'Moo Tube') at the School of Veterinary Medicine and Science, University of Nottingham, UK and also to provide guidance for other academics in the School wishing to develop a similar resource in the future. Methods A focus group in the format of the nominal group technique was used to garner the opinions of 12 undergraduate students (3 from year-1, 4 from year-2 and 5 from year-3). Students generated lists of items in response to key questions, these responses were thematically analysed to generate key themes which were compared between the different year groups. The number of visits to 'Moo Tube' before and after an objective structured practical examination (OSPE) was also analysed to provide data on video usage. Results Students highlighted a number of strengths of video resources which can be grouped into four overarching themes: (1) teaching enhancement, (2) accessibility, (3) technical quality and (4) video content. Of these themes, students rated teaching enhancement and accessibility most highly. Video usage was seen to significantly increase (P < 0.05) prior to an examination and significantly decrease (P < 0.05) following the examination. Conclusions The students had a positive perception of video usage in higher education. Video usage increases prior to practical examinations. Image quality was a greater concern with year-3 students than with either year-1 or 2 students but all groups highlighted the following as important issues: i) good sound quality, ii) accessibility, including location of videos within electronic libraries, and iii) video content. Based on the findings from this study, guidelines are suggested for those developing undergraduate veterinary videos. We believe that many aspects of our list will have resonance in other areas of medicine education and higher education. PMID:21219639
Developing online continuing education content for enhancing caring among Taiwan nurses.
Hsu, Tzu-Chuan; Turton, Michael A; Cheng, Su-Fen; Lee-Hsieh, Jane
2013-04-01
To promote the quality of nursing care, a hospital in Taiwan committed to implementing its SHARE framework for clinical practice. This study was conducted to develop caring content for the SHARE framework in the form of online continuing education videos. Five focus group interviews were conducted with 19 exemplary nurses. A constant comparative method was used to extract caring themes that were integrated into the five components of SHARE: S: Sense patient's needs; H: Help patient out; A: Acknowledge patient's feelings; R: Respect patient's dignity and privacy; E: Explain what is happening. Concrete caring behaviors consistent with SHARE were identified. Real-world scenarios were used to produce five videos demonstrating the components of SHARE for use in online caring education. This project offers a new strategy for strengthening caring behavior in nurse-patient interactions and may help to establish a model for caring in nursing continuing education in Taiwan. Copyright 2013, SLACK Incorporated.
Enhance Video Film using Retnix method
NASA Astrophysics Data System (ADS)
Awad, Rasha; Al-Zuky, Ali A.; Al-Saleh, Anwar H.; Mohamad, Haidar J.
2018-05-01
An enhancement technique used to improve the studied video quality. Algorithms like mean and standard deviation are used as a criterion within this paper, and it applied for each video clip that divided into 80 images. The studied filming environment has different light intensity (315, 566, and 644Lux). This different environment gives similar reality to the outdoor filming. The outputs of the suggested algorithm are compared with the results before applying it. This method is applied into two ways: first, it is applied for the full video clip to get the enhanced film; second, it is applied for every individual image to get the enhanced image then compiler them to get the enhanced film. This paper shows that the enhancement technique gives good quality video film depending on a statistical method, and it is recommended to use it in different application.
NASA Astrophysics Data System (ADS)
Jumisko-Pyykkö, Satu; Häkkinen, Jukka
2008-02-01
In the product development of services it is important to adjust mobile video quality according to the quality requirements of potential users. Therefore, a careful participant selection is very important. However, in the literature the details of participant selection are often handled without great detail. This is also reflected in the handling of experimental results, where the impact of psychographic factors on quality is rarely reported. As the user attributes potentially have a large effect to the results, we investigated the role of various psychographical variables on the subjective evaluation of audiovisual video quality in two different experiments. The studied variables were age, gender, education, professionalism, television consumption, experiences of different digital video qualities, and attitude towards technology. The results showed that quality evaluations were affected by almost all background factors. The most significant variables were age, professionalism, knowledge of digital quality features and attitude towards technology. The knowledge of these factors can be exploited in careful participant selection, which will in turn increase the validity of results as the subjective evaluations reflect better the requirements of potential users.
Gaze-Aware Streaming Solutions for the Next Generation of Mobile VR Experiences.
Lungaro, Pietro; Sjoberg, Rickard; Valero, Alfredo Jose Fanghella; Mittal, Ashutosh; Tollmar, Konrad
2018-04-01
This paper presents a novel approach to content delivery for video streaming services. It exploits information from connected eye-trackers embedded in the next generation of VR Head Mounted Displays (HMDs). The proposed solution aims to deliver high visual quality, in real time, around the users' fixations points while lowering the quality everywhere else. The goal of the proposed approach is to substantially reduce the overall bandwidth requirements for supporting VR video experiences while delivering high levels of user perceived quality. The prerequisites to achieve these results are: (1) mechanisms that can cope with different degrees of latency in the system and (2) solutions that support fast adaptation of video quality in different parts of a frame, without requiring a large increase in bitrate. A novel codec configuration, capable of supporting near-instantaneous video quality adaptation in specific portions of a video frame, is presented. The proposed method exploits in-built properties of HEVC encoders and while it introduces a moderate amount of error, these errors are indetectable by users. Fast adaptation is the key to enable gaze-aware streaming and its reduction in bandwidth. A testbed implementing gaze-aware streaming, together with a prototype HMD with in-built eye tracker, is presented and was used for testing with real users. The studies quantified the bandwidth savings achievable by the proposed approach and characterize the relationships between Quality of Experience (QoE) and network latency. The results showed that up to 83% less bandwidth is required to deliver high QoE levels to the users, as compared to conventional solutions.
Colón-de Martí, Luz N; Rodríguez-Figueroa, Linnette; Nazario, Lelis L; Gutiérrez, Roberto; González, Alexis
2012-01-01
Video games have become a popular entertainment among adolescents. Although some video games are educational, there are others with high content of violence and the potential for other harmful effects. Lack of appropriate supervision of video games use during adolescence, a crucial stage of development, may lead to serious behavioral consequences in some adolescents. There is also concern about time spent playing video games and the subsequent neglect of more developmentally appropriate activities, such as completing academic tasks. Self-administered questionnaires were used to assess video game use patterns and parental supervision among 55 adolescent patients 13-17 years old (mean age 14.4 years; 56.4% males) and their parents. Parental supervision /monitoring of the adolescents video games use was not consistent and gender related differences were found regarding their video game use. Close to one third (32%) of the participants reported video game playing had interfered with their academic performance. Parents who understood video games rating system were more likely to prohibit their use due to rating. These findings underscore the need for clear and consistently enforced rules and monitoring of video games use by adolescents. Parents need to be educated about the relevance of their supervision, video games content and rating system; so they will decrease time playing and exposure to potentially harmful video games. It also supports the relevance of addressing supervision, gender-based parental supervisory styles, and patterns of video games use in the evaluation and treatment of adolescents.
Hsieh, Ting-Chang; Wolfe, Heather; Sutton, Robert; Myers, Sage; Nadkarni, Vinay; Donoghue, Aaron
2015-08-01
To describe chest compression (CC) rate, depth, and leaning during pediatric cardiopulmonary resuscitation (CPR) as measured by two simultaneous methods, and to assess the accuracy and reliability of video review in measuring CC quality. Resuscitations in a pediatric emergency department are videorecorded for quality improvement. Patients aged 8-18 years receiving CPR under videorecording were eligible for inclusion. CPR was recorded by a pressure/accelerometer feedback device and tabulated in 30-s epochs of uninterrupted CC. Investigators reviewed videorecorded CPR and measured rate, depth, and release by observation. Raters categorized epochs as 'meeting criteria' if 80% of CCs in an epoch were done with appropriate depth (>45 mm) and/or release (<2.5 kg leaning). Comparison between device measurement and video was made by Spearman's ρ for rate and by κ statistic for depth and release. Interrater reliability for depth and release was measured by κ statistic. Five patients underwent videorecorded CPR using the feedback device. 97 30-s epochs of CCs were analyzed. CCs met criteria for rate in 74/97 (76%) of epochs; depth in 38/97 (39%); release in 82/97 (84%). Agreement between video and feedback device for rate was good (ρ = 0.77); agreement was poor for depth and release (κ 0.04-0.41). Interrater reliability for depth and release measured by video was poor (κ 0.04-0.49). Video review measured CC rate accurately; depth and release were not reliably or accurately assessed by video. Future research should focus on the optimal combination of methods for measuring CPR quality. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Kim, Young Ju; Xiao, Yan; Hu, Peter; Dutton, Richard
2009-08-01
To understand staff acceptance of a remote video monitoring system for operating room (OR) coordination. Improved real-time remote visual access to OR may enhance situational awareness but also raises privacy concerns for patients and staff. Survey. A system was implemented in a six-room surgical suite to display OR monitoring video at an access restricted control desk area. Image quality was manipulated to improve staff acceptance. Two months after installation, interviews and a survey were conducted on staff acceptance of video monitoring. About half of all OR personnel responded (n = 63). Overall levels of concerns were low, with 53% rated no concerns and 42% little concern. Top two reported uses of the video were to see if cases are finished and to see if a room is ready. Viewing the video monitoring system as useful did not reduce levels of concern. Staff in supervisory positions perceived less concern about the system's impact on privacy than did those supervised (p < 0.03). Concerns for patient privacy correlated with concerns for staff privacy and performance monitoring. Technical means such as manipulating image quality helped staff acceptance. Manipulation of image quality resulted overall acceptance of monitoring video, with residual levels of concerns. OR nurses may express staff privacy concern in the form of concerns over patient privacy. This study provided suggestions for technological and implementation strategies of video monitoring for coordination use in OR. Deployment of communication technology and integration of clinical information will likely raise concerns over staff privacy and performance monitoring. The potential gain of increased information access may be offset by negative impact of a sense of loss of autonomy.
Subjective quality evaluation of low-bit-rate video
NASA Astrophysics Data System (ADS)
Masry, Mark; Hemami, Sheila S.; Osberger, Wilfried M.; Rohaly, Ann M.
2001-06-01
A subjective quality evaluation was performed to qualify vie4wre responses to visual defects that appear in low bit rate video at full and reduced frame rates. The stimuli were eight sequences compressed by three motion compensated encoders - Sorenson Video, H.263+ and a Wavelet based coder - operating at five bit/frame rate combinations. The stimulus sequences exhibited obvious coding artifacts whose nature differed across the three coders. The subjective evaluation was performed using the Single Stimulus Continuos Quality Evaluation method of UTI-R Rec. BT.500-8. Viewers watched concatenated coded test sequences and continuously registered the perceived quality using a slider device. Data form 19 viewers was colleted. An analysis of their responses to the presence of various artifacts across the range of possible coding conditions and content is presented. The effects of blockiness and blurriness on perceived quality are examined. The effects of changes in frame rate on perceived quality are found to be related to the nature of the motion in the sequence.
Lee, Chaewoo
2014-01-01
The advancement in wideband wireless network supports real time services such as IPTV and live video streaming. However, because of the sharing nature of the wireless medium, efficient resource allocation has been studied to achieve a high level of acceptability and proliferation of wireless multimedia. Scalable video coding (SVC) with adaptive modulation and coding (AMC) provides an excellent solution for wireless video streaming. By assigning different modulation and coding schemes (MCSs) to video layers, SVC can provide good video quality to users in good channel conditions and also basic video quality to users in bad channel conditions. For optimal resource allocation, a key issue in applying SVC in the wireless multicast service is how to assign MCSs and the time resources to each SVC layer in the heterogeneous channel condition. We formulate this problem with integer linear programming (ILP) and provide numerical results to show the performance under 802.16 m environment. The result shows that our methodology enhances the overall system throughput compared to an existing algorithm. PMID:25276862
Video Monitoring a Simulation-Based Quality Improvement Program in Bihar, India.
Dyer, Jessica; Spindler, Hilary; Christmas, Amelia; Shah, Malay Bharat; Morgan, Melissa; Cohen, Susanna R; Sterne, Jason; Mahapatra, Tanmay; Walker, Dilys
2018-04-01
Simulation-based training has become an accepted clinical training andragogy in high-resource settings with its use increasing in low-resource settings. Video recordings of simulated scenarios are commonly used by facilitators. Beyond using the videos during debrief sessions, researchers can also analyze the simulation videos to quantify technical and nontechnical skills during simulated scenarios over time. Little is known about the feasibility and use of large-scale systems to video record and analyze simulation and debriefing data for monitoring and evaluation in low-resource settings. This manuscript describes the process of designing and implementing a large-scale video monitoring system. Mentees and Mentors were consented and all simulations and debriefs conducted at 320 Primary Health Centers (PHCs) were video recorded. The system design, number of video recordings, and inter-rater reliability of the coded videos were assessed. The final dataset included a total of 11,278 videos. Overall, a total of 2,124 simulation videos were coded and 183 (12%) were blindly double-coded. For the double-coded sample, the average inter-rater reliability (IRR) scores were 80% for nontechnical skills, and 94% for clinical technical skills. Among 4,450 long debrief videos received, 216 were selected for coding and all were double-coded. Data quality of simulation videos was found to be very good in terms of recorded instances of "unable to see" and "unable to hear" in Phases 1 and 2. This study demonstrates that video monitoring systems can be effectively implemented at scale in resource limited settings. Further, video monitoring systems can play several vital roles within program implementation, including monitoring and evaluation, provision of actionable feedback to program implementers, and assurance of program fidelity.
A Database Design and Development Case: Home Theater Video
ERIC Educational Resources Information Center
Ballenger, Robert; Pratt, Renee
2012-01-01
This case consists of a business scenario of a small video rental store, Home Theater Video, which provides background information, a description of the functional business requirements, and sample data. The case provides sufficient information to design and develop a moderately complex database to assist Home Theater Video in solving their…
Using Behavioral Skills Training and Video Rehearsal to Teach Blackjack Skills
ERIC Educational Resources Information Center
Speelman, Ryan C.; Whiting, Seth W.; Dixon, Mark R.
2015-01-01
A behavioral skills training procedure that consisted of video instructions, video rehearsal, and video testing was used to teach 4 recreational gamblers a specific skill in playing blackjack (sometimes called "card counting"). A multiple baseline design was used to evaluate intervention effects on card-counting accuracy and chips won or…
Video Game Based Learning in English Grammar
ERIC Educational Resources Information Center
Singaravelu, G.
2008-01-01
The study enlightens the effectiveness of Video Game Based Learning in English Grammar at standard VI. A Video Game package was prepared and it consisted of self-learning activities in play way manner which attracted the minds of the young learners. Chief objective: Find out the effectiveness of Video-Game based learning in English grammar.…
Mississippi's New Forestry Best Management Practices Video
Andrew James Londo; John Benkert Auel
2004-01-01
Mississippi's latest version of forestry best management practices (BMPs) for water quality was released in 2000. In conjunction with this release, funds were obtained through a Section 319H grant from the Mississippi Department of Environmental Quality to create a new BMPs video. Additional assistance was obtained from Georgia Pacific, PlumCreek, Weyerhaeuser,...
Toward enhancing the distributed video coder under a multiview video codec framework
NASA Astrophysics Data System (ADS)
Lee, Shih-Chieh; Chen, Jiann-Jone; Tsai, Yao-Hong; Chen, Chin-Hua
2016-11-01
The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.
Transmission of live laparoscopic surgery over the Internet2.
Damore, L J; Johnson, J A; Dixon, R S; Iverson, M A; Ellison, E C; Melvin, W S
1999-11-01
Video broadcasting of surgical procedures is an important tool for education, training, and consultation. Current video conferencing systems are expensive and time-consuming and require preplanning. Real-time Internet video is known for its poor quality and relies on the equipment and the speed of the connection. The Internet2, a new high-speed (up to 2,048 Mbps), large bandwidth data network presently connects more than 100 universities and corporations. We have successfully used the Internet2 to broadcast the first real-time, high-quality audio/video program from a live laparoscopic operation to distant points. Video output of the laparoscopic camera and audio from a wireless microphone were broadcast to distant sites using a proprietary, PC-based implementation of H.320 video conferencing over a TCP/IP network connected to the Internet2. The receiving sites participated in two-way, real-time video and audio communications and graded the quality of the signal they received. On August 25, 1998, a laparoscopic Nissen fundoplication was transmitted to Internet2 stations in Colorado, Pennsylvania, and to an Internet station in New York. On September 28 and 29, 1998, we broadcast laparoscopic operations throughout both days to the Internet2 Fall Conference in San Francisco, California. Most recently, on February 24, 1999, we transmitted a laparoscopic Heller myotomy to the Abilene Network Launch Event in Washington, DC. The Internet2 is currently able to provide the bandwidth needed for a turn-key video conferencing system with high-resolution, real-time transmission. The system could be used for a variety of teaching and educational programs for experienced surgeons, residents, and medical students.
Pressler, Ronit M; Seri, Stefano; Kane, Nick; Martland, Tim; Goyal, Sushma; Iyer, Anand; Warren, Elliott; Notghi, Lesley; Bill, Peter; Thornton, Rachel; Appleton, Richard; Doyle, Sarah; Rushton, Sarah; Worley, Alan; Boyd, Stewart G
2017-08-01
Paediatric Epilepsy surgery in the UK has recently been centralised in order to improve expertise and quality of service available to children. Video EEG monitoring or telemetry is a highly specialised and a crucial component of the pre-surgical evaluation. Although many Epilepsy Monitoring Units work to certain standards, there is no national or international guideline for paediatric video telemetry. Due to lack of evidence we used a modified Delphi process utilizing the clinical and academic expertise of the clinical neurophysiology sub-specialty group of Children's Epilepsy Surgical Service (CESS) centres in England and Wales. This process consisted of the following stages I: Identification of the consensus working group, II: Identification of key areas for guidelines, III: Consensus practice points and IV: Final review. Statements that gained consensus (median score of either 4 or 5 using a five-point Likerttype scale) were included in the guideline. Two rounds of feedback and amendments were undertaken. The consensus guidelines includes the following topics: referral pathways, neurophysiological equipment standards, standards of recording techniques, with specific emphasis on safety of video EEG monitoring both with and without drug withdrawal, a protocol for testing patient's behaviours, data storage and guidelines for writing factual reports and conclusions. All statements developed received a median score of 5 and were adopted by the group. Using a modified Delphi process we were able to develop universally-accepted video EEG guidelines for the UK CESS. Although these recommendations have been specifically developed for the pre-surgical evaluation of children with epilepsy, it is assumed that most components are transferable to any paediatric video EEG monitoring setting. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
ATM Quality of Service Tests for Digitized Video Using ATM Over Satellite: Laboratory Tests
NASA Technical Reports Server (NTRS)
Ivancic, William D.; Brooks, David E.; Frantz, Brian D.
1997-01-01
A digitized video application was used to help determine minimum quality of service parameters for asynchronous transfer mode (ATM) over satellite. For these tests, binomially distributed and other errors were digitally inserted in an intermediate frequency link via a satellite modem and a commercial gaussian noise generator. In this paper, the relation- ship between the ATM cell error and cell loss parameter specifications is discussed with regard to this application. In addition, the video-encoding algorithms, test configurations, and results are presented in detail.
NASA Technical Reports Server (NTRS)
2000-01-01
Video Pics is a software program that generates high-quality photos from video. The software was developed under an SBIR contract with Marshall Space Flight Center by Redhawk Vision, Inc.--a subsidiary of Irvine Sensors Corporation. Video Pics takes information content from multiple frames of video and enhances the resolution of a selected frame. The resulting image has enhanced sharpness and clarity like that of a 35 mm photo. The images are generated as digital files and are compatible with image editing software.
Scientific Library to Hold Annual Winter Video Series | Poster
The Scientific Library is getting ready for its Annual Winter Video Series. Beginning on Monday, January 9 and concluding on Friday, February 17, the Winter Video Series will consist of two different PBS programs, each with three episodes.
Real-Time Internet Connections: Implications for Surgical Decision Making in Laparoscopy
Broderick, Timothy J.; Harnett, Brett M.; Doarn, Charles R.; Rodas, Edgar B.; Merrell, Ronald C.
2001-01-01
Objective To determine whether a low-bandwidth Internet connection can provide adequate image quality to support remote real-time surgical consultation. Summary Background Data Telemedicine has been used to support care at a distance through the use of expensive equipment and broadband communication links. In the past, the operating room has been an isolated environment that has been relatively inaccessible for real-time consultation. Recent technological advances have permitted videoconferencing over low-bandwidth, inexpensive Internet connections. If these connections are shown to provide adequate video quality for surgical applications, low-bandwidth telemedicine will open the operating room environment to remote real-time surgical consultation. Methods Surgeons performing a laparoscopic cholecystectomy in Ecuador or the Dominican Republic shared real-time laparoscopic images with a panel of surgeons at the parent university through a dial-up Internet account. The connection permitted video and audio teleconferencing to support real-time consultation as well as the transmission of real-time images and store-and-forward images for observation by the consultant panel. A total of six live consultations were analyzed. In addition, paired local and remote images were “grabbed” from the video feed during these laparoscopic cholecystectomies. Nine of these paired images were then placed into a Web-based tool designed to evaluate the effect of transmission on image quality. Results The authors showed for the first time the ability to identify critical anatomic structures in laparoscopy over a low-bandwidth connection via the Internet. The consultant panel of surgeons correctly remotely identified biliary and arterial anatomy during six laparoscopic cholecystectomies. Within the Web-based questionnaire, 15 surgeons could not blindly distinguish the quality of local and remote laparoscopic images. Conclusions Low-bandwidth, Internet-based telemedicine is inexpensive, effective, and almost ubiquitous. Use of these inexpensive, portable technologies will allow sharing of surgical procedures and decisions regardless of location. Internet telemedicine consistently supported real-time intraoperative consultation in laparoscopic surgery. The implications are broad with respect to quality improvement and diffusion of knowledge as well as for basic consultation. PMID:11505061
A pragmatic intervention to promote condom use by female sex workers in Thailand.
Ford, N.; Koetsawang, S.
1999-01-01
An overview is presented of a multifaceted intervention to promote consistent condom use by female commercial sex workers in Thailand, in the context of the government's 100% condom use policy for preventing spread of human immunodeficiency virus (HIV) infection. The project is described with reference to a succession of stages including pre-programme needs assessment, intervention design, implementation and evaluation. The key elements of the intervention were video scenarios and discussions coordinated by health personnel, and video-depicted open-ended narratives aimed at helping sex workers to explore their personal and work-related dilemmas and concerns. A core objective was to enhance sex workers' self-esteem and perceived future with a view to strengthening their motivation to take preventive action against HIV infection. The intervention was evaluated using a combination of qualitative (process evaluation) and quantitative (outcome) methods. The outcome evaluation was undertaken using a pretest, post-test intervention and control group quasi-experimental design. There were significant increases in consistent condom use among the intervention groups but not among the controls. Pragmatic stability is advocated for the Thai sex industry and recommendations are offered for good quality HIV prevention activities. PMID:10612884
Gerber, Stephan M; Jeitziner, Marie-Madlen; Wyss, Patric; Chesham, Alvin; Urwyler, Prabitha; Müri, René M; Jakob, Stephan M; Nef, Tobias
2017-10-16
After prolonged stay in an intensive care unit (ICU) patients often complain about cognitive impairments that affect health-related quality of life after discharge. The aim of this proof-of-concept study was to test the feasibility and effects of controlled visual and acoustic stimulation in a virtual reality (VR) setup in the ICU. The VR setup consisted of a head-mounted display in combination with an eye tracker and sensors to assess vital signs. The stimulation consisted of videos featuring natural scenes and was tested in 37 healthy participants in the ICU. The VR stimulation led to a reduction of heart rate (p = 0. 049) and blood pressure (p = 0.044). Fixation/saccade ratio (p < 0.001) was increased when a visual target was presented superimposed on the videos (reduced search activity), reflecting enhanced visual processing. Overall, the VR stimulation had a relaxing effect as shown in vital markers of physical stress and participants explored less when attending the target. Our study indicates that VR stimulation in ICU settings is feasible and beneficial for critically ill patients.
Priority-based methods for reducing the impact of packet loss on HEVC encoded video streams
NASA Astrophysics Data System (ADS)
Nightingale, James; Wang, Qi; Grecos, Christos
2013-02-01
The rapid growth in the use of video streaming over IP networks has outstripped the rate at which new network infrastructure has been deployed. These bandwidth-hungry applications now comprise a significant part of all Internet traffic and present major challenges for network service providers. The situation is more acute in mobile networks where the available bandwidth is often limited. Work towards the standardisation of High Efficiency Video Coding (HEVC), the next generation video coding scheme, is currently on track for completion in 2013. HEVC offers the prospect of a 50% improvement in compression over the current H.264 Advanced Video Coding standard (H.264/AVC) for the same quality. However, there has been very little published research on HEVC streaming or the challenges of delivering HEVC streams in resource-constrained network environments. In this paper we consider the problem of adapting an HEVC encoded video stream to meet the bandwidth limitation in a mobile networks environment. Video sequences were encoded using the Test Model under Consideration (TMuC HM6) for HEVC. Network abstraction layers (NAL) units were packetized, on a one NAL unit per RTP packet basis, and transmitted over a realistic hybrid wired/wireless testbed configured with dynamically changing network path conditions and multiple independent network paths from the streamer to the client. Two different schemes for the prioritisation of RTP packets, based on the NAL units they contain, have been implemented and empirically compared using a range of video sequences, encoder configurations, bandwidths and network topologies. In the first prioritisation method the importance of an RTP packet was determined by the type of picture and the temporal switching point information carried in the NAL unit header. Packets containing parameter set NAL units and video coding layer (VCL) NAL units of the instantaneous decoder refresh (IDR) and the clean random access (CRA) pictures were given the highest priority followed by NAL units containing pictures used as reference pictures from which others can be predicted. The second method assigned a priority to each NAL unit based on the rate-distortion cost of the VCL coding units contained in the NAL unit. The sum of the rate-distortion costs of each coding unit contained in a NAL unit was used as the priority weighting. The preliminary results of extensive experiments have shown that all three schemes offered an improvement in PSNR, when comparing original and decoded received streams, over uncontrolled packet loss. Using the first method consistently delivered a significant average improvement of 0.97dB over the uncontrolled scenario while the second method provided a measurable, but less consistent, improvement across the range of testing conditions and encoder configurations.
Video Surveillance: All Eyes Turn to IP
ERIC Educational Resources Information Center
Raths, David
2011-01-01
Many university officials recognize the need to upgrade their older analog video surveillance systems. In a 2010 survey by "Campus Safety" magazine, half of university respondents expressed dissatisfaction with the quality and coverage of their current video surveillance systems. Among the limitations of analog closed-circuit television…
Use of videos to support teaching and learning of clinical skills in nursing education: A review.
Forbes, Helen; Oprescu, Florin I; Downer, Terri; Phillips, Nicole M; McTier, Lauren; Lord, Bill; Barr, Nigel; Alla, Kristel; Bright, Peter; Dayton, Jeanne; Simbag, Vilma; Visser, Irene
2016-07-01
Information and communications technology is influencing the delivery of education in tertiary institutions. In particular, the increased use of videos for teaching and learning clinical skills in nursing may be a promising direction to pursue, yet we need to better document the current research in this area of inquiry. The aim of this paper was to explore and document the current areas of research into the use of videos to support teaching and learning of clinical skills in nursing education. The four main areas of current and future research are effectiveness, efficiency, usage, and quality of videos as teaching and learning materials. While there is a clear need for additional research in the area, the use of videos seems to be a promising, relevant, and increasingly used instructional strategy that could enhance the quality of clinical skills education. Copyright © 2016 Elsevier Ltd. All rights reserved.
Spatiotemporal video deinterlacing using control grid interpolation
NASA Astrophysics Data System (ADS)
Venkatesan, Ragav; Zwart, Christine M.; Frakes, David H.; Li, Baoxin
2015-03-01
With the advent of progressive format display and broadcast technologies, video deinterlacing has become an important video-processing technique. Numerous approaches exist in the literature to accomplish deinterlacing. While most earlier methods were simple linear filtering-based approaches, the emergence of faster computing technologies and even dedicated video-processing hardware in display units has allowed higher quality but also more computationally intense deinterlacing algorithms to become practical. Most modern approaches analyze motion and content in video to select different deinterlacing methods for various spatiotemporal regions. We introduce a family of deinterlacers that employs spectral residue to choose between and weight control grid interpolation based spatial and temporal deinterlacing methods. The proposed approaches perform better than the prior state-of-the-art based on peak signal-to-noise ratio, other visual quality metrics, and simple perception-based subjective evaluations conducted by human viewers. We further study the advantages of using soft and hard decision thresholds on the visual performance.
Digital codec for real-time processing of broadcast quality video signals at 1.8 bits/pixel
NASA Technical Reports Server (NTRS)
Shalkhauser, Mary JO; Whyte, Wayne A., Jr.
1989-01-01
The authors present the hardware implementation of a digital television bandwidth compression algorithm which processes standard NTSC (National Television Systems Committee) composite color television signals and produces broadcast-quality video in real time at an average of 1.8 b/pixel. The sampling rate used with this algorithm results in 768 samples over the active portion of each video line by 512 active video lines per video frame. The algorithm is based on differential pulse code modulation (DPCM), but additionally utilizes a nonadaptive predictor, nonuniform quantizer, and multilevel Huffman coder to reduce the data rate substantially below that achievable with straight DPCM. The nonadaptive predictor and multilevel Huffman coder combine to set this technique apart from prior-art DPCM encoding algorithms. The authors describe the data compression algorithm and the hardware implementation of the codec and provide performance results.
Video Image Stabilization and Registration (VISAR) Software
NASA Technical Reports Server (NTRS)
1999-01-01
Two scientists at NASA Marshall Space Flight Center, atmospheric scientist Paul Meyer (left) and solar physicist Dr. David Hathaway, have developed promising new software, called Video Image Stabilization and Registration (VISAR), that may help law enforcement agencies to catch criminals by improving the quality of video recorded at crime scenes, VISAR stabilizes camera motion in the horizontal and vertical as well as rotation and zoom effects; produces clearer images of moving objects; smoothes jagged edges; enhances still images; and reduces video noise of snow. VISAR could also have applications in medical and meteorological imaging. It could steady images of Ultrasounds which are infamous for their grainy, blurred quality. It would be especially useful for tornadoes, tracking whirling objects and helping to determine the tornado's wind speed. This image shows two scientists reviewing an enhanced video image of a license plate taken from a moving automobile.
Using Video Modeling to Increase Variation in the Conversation of Children with Autism
ERIC Educational Resources Information Center
Charlop, Marjorie H.; Gilmore, Laura; Chang, Gina T.
2009-01-01
The present study assessed the effects of video modeling on acquisition and generalization of variation in the conversational speech of two boys with autism. A video was made showing several versions of several topics of conversation, thus providing multiple exemplars of each conversation. Video modeling consisted of showing each child a video…
Development and Validation of a Bilingual Stroke Preparedness Assessment Instrument.
Skolarus, Lesli E; Mazor, Kathleen M; Sánchez, Brisa N; Dome, Mackenzie; Biller, José; Morgenstern, Lewis B
2017-04-01
Stroke preparedness interventions are limited by the lack of psychometrically sound intermediate end points. We sought to develop and assess the reliability and validity of the video-Stroke Action Test (video-STAT) an English and a Spanish video-based test to assess people's ability to recognize and react to stroke signs. Video-STAT development and testing was divided into 4 phases: (1) video development and community-generated response options, (2) pilot testing in community health centers, (3) administration in a national sample, bilingual sample, and neurologist sample, and (4) administration before and after a stroke preparedness intervention. The final version of the video-STAT included 8 videos: 4 acute stroke/emergency, 2 prior stroke/nonemergency, 1 nonstroke/emergency, and 1 nonstroke/nonemergency. Acute stroke recognition and action response were queried after each vignette. Video-STAT scoring was based on the acute stroke vignettes only (score range 0-12 best). The national sample consisted of 598 participants, 438 who took the video-STAT in English and 160 who took the video-STAT in Spanish. There was adequate internal consistency (Cronbach α=0.72). The average video-STAT score was 5.6 (SD=3.6), whereas the average neurologist score was 11.4 (SD=1.3). There was no difference in video-STAT scores between the 116 bilingual video-STAT participants who took the video-STAT in English or Spanish. Compared with baseline scores, the video-STAT scores increased after a stroke preparedness intervention (6.2 versus 8.9, P <0.01) among a sample of 101 black adults and youth. The video-STAT yields reliable scores that seem to be valid measures of stroke preparedness. © 2017 American Heart Association, Inc.
Development and Validation of a Bilingual Stroke Preparedness Assessment Instrument
Skolarus, Lesli E.; Mazor, Kathleen M.; Sánchez, Brisa N.; Dome, Mackenzie; Biller, José; Morgenstern, Lewis B.
2017-01-01
Background and Purpose Stroke preparedness interventions are limited by the lack of psychometrically sound intermediate endpoints. We sought to develop and assess the reliability and validity of the video-Stroke Action Test, video-STAT, an English and Spanish video-based test to assess people’s ability to recognize and react to stroke signs. Methods Video-STAT development and testing was divided into four phases: 1) video development and community-generated response options; 2) pilot testing in community health centers; 3) administration in a national sample, bilingual sample and neurologist sample; and 4) administration before and after a stroke preparedness intervention. Results The final version of the video-STAT included 8 videos: 4 acute stroke/emergency, 2 prior stroke/non-emergency, 1 non-stroke/emergency, 1 non-stroke/non-emergency. Acute stroke recognition and action response were queried after each vignette. Video-STAT scoring was based on the acute stroke vignettes only (score range 0–12 best). The national sample consisted of 598 participants, 438 who took the video-STAT in English and 160 who took the video-STAT in Spanish. There was adequate internal consistency (Cronbach’s alpha=0.72). The average video-STAT score was 5.6 (sd=3.6) while the average neurologist score was 11.4 (sd=1.3). There was no difference in video-STAT scores between the 116 bilingual video-STAT participants who took the video-STAT in English or Spanish. Compared to baseline scores, the video-STAT scores increased following a stroke preparedness intervention (6.2 vs. 8.9, p<0.01) among a sample of 101 African American adults and youth. Conclusion The video-STAT yields reliable scores that appear to be valid measures of stroke preparedness. PMID:28250199
Reliability and Validity of the Behavioral Addiction Measure for Video Gaming.
Sanders, James L; Williams, Robert J
2016-01-01
Most tests of video game addiction have weak construct validity and limited ability to correctly identify people in denial. The purpose of the present research was to investigate the reliability and validity of a new test of video game addiction (Behavioral Addiction Measure-Video Gaming [BAM-VG]) that was developed in part to address these deficiencies. Regular adult video gamers (n = 506) were recruited from a Canadian online panel and completed a survey containing three measures of excessive video gaming (BAM-VG; DSM-5 criteria for Internet Gaming Disorder [IGD]; and the IGD-20), as well as questions concerning extensiveness of video game involvement and self-report of problems associated with video gaming. One month later, they were reassessed for the purposes of establishing test-retest reliability. The BAM-VG demonstrated good internal consistency as well as 1 month test-retest reliability. Criterion-related validity was demonstrated by significant correlations with the following: time spent playing, self-identification of video game problems, and scores on other instruments designed to assess video game addiction (DSM-5 IGD, IGD-20). Consistent with the theory, principal component analysis identified two components underlying the BAM-VG that roughly correspond with impaired control and significant negative consequences deriving from this impaired control. Together with its excellent construct validity and other technical features, the BAM-VG represents a reliable and valid test of video game addiction.
ERIC Educational Resources Information Center
Damen, S.; Kef, S.; Worm, M.; Janssen, M. J.; Schuengel, C.
2011-01-01
Background: Individuals in group homes may experience poor quality of social interaction with their professional caregivers, limiting their quality of life. The video-based Contact programme may help caregivers to improve their interaction with clients. Method: Seventy-two caregivers of 12 individuals with visual and intellectual disabilities…
Viewers' perceptions of a YouTube music therapy session video.
Gregory, Dianne; Gooding, Lori G
2013-01-01
Recent research revealed diverse content and varying levels of quality in YouTube music therapy videos and prompted questions about viewers' discrimination abilities. This study compares ratings of a YouTube music therapy session video by viewers with different levels of music therapy expertise to determine video elements related to perceptions of representational quality. Eighty-one participants included 25 novices (freshmen and sophomores in an introductory music therapy course), 25 pre-interns (seniors and equivalency students who had completed all core Music Therapy courses), 26 professionals (MT-BC or MT-BC eligibility) with a mean of 1.75 years of experience, and an expert panel of 5 MT-BC professionals with a mean of 11 years of experience in special education. After viewing a music therapy special education video that in previous research met basic competency criteria and professional standards of the American Music Therapy Association, participants completed a 16-item questionnaire. Novices' ratings were more positive (less discriminating) compared to experienced viewers' neutral or negative ratings. Statistical analysis (ANOVA) of novice, pre-intern, and professional ratings of all items revealed significant differences p, .05) for specific therapy content and for a global rating of representational quality. Experienced viewers' ratings were similar to the expert panel's ratings. Content analysis of viewers' reasons for their representational quality ratings corroborated ratings of therapy-specific content. A video that combines and clearly depicts therapy objectives, client improvement, and the effectiveness of music within a therapeutic intervention best represent the music therapy profession in a public social platform like YouTube.
Benchmarking multimedia performance
NASA Astrophysics Data System (ADS)
Zandi, Ahmad; Sudharsanan, Subramania I.
1998-03-01
With the introduction of faster processors and special instruction sets tailored to multimedia, a number of exciting applications are now feasible on the desktops. Among these is the DVD playback consisting, among other things, of MPEG-2 video and Dolby digital audio or MPEG-2 audio. Other multimedia applications such as video conferencing and speech recognition are also becoming popular on computer systems. In view of this tremendous interest in multimedia, a group of major computer companies have formed, Multimedia Benchmarks Committee as part of Standard Performance Evaluation Corp. to address the performance issues of multimedia applications. The approach is multi-tiered with three tiers of fidelity from minimal to full compliant. In each case the fidelity of the bitstream reconstruction as well as quality of the video or audio output are measured and the system is classified accordingly. At the next step the performance of the system is measured. In many multimedia applications such as the DVD playback the application needs to be run at a specific rate. In this case the measurement of the excess processing power, makes all the difference. All these make a system level, application based, multimedia benchmark very challenging. Several ideas and methodologies for each aspect of the problems will be presented and analyzed.
Mantovani, Giulia; Pifferi, Massimo; Vozzi, Giovanni
2010-06-01
Patients with primary ciliary dyskinesia (PCD) have structural and/or functional alterations of cilia that imply deficits in mucociliary clearance and different respiratory pathologies. A useful indicator for the difficult diagnosis is the ciliary beat frequency (CBF) that is significantly lower in pathological cases than in physiological ones. The CBF computation is not rapid, therefore, the aim of this study is to propose an automated method to evaluate it directly from videos of ciliated cells. The cells are taken from inferior nasal turbinates and videos of ciliary movements are registered and eventually processed by the developed software. The software consists in the extraction of features from videos (written with C++ language) and the computation of the frequency (written with Matlab language). This system was tested both on the samples of nasal cavity and software models, and the results were really promising because in a few seconds, it can compute a reliable frequency if compared with that measured with visual methods. It is to be noticed that the reliability of the computation increases with the quality of acquisition system and especially with the sampling frequency. It is concluded that the developed software could be a useful mean for PCD diagnosis.
Ameling, Jessica M; Auguste, Priscilla; Ephraim, Patti L; Lewis-Boyer, LaPricia; DePasquale, Nicole; Greer, Raquel C; Crews, Deidra C; Powe, Neil R; Rabb, Hamid; Boulware, L Ebony
2012-12-01
Few educational resources have been developed to inform patients' renal replacement therapy (RRT) selection decisions. Patients progressing toward end stage renal disease (ESRD) must decide among multiple treatment options with varying characteristics. Complex information about treatments must be adequately conveyed to patients with different educational backgrounds and informational needs. Decisions about treatment options also require family input, as families often participate in patients' treatment and support patients' decisions. We describe the development, design, and preliminary evaluation of an informational, evidence-based, and patient-and family-centered decision aid for patients with ESRD and varying levels of health literacy, health numeracy, and cognitive function. We designed a decision aid comprising a complementary video and informational handbook. We based our development process on data previously obtained from qualitative focus groups and systematic literature reviews. We simultaneously developed the video and handbook in "stages." For the video, stages included (1) directed interviews with culturally appropriate patients and families and preliminary script development, (2) video production, and (3) screening the video with patients and their families. For the handbook, stages comprised (1) preliminary content design, (2) a mixed-methods pilot study among diverse patients to assess comprehension of handbook material, and (3) screening the handbook with patients and their families. The video and handbook both addressed potential benefits and trade-offs of treatment selections. The 50-minute video consisted of demographically diverse patients and their families describing their positive and negative experiences with selecting a treatment option. The video also incorporated health professionals' testimonials regarding various considerations that might influence patients' and families' treatment selections. The handbook was comprised of written words, pictures of patients and health care providers, and diagrams describing the findings and quality of scientific studies comparing treatments. The handbook text was written at a 4th to 6th grade reading level. Pilot study results demonstrated that a majority of patients could understand information presented in the handbook. Patient and families screening the nearly completed video and handbook reviewed the materials favorably. This rigorously designed decision aid may help patients and families make informed decisions about their treatment options for RRT that are well aligned with their values.
Melbye, Sigurd; Hotvedt, Martin; Bolle, Stein Roald
2014-06-02
Videoconferencing on mobile phones may enhance communication, but knowledge on its quality in various situations is needed before it can be used in medical emergencies. Mobile phones automatically activate loudspeaker functionality during videoconferencing, making calls particularly vulnerable to background noise. The aim of this study was to investigate if videoconferencing can be used between lay bystanders and Emergency Medical Dispatch (EMD) operators for initial emergency calls during medical emergencies, under suboptimal sound and light conditions. Videoconferencing was tested between 90 volunteers and an emergency medical dispatcher in a standardized scenario of a medical emergency. Three different environments were used for the trials: indoors with moderate background noise, outdoors with daylight and much background noise, and outdoors during nighttime with little background noise. Thirty participants were recruited for each of the three locations. After informed consent, each participant was asked to use a video mobile phone to communicate with an EMD operator. During the video call the EMD operator gave instructions for tasks to be performed by the participant. The video quality from the caller to the EMD was evaluated by the EMD operator and rated on a five step scale ranging from "not able to see" to "good video quality". Sound quality between participants and EMD operators was assessed by a method developed for this trial. Kruskal - Wallis and Chi-square tests were used for statistical analysis. Video quality was significantly different between the groups (p <0.001), and the nighttime group had lower video quality. For most sessions in the nighttime group it was still possible to see actions done at the simulated emergency site. All participants were able to perform their tasks according to the instructions given by dispatchers, although with a need for more repetitions during sessions with much background noise. No calls were rated by dispatchers as incomprehensible due to low sound quality and only 3% of the calls were considered somewhat difficult or very difficult to understand. Videoconferencing on mobile phones can be used for the initial emergency call during medical emergencies also in suboptimal conditions.
STS-107 Debris Characterization Using Re-entry Imaging
NASA Technical Reports Server (NTRS)
Raiche, George A.
2009-01-01
Analysis of amateur video of the early reentry phases of the Columbia accident is discussed. With poor video quality and little theoretical guidance, the analysis team estimated mass and acceleration ranges for the debris shedding events observed in the video. Camera calibration and optical performance issues are also described.
Video Measurements: Quantity or Quality
ERIC Educational Resources Information Center
Zajkov, Oliver; Mitrevski, Boce
2012-01-01
Students have problems with understanding, using and interpreting graphs. In order to improve the students' skills for working with graphs, we propose Manual Video Measurement (MVM). In this paper, the MVM method is explained and its accuracy is tested. The comparison with the standardized video data software shows that its accuracy is comparable…
Barbier, Paolo; Alimento, Marina; Berna, Giovanni; Celeste, Fabrizio; Gentile, Francesco; Mantero, Antonio; Montericcio, Vincenzo; Muratori, Manuela
2007-05-01
Large files produced by standard compression algorithms slow down spread of digital and tele-echocardiography. We validated echocardiographic video high-grade compression with the new Motion Pictures Expert Groups (MPEG)-4 algorithms with a multicenter study. Seven expert cardiologists blindly scored (5-point scale) 165 uncompressed and compressed 2-dimensional and color Doppler video clips, based on combined diagnostic content and image quality (uncompressed files as references). One digital video and 3 MPEG-4 algorithms (WM9, MV2, and DivX) were used, the latter at 3 compression levels (0%, 35%, and 60%). Compressed file sizes decreased from 12 to 83 MB to 0.03 to 2.3 MB (1:1051-1:26 reduction ratios). Mean SD of differences was 0.81 for intraobserver variability (uncompressed and digital video files). Compared with uncompressed files, only the DivX mean score at 35% (P = .04) and 60% (P = .001) compression was significantly reduced. At subcategory analysis, these differences were still significant for gray-scale and fundamental imaging but not for color or second harmonic tissue imaging. Original image quality, session sequence, compression grade, and bitrate were all independent determinants of mean score. Our study supports use of MPEG-4 algorithms to greatly reduce echocardiographic file sizes, thus facilitating archiving and transmission. Quality evaluation studies should account for the many independent variables that affect image quality grading.
Koster, Ellen S; Blom, Lyda; Overbeeke, Marloes R; Philbert, Daphne; Vervloet, Marcia; Koopman, Laura; van Dijk, Liset
2016-01-01
Consumer Quality Index questionnaires are used to assess quality of care from patients' experiences. To provide insight into the agreement about quality of pharmaceutical care, measured both by a patient questionnaire and video observations. Pharmaceutical encounters in four pharmacies were video-recorded. Patients completed a questionnaire based upon the Consumer Quality Index Pharmaceutical Care after the encounter containing questions about patients' experiences regarding information provision, medication counseling, and pharmacy staff's communication style. An observation protocol was used to code the recorded encounters. Agreement between video observation and patients' experiences was calculated. In total, 109 encounters were included for analysis. For the domains "medication counseling" and "communication style", agreement between patients' experiences and observations was very high (>90%). Less agreement (45%) was found for "information provision", which was rated more positive by patients compared to the observations, especially for the topic, encouragement of patients' questioning behavior. A questionnaire is useful to assess the quality of medication counseling and pharmacy staff's communication style, but might be less suitable to evaluate information provision and pharmacy staff's encouragement of patients' questioning behavior. Although patients may believe that they have received all necessary information to use their new medicine, some information on specific instructions was not addressed during the encounter. When using questionnaires to get insight into information provision, observations of encounters are very informative to validate the patient questionnaires and make necessary adjustments.
PSQM-based RR and NR video quality metrics
NASA Astrophysics Data System (ADS)
Lu, Zhongkang; Lin, Weisi; Ong, Eeping; Yang, Xiaokang; Yao, Susu
2003-06-01
This paper presents a new and general concept, PQSM (Perceptual Quality Significance Map), to be used in measuring the visual distortion. It makes use of the selectivity characteristic of HVS (Human Visual System) that it pays more attention to certain area/regions of visual signal due to one or more of the following factors: salient features in image/video, cues from domain knowledge, and association of other media (e.g., speech or audio). PQSM is an array whose elements represent the relative perceptual-quality significance levels for the corresponding area/regions for images or video. Due to its generality, PQSM can be incorporated into any visual distortion metrics: to improve effectiveness or/and efficiency of perceptual metrics; or even to enhance a PSNR-based metric. A three-stage PQSM estimation method is also proposed in this paper, with an implementation of motion, texture, luminance, skin-color and face mapping. Experimental results show the scheme can improve the performance of current image/video distortion metrics.
Modeling of video compression effects on target acquisition performance
NASA Astrophysics Data System (ADS)
Cha, Jae H.; Preece, Bradley; Espinola, Richard L.
2009-05-01
The effect of video compression on image quality was investigated from the perspective of target acquisition performance modeling. Human perception tests were conducted recently at the U.S. Army RDECOM CERDEC NVESD, measuring identification (ID) performance on simulated military vehicle targets at various ranges. These videos were compressed with different quality and/or quantization levels utilizing motion JPEG, motion JPEG2000, and MPEG-4 encoding. To model the degradation on task performance, the loss in image quality is fit to an equivalent Gaussian MTF scaled by the Structural Similarity Image Metric (SSIM). Residual compression artifacts are treated as 3-D spatio-temporal noise. This 3-D noise is found by taking the difference of the uncompressed frame, with the estimated equivalent blur applied, and the corresponding compressed frame. Results show good agreement between the experimental data and the model prediction. This method has led to a predictive performance model for video compression by correlating various compression levels to particular blur and noise input parameters for NVESD target acquisition performance model suite.
Temporal consistent depth map upscaling for 3DTV
NASA Astrophysics Data System (ADS)
Schwarz, Sebastian; Sjöström, Mârten; Olsson, Roger
2014-03-01
The ongoing success of three-dimensional (3D) cinema fuels increasing efforts to spread the commercial success of 3D to new markets. The possibilities of a convincing 3D experience at home, such as three-dimensional television (3DTV), has generated a great deal of interest within the research and standardization community. A central issue for 3DTV is the creation and representation of 3D content. Acquiring scene depth information is a fundamental task in computer vision, yet complex and error-prone. Dedicated range sensors, such as the Time of-Flight camera (ToF), can simplify the scene depth capture process and overcome shortcomings of traditional solutions, such as active or passive stereo analysis. Admittedly, currently available ToF sensors deliver only a limited spatial resolution. However, sophisticated depth upscaling approaches use texture information to match depth and video resolution. At Electronic Imaging 2012 we proposed an upscaling routine based on error energy minimization, weighted with edge information from an accompanying video source. In this article we develop our algorithm further. By adding temporal consistency constraints to the upscaling process, we reduce disturbing depth jumps and flickering artifacts in the final 3DTV content. Temporal consistency in depth maps enhances the 3D experience, leading to a wider acceptance of 3D media content. More content in better quality can boost the commercial success of 3DTV.
HealthRecSys: A semantic content-based recommender system to complement health videos.
Sanchez Bocanegra, Carlos Luis; Sevillano Ramos, Jose Luis; Rizo, Carlos; Civit, Anton; Fernandez-Luque, Luis
2017-05-15
The Internet, and its popularity, continues to grow at an unprecedented pace. Watching videos online is very popular; it is estimated that 500 h of video are uploaded onto YouTube, a video-sharing service, every minute and that, by 2019, video formats will comprise more than 80% of Internet traffic. Health-related videos are very popular on YouTube, but their quality is always a matter of concern. One approach to enhancing the quality of online videos is to provide additional educational health content, such as websites, to support health consumers. This study investigates the feasibility of building a content-based recommender system that links health consumers to reputable health educational websites from MedlinePlus for a given health video from YouTube. The dataset for this study includes a collection of health-related videos and their available metadata. Semantic technologies (such as SNOMED-CT and Bio-ontology) were used to recommend health websites from MedlinePlus. A total of 26 healths professionals participated in evaluating 253 recommended links for a total of 53 videos about general health, hypertension, or diabetes. The relevance of the recommended health websites from MedlinePlus to the videos was measured using information retrieval metrics such as the normalized discounted cumulative gain and precision at K. The majority of websites recommended by our system for health videos were relevant, based on ratings by health professionals. The normalized discounted cumulative gain was between 46% and 90% for the different topics. Our study demonstrates the feasibility of using a semantic content-based recommender system to enrich YouTube health videos. Evaluation with end-users, in addition to healthcare professionals, will be required to identify the acceptance of these recommendations in a nonsimulated information-seeking context.
NASA Astrophysics Data System (ADS)
Yang, Xinyan; Zhao, Wei; Ye, Long; Zhang, Qin
2017-07-01
This paper proposes a no-reference objective stereoscopic video quality assessment method with the motivation that making the effect of objective experiments close to that of subjective way. We believe that the image regions with different visual salient degree should not have the same weights when designing an assessment metric. Therefore, we firstly use GBVS algorithm to each frame pairs and separate both the left and right viewing images into the regions with strong, general and week saliency. Besides, local feature information like blockiness, zero-crossing and depth are extracted and combined with a mathematical model to calculate a quality assessment score. Regions with different salient degree are assigned with different weights in the mathematical model. Experiment results demonstrate the superiority of our method compared with the existed state-of-the-art no-reference objective Stereoscopic video quality assessment methods.
Automated content and quality assessment of full-motion-video for the generation of meta data
NASA Astrophysics Data System (ADS)
Harguess, Josh
2015-05-01
Virtually all of the video data (and full-motion-video (FMV)) that is currently collected and stored in support of missions has been corrupted to various extents by image acquisition and compression artifacts. Additionally, video collected by wide-area motion imagery (WAMI) surveillance systems and unmanned aerial vehicles (UAVs) and similar sources is often of low quality or in other ways corrupted so that it is not worth storing or analyzing. In order to make progress in the problem of automatic video analysis, the first problem that should be solved is deciding whether the content of the video is even worth analyzing to begin with. We present a work in progress to address three types of scenes which are typically found in real-world data stored in support of Department of Defense (DoD) missions: no or very little motion in the scene, large occlusions in the scene, and fast camera motion. Each of these produce video that is generally not usable to an analyst or automated algorithm for mission support and therefore should be removed or flagged to the user as such. We utilize recent computer vision advances in motion detection and optical flow to automatically assess FMV for the identification and generation of meta-data (or tagging) of video segments which exhibit unwanted scenarios as described above. Results are shown on representative real-world video data.
NASA Astrophysics Data System (ADS)
Adedayo, Bada; Wang, Qi; Alcaraz Calero, Jose M.; Grecos, Christos
2015-02-01
The recent explosion in video-related Internet traffic has been driven by the widespread use of smart mobile devices, particularly smartphones with advanced cameras that are able to record high-quality videos. Although many of these devices offer the facility to record videos at different spatial and temporal resolutions, primarily with local storage considerations in mind, most users only ever use the highest quality settings. The vast majority of these devices are optimised for compressing the acquired video using a single built-in codec and have neither the computational resources nor battery reserves to transcode the video to alternative formats. This paper proposes a new low-complexity dynamic resource allocation engine for cloud-based video transcoding services that are both scalable and capable of being delivered in real-time. Firstly, through extensive experimentation, we establish resource requirement benchmarks for a wide range of transcoding tasks. The set of tasks investigated covers the most widely used input formats (encoder type, resolution, amount of motion and frame rate) associated with mobile devices and the most popular output formats derived from a comprehensive set of use cases, e.g. a mobile news reporter directly transmitting videos to the TV audience of various video format requirements, with minimal usage of resources both at the reporter's end and at the cloud infrastructure end for transcoding services.
Smartphone based automatic organ validation in ultrasound video.
Vaish, Pallavi; Bharath, R; Rajalakshmi, P
2017-07-01
Telesonography involves transmission of ultrasound video from remote areas to the doctors for getting diagnosis. Due to the lack of trained sonographers in remote areas, the ultrasound videos scanned by these untrained persons do not contain the proper information that is required by a physician. As compared to standard methods for video transmission, mHealth driven systems need to be developed for transmitting valid medical videos. To overcome this problem, we are proposing an organ validation algorithm to evaluate the ultrasound video based on the content present. This will guide the semi skilled person to acquire the representative data from patient. Advancement in smartphone technology allows us to perform high medical image processing on smartphone. In this paper we have developed an Application (APP) for a smartphone which can automatically detect the valid frames (which consist of clear organ visibility) in an ultrasound video and ignores the invalid frames (which consist of no-organ visibility), and produces a compressed sized video. This is done by extracting the GIST features from the Region of Interest (ROI) of the frame and then classifying the frame using SVM classifier with quadratic kernel. The developed application resulted with the accuracy of 94.93% in classifying valid and invalid images.
Video coding for 3D-HEVC based on saliency information
NASA Astrophysics Data System (ADS)
Yu, Fang; An, Ping; Yang, Chao; You, Zhixiang; Shen, Liquan
2016-11-01
As an extension of High Efficiency Video Coding ( HEVC), 3D-HEVC has been widely researched under the impetus of the new generation coding standard in recent years. Compared with H.264/AVC, its compression efficiency is doubled while keeping the same video quality. However, its higher encoding complexity and longer encoding time are not negligible. To reduce the computational complexity and guarantee the subjective quality of virtual views, this paper presents a novel video coding method for 3D-HEVC based on the saliency informat ion which is an important part of Human Visual System (HVS). First of all, the relationship between the current coding unit and its adjacent units is used to adjust the maximum depth of each largest coding unit (LCU) and determine the SKIP mode reasonably. Then, according to the saliency informat ion of each frame image, the texture and its corresponding depth map will be divided into three regions, that is, salient area, middle area and non-salient area. Afterwards, d ifferent quantization parameters will be assigned to different regions to conduct low complexity coding. Finally, the compressed video will generate new view point videos through the renderer tool. As shown in our experiments, the proposed method saves more bit rate than other approaches and achieves up to highest 38% encoding time reduction without subjective quality loss in compression or rendering.
NASA Astrophysics Data System (ADS)
Dorfner, Tobias; Förtsch, Christian; Boone, William; Neuhaus, Birgit J.
2017-09-01
A number of studies on single instructional quality features have been reported for mathematics and science instruction. For summarizing single instructional quality features, researchers have created a model of three basic dimensions (classroom management, supportive climate, and cognitive activation) of instructional quality mainly through observing mathematics instruction. Considering this model as valid for all subjects and as usable for describing instruction, we used it in this study which aimed to analyze characteristics of instructional quality in biology lessons of high-achieving and low-achieving classes, independently of content. Therefore, we used the data of three different previous video studies of biology instruction conducted in Germany. From each video study, we selected three high-achieving and three low-achieving classes (N = 18 teachers; 35 videos) for our multiple-case study, in which conspicuous characteristics of instructional quality features were qualitatively identified and qualitatively analyzed. The amount of these characteristics was counted in a quantitative way in all the videos. The characteristics we found could be categorized using the model of three basic dimensions of instructional quality despite some subject-specific differences for biology instruction. Our results revealed that many more characteristics were observable in high-achieving classes than in low-achieving classes. Thus, we believe that this model could be used to describe biology instruction independently of the content. We also make the claims about the qualities for biology instruction—working with concentration in a content-structured environment, getting challenged in higher order thinking, and getting praised for performance—that could have positive influence on students' achievement.
1981-01-01
Video cameras with contrast and black level controls can yield polarized light and differential interference contrast microscope images with unprecedented image quality, resolution, and recording speed. The theoretical basis and practical aspects of video polarization and differential interference contrast microscopy are discussed and several applications in cell biology are illustrated. These include: birefringence of cortical structures and beating cilia in Stentor, birefringence of rotating flagella on a single bacterium, growth and morphogenesis of echinoderm skeletal spicules in culture, ciliary and electrical activity in a balancing organ of a nudibranch snail, and acrosomal reaction in activated sperm. PMID:6788777
Latest Highlights from our Direct Measurement Video Collection
NASA Astrophysics Data System (ADS)
Vonk, M.; Bohacek, P. H.
2014-12-01
Recent advances in technology have made videos much easier to produce, edit, store, transfer, and view. This has spawned an explosion in a production of a wide variety of different types of pedagogical videos. But with the exception of student-made videos (which are often of poor quality) almost all of the educational videos being produced are passive. No matter how compelling the content, students are expected to simply sit and watch them. Because we feel that being engaged and active are necessary components of student learning, we have been working to create a free online library of Direct Measurement Videos (DMV's). These videos are short high-quality videos of real events, shot in a way that allows students to make measurements directly from the video. Instead of handing students a word problem about a car skidding on ice, we actually show them the car skidding on ice. We then ask them to measure the important quantities, make calculations based on those measurements and solve for unknowns. DMV's are more interesting than their word problem equivalents and frequently inspire further questions about the physics of the situation or about the uncertainty of the measurement in ways that word problems almost never do. We feel that it is simply impossible to a video of a roller coaster or a rocket and then argue that word problems are better. In this talk I will highlight some new additions to our DMV collection. This work is supported by NSF TUES award #1245268
JPEG XS-based frame buffer compression inside HEVC for power-aware video compression
NASA Astrophysics Data System (ADS)
Willème, Alexandre; Descampe, Antonin; Rouvroy, Gaël.; Pellegrin, Pascal; Macq, Benoit
2017-09-01
With the emergence of Ultra-High Definition video, reference frame buffers (FBs) inside HEVC-like encoders and decoders have to sustain huge bandwidth. The power consumed by these external memory accesses accounts for a significant share of the codec's total consumption. This paper describes a solution to significantly decrease the FB's bandwidth, making HEVC encoder more suitable for use in power-aware applications. The proposed prototype consists in integrating an embedded lightweight, low-latency and visually lossless codec at the FB interface inside HEVC in order to store each reference frame as several compressed bitstreams. As opposed to previous works, our solution compresses large picture areas (ranging from a CTU to a frame stripe) independently in order to better exploit the spatial redundancy found in the reference frame. This work investigates two data reuse schemes namely Level-C and Level-D. Our approach is made possible thanks to simplified motion estimation mechanisms further reducing the FB's bandwidth and inducing very low quality degradation. In this work, we integrated JPEG XS, the upcoming standard for lightweight low-latency video compression, inside HEVC. In practice, the proposed implementation is based on HM 16.8 and on XSM 1.1.2 (JPEG XS Test Model). Through this paper, the architecture of our HEVC with JPEG XS-based frame buffer compression is described. Then its performance is compared to HM encoder. Compared to previous works, our prototype provides significant external memory bandwidth reduction. Depending on the reuse scheme, one can expect bandwidth and FB size reduction ranging from 50% to 83.3% without significant quality degradation.
Screen Violence and Youth Behavior.
Anderson, Craig A; Bushman, Brad J; Bartholow, Bruce D; Cantor, Joanne; Christakis, Dimitri; Coyne, Sarah M; Donnerstein, Edward; Brockmyer, Jeanne Funk; Gentile, Douglas A; Green, C Shawn; Huesmann, Rowell; Hummer, Tom; Krahé, Barbara; Strasburger, Victor C; Warburton, Wayne; Wilson, Barbara J; Ybarra, Michele
2017-11-01
Violence in screen entertainment media (ie, television, film, video games, and the Internet), defined as depictions of characters (or players) trying to physically harm other characters (or players), is ubiquitous. The Workgroup on Media Violence and Violent Video Games reviewed numerous meta-analyses and other relevant research from the past 60 years, with an emphasis on violent video game research. Consistent with every major science organization review, the Workgroup found compelling evidence of short-term harmful effects, as well as evidence of long-term harmful effects. The vast majority of laboratory-based experimental studies have revealed that violent media exposure causes increased aggressive thoughts, angry feelings, physiologic arousal, hostile appraisals, aggressive behavior, and desensitization to violence and decreases prosocial behavior (eg, helping others) and empathy. Still, to more fully understand the potential for long-term harm from media violence exposure, the field is greatly in need of additional large-sample, high-quality, longitudinal studies that include validated measures of media violence exposure and measures of other known violence risk factors. Also, although several high-quality media violence intervention studies have been conducted, larger-scale studies with more comprehensive and longer-term assessments are needed to fully understand long-term effects and to inform the development of tools that will help to reduce problems associated with aggression and violence. The evidence that violent screen media constitutes a causal risk factor for increased aggression is compelling. Modern social-cognitive theories of social behavior provide useful frameworks for understanding how and why these effects occur. Copyright © 2017 by the American Academy of Pediatrics.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kim, Anthony; Ravi, Ananth
2014-08-15
High dose rate (HDR) remote afterloading brachytherapy involves sending a small, high-activity radioactive source attached to a cable to different positions within a hollow applicator implanted in the patient. It is critical that the source position within the applicator and the dwell time of the source are accurate. Daily quality assurance (QA) tests of the positional and dwell time accuracy are essential to ensure that the accuracy of the remote afterloader is not compromised prior to patient treatment. Our centre has developed an automated, video-based QA system for HDR brachytherapy that is dramatically superior to existing diode or film QAmore » solutions in terms of cost, objectivity, positional accuracy, with additional functionalities such as being able to determine source dwell time and transit time of the source. In our system, a video is taken of the brachytherapy source as it is sent out through a position check ruler, with the source visible through a clear window. Using a proprietary image analysis algorithm, the source position is determined with respect to time as it moves to different positions along the check ruler. The total material cost of the video-based system was under $20, consisting of a commercial webcam and adjustable stand. The accuracy of the position measurement is ±0.2 mm, and the time resolution is 30 msec. Additionally, our system is capable of robustly verifying the source transit time and velocity (a test required by the AAPM and CPQR recommendations), which is currently difficult to perform accurately.« less
Review of the Effectiveness of Video Media in Instruction
1993-04-01
did beginners . This is consistent with the finding that directing attention to the relevant aspect of the video is more effective, because more...abstract or theoretical concepts with animated flowcharts or diagrams (Riches, 1990). Enhancing Practice. Animation can be used within interactive video and
NASA Astrophysics Data System (ADS)
Flores, Eileen; Yelamos, Oriol; Cordova, Miguel; Kose, Kivanc; Phillips, William; Rossi, Anthony; Nehal, Kishwer; Rajadhyaksha, Milind
2017-02-01
Reflectance confocal microscopy (RCM) imaging shows promise for guiding surgical treatment of skin cancers. Recent technological advancements such as the introduction of the handheld version of the reflectance confocal microscope, video acquisition and video-mosaicing have improved RCM as an emerging tool to evaluate cancer margins during routine surgical skin procedures such as Mohs micrographic surgery (MMS). Detection of residual non-melanoma skin cancer (NMSC) tumor during MMS is feasible, as demonstrated by the introduction of real-time perioperative imaging on patients in the surgical setting. Our study is currently testing the feasibility of a new mosaicing algorithm for perioperative RCM imaging of NMSC cancer margins on patients during MMS. We report progress toward imaging and image analysis on forty-five patients, who presented for MMS at the MSKCC Dermatology service. The first 10 patients were used as a training set to establish an RCM imaging algorithm, which was implemented on the remaining test set of 35 patients. RCM imaging, using 35% AlCl3 for nuclear contrast, was performed pre- and intra-operatively with the Vivascope 3000 (Caliber ID). Imaging was performed in quadrants in the wound, to simulate the Mohs surgeon's examination of pathology. Videos were taken at the epidermal and deep dermal margins. Our Mohs surgeons assessed all videos and video-mosaics for quality and correlation to histology. Overall, our RCM video-mosaicing algorithm is feasible. RCM videos and video-mosaics of the epidermal and dermal margins were found to be of clinically acceptable quality. Assessment of cancer margins was affected by type of NMSC, size and location. Among the test set of 35 patients, 83% showed acceptable imaging quality, resolution and contrast. Visualization of nuclear and cellular morphology of residual BCC/SCC tumor and normal skin features could be detected in the peripheral and deep dermal margins. We observed correlation between the RCM videos/video-mosaics and the corresponding histology in 32 lesions. Peri-operative RCM imaging shows promise for improved and faster detection of cancer margins and guiding MMS in the surgical setting.
Statistical analysis of subjective preferences for video enhancement
NASA Astrophysics Data System (ADS)
Woods, Russell L.; Satgunam, PremNandhini; Bronstad, P. Matthew; Peli, Eli
2010-02-01
Measuring preferences for moving video quality is harder than for static images due to the fleeting and variable nature of moving video. Subjective preferences for image quality can be tested by observers indicating their preference for one image over another. Such pairwise comparisons can be analyzed using Thurstone scaling (Farrell, 1999). Thurstone (1927) scaling is widely used in applied psychology, marketing, food tasting and advertising research. Thurstone analysis constructs an arbitrary perceptual scale for the items that are compared (e.g. enhancement levels). However, Thurstone scaling does not determine the statistical significance of the differences between items on that perceptual scale. Recent papers have provided inferential statistical methods that produce an outcome similar to Thurstone scaling (Lipovetsky and Conklin, 2004). Here, we demonstrate that binary logistic regression can analyze preferences for enhanced video.
Application of Bayesian a Priori Distributions for Vehicles' Video Tracking Systems
NASA Astrophysics Data System (ADS)
Mazurek, Przemysław; Okarma, Krzysztof
Intelligent Transportation Systems (ITS) helps to improve the quality and quantity of many car traffic parameters. The use of the ITS is possible when the adequate measuring infrastructure is available. Video systems allow for its implementation with relatively low cost due to the possibility of simultaneous video recording of a few lanes of the road at a considerable distance from the camera. The process of tracking can be realized through different algorithms, the most attractive algorithms are Bayesian, because they use the a priori information derived from previous observations or known limitations. Use of this information is crucial for improving the quality of tracking especially for difficult observability conditions, which occur in the video systems under the influence of: smog, fog, rain, snow and poor lighting conditions.
ERIC Educational Resources Information Center
Haynes, Leonard Stanley
This thesis describes work done as part of the Video Console Indexing Project (VICI), a program to improve the quality and reduce the time and work involved in indexing documents. The objective of the work described was to design a video terminal system which could be connected to a main computer to provide rapid natural communication between the…
47 CFR 76.55 - Definitions applicable to the must-carry rules.
Code of Federal Regulations, 2011 CFR
2011-10-01
... SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.55... responsible for the costs of delivering to the cable system a signal of good quality or a baseband video... terminals of the signal processing equipment, or a baseband video signal. (e) Television market. (1) Until...
47 CFR 76.55 - Definitions applicable to the must-carry rules.
Code of Federal Regulations, 2014 CFR
2014-10-01
... SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.55... responsible for the costs of delivering to the cable system a signal of good quality or a baseband video... terminals of the signal processing equipment, or a baseband video signal. (e) Television market. (1) Until...
47 CFR 76.55 - Definitions applicable to the must-carry rules.
Code of Federal Regulations, 2012 CFR
2012-10-01
... SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.55... responsible for the costs of delivering to the cable system a signal of good quality or a baseband video... terminals of the signal processing equipment, or a baseband video signal. (e) Television market. (1) Until...
47 CFR 76.55 - Definitions applicable to the must-carry rules.
Code of Federal Regulations, 2013 CFR
2013-10-01
... SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.55... responsible for the costs of delivering to the cable system a signal of good quality or a baseband video... terminals of the signal processing equipment, or a baseband video signal. (e) Television market. (1) Until...
Converting laserdisc video to digital video: a demonstration project using brain animations.
Jao, C S; Hier, D B; Brint, S U
1995-01-01
Interactive laserdiscs are of limited value in large group learning situations due to the expense of establishing multiple workstations. The authors implemented an alternative to laserdisc video by using indexed digital video combined with an expert system. High-quality video was captured from a laserdisc player and combined with waveform audio into an audio-video-interleave (AVI) file format in the Microsoft Video-for-Windows environment (Microsoft Corp., Seattle, WA). With the use of an expert system, a knowledge-based computer program provided random access to these indexed AVI files. The program can be played on any multimedia computer without the need for laserdiscs. This system offers a high level of interactive video without the overhead and cost of a laserdisc player.
Global motion compensated visual attention-based video watermarking
NASA Astrophysics Data System (ADS)
Oakes, Matthew; Bhowmik, Deepayan; Abhayaratne, Charith
2016-11-01
Imperceptibility and robustness are two key but complementary requirements of any watermarking algorithm. Low-strength watermarking yields high imperceptibility but exhibits poor robustness. High-strength watermarking schemes achieve good robustness but often suffer from embedding distortions resulting in poor visual quality in host media. This paper proposes a unique video watermarking algorithm that offers a fine balance between imperceptibility and robustness using motion compensated wavelet-based visual attention model (VAM). The proposed VAM includes spatial cues for visual saliency as well as temporal cues. The spatial modeling uses the spatial wavelet coefficients while the temporal modeling accounts for both local and global motion to arrive at the spatiotemporal VAM for video. The model is then used to develop a video watermarking algorithm, where a two-level watermarking weighting parameter map is generated from the VAM saliency maps using the saliency model and data are embedded into the host image according to the visual attentiveness of each region. By avoiding higher strength watermarking in the visually attentive region, the resulting watermarked video achieves high perceived visual quality while preserving high robustness. The proposed VAM outperforms the state-of-the-art video visual attention methods in joint saliency detection and low computational complexity performance. For the same embedding distortion, the proposed visual attention-based watermarking achieves up to 39% (nonblind) and 22% (blind) improvement in robustness against H.264/AVC compression, compared to existing watermarking methodology that does not use the VAM. The proposed visual attention-based video watermarking results in visual quality similar to that of low-strength watermarking and a robustness similar to those of high-strength watermarking.
Lee, Chang Kyu; Kim, Youngjun; Lee, Nam; Kim, Byeongwoo; Kim, Doyoung; Yi, Seong
2017-02-15
Study for feasibility of commercially available action cameras in recording video of spine. Recent innovation of the wearable action camera with high-definition video recording enables surgeons to use camera in the operation at ease without high costs. The purpose of this study is to compare the feasibility, safety, and efficacy of commercially available action cameras in recording video of spine surgery. There are early reports of medical professionals using Google Glass throughout the hospital, Panasonic HX-A100 action camera, and GoPro. This study is the first report for spine surgery. Three commercially available cameras were tested: GoPro Hero 4 Silver, Google Glass, and Panasonic HX-A100 action camera. Typical spine surgery was selected for video recording; posterior lumbar laminectomy and fusion. Three cameras were used by one surgeon and video was recorded throughout the operation. The comparison was made on the perspective of human factor, specification, and video quality. The most convenient and lightweight device for wearing and holding throughout the long operation time was Google Glass. The image quality; all devices except Google Glass supported HD format and GoPro has unique 2.7K or 4K resolution. Quality of video resolution was best in GoPro. Field of view, GoPro can adjust point of interest, field of view according to the surgery. Narrow FOV option was the best for recording in GoPro to share the video clip. Google Glass has potentials by using application programs. Connectivity such as Wi-Fi and Bluetooth enables video streaming for audience, but only Google Glass has two-way communication feature in device. Action cameras have the potential to improve patient safety, operator comfort, and procedure efficiency in the field of spinal surgery and broadcasting a surgery with development of the device and applied program in the future. N/A.
Butler, Stacey J; Lee, Annemarie L; Goldstein, Roger S; Brooks, Dina
2018-02-26
Exercise is an effective treatment for reducing symptom severity and improving quality of life for patients with chronic respiratory diseases. Active video games offer a new and enjoyable way to exercise and have gained popularity in a rehabilitation setting. However, it is unclear whether they achieve comparable physiological and clinical effects as traditional exercise training. A systematic literature search was performed to identify studies that included an active video game component as a form of exercise training and a comparator group in chronic respiratory disease. Two assessors independently reviewed study quality using the Cochrane risk of bias tool and extracted data for exercise capacity, quality of life, and preference of exercise model. Six studies were included in this review. Because of the heterogeneity of the populations, study designs, length of intervention, and outcome measures, meta-analysis could not be performed. Active video game training resulted in comparable training maximal heart rate and dyspnea levels to those achieved when exercising using a treadmill or cycle (n = 5). There was insufficient evidence (n = 3) to determine whether active video game training improved exercise capacity as measured by 6-min walk test or treadmill endurance walking. Although the quality of evidence was low, in a small number of studies active video games induced peak heart rates and dyspnea levels comparable with traditional exercise training. Larger and longer-term randomized controlled trials are needed to establish the impact of video game training for individuals with chronic respiratory diseases.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.
NASA Technical Reports Server (NTRS)
1996-01-01
Optivision developed two PC-compatible boards and associated software under a Goddard Space Flight Center Small Business Innovation Research grant for NASA applications in areas such as telerobotics, telesciences and spaceborne experimentation. From this technology, the company used its own funds to develop commercial products, the OPTIVideo MPEG Encoder and Decoder, which are used for realtime video compression and decompression. They are used in commercial applications including interactive video databases and video transmission. The encoder converts video source material to a compressed digital form that can be stored or transmitted, and the decoder decompresses bit streams to provide high quality playback.
A systematic review of usability test metrics for mobile video streaming apps
NASA Astrophysics Data System (ADS)
Hussain, Azham; Mkpojiogu, Emmanuel O. C.
2016-08-01
This paper presents the results of a systematic review regarding the usability test metrics for mobile video streaming apps. In the study, 238 studies were found, but only 51 relevant papers were eventually selected for the review. The study reveals that time taken for video streaming and the video quality were the two most popular metrics used in the usability tests for mobile video streaming apps. Besides, most of the studies concentrated on the usability of mobile TV as users are switching from traditional TV to mobile TV.
Economic Delivery of Video Teletraining.
ERIC Educational Resources Information Center
Sand, Mary; Chandler, Nick
1995-01-01
Discusses video teletraining as an alternative to traditional classroom education in terms of cost and program effectiveness; understanding the technology; support required to develop and deliver quality instruction; and the instructional design. (AEF)
Koster, Ellen S; Blom, Lyda; Overbeeke, Marloes R; Philbert, Daphne; Vervloet, Marcia; Koopman, Laura; van Dijk, Liset
2016-01-01
Introduction Consumer Quality Index questionnaires are used to assess quality of care from patients’ experiences. Objective To provide insight into the agreement about quality of pharmaceutical care, measured both by a patient questionnaire and video observations. Methods Pharmaceutical encounters in four pharmacies were video-recorded. Patients completed a questionnaire based upon the Consumer Quality Index Pharmaceutical Care after the encounter containing questions about patients’ experiences regarding information provision, medication counseling, and pharmacy staff’s communication style. An observation protocol was used to code the recorded encounters. Agreement between video observation and patients’ experiences was calculated. Results In total, 109 encounters were included for analysis. For the domains “medication counseling” and “communication style”, agreement between patients’ experiences and observations was very high (>90%). Less agreement (45%) was found for “information provision”, which was rated more positive by patients compared to the observations, especially for the topic, encouragement of patients’ questioning behavior. Conclusion A questionnaire is useful to assess the quality of medication counseling and pharmacy staff’s communication style, but might be less suitable to evaluate information provision and pharmacy staff’s encouragement of patients’ questioning behavior. Although patients may believe that they have received all necessary information to use their new medicine, some information on specific instructions was not addressed during the encounter. When using questionnaires to get insight into information provision, observations of encounters are very informative to validate the patient questionnaires and make necessary adjustments. PMID:27042025
Ipsiroglu, Osman S.; Hung, Yi-Hsuan Amy; Chan, Forson; Ross, Michelle L.; Veer, Dorothee; Soo, Sonja; Ho, Gloria; Berger, Mai; McAllister, Graham; Garn, Heinrich; Kloesch, Gerhard; Barbosa, Adriano Vilela; Stockler, Sylvia; McKellin, William; Vatikiotis-Bateson, Eric
2015-01-01
Introduction: Advanced video technology is available for sleep-laboratories. However, low-cost equipment for screening in the home setting has not been identified and tested, nor has a methodology for analysis of video recordings been suggested. Methods: We investigated different combinations of hardware/software for home-videosomnography (HVS) and established a process for qualitative and quantitative analysis of HVS-recordings. A case vignette (HVS analysis for a 5.5-year-old girl with major insomnia and several co-morbidities) demonstrates how methodological considerations were addressed and how HVS added value to clinical assessment. Results: We suggest an “ideal set of hardware/software” that is reliable, affordable (∼$500) and portable (=2.8 kg) to conduct non-invasive HVS, which allows time-lapse analyses. The equipment consists of a net-book, a camera with infrared optics, and a video capture device. (1) We present an HVS-analysis protocol consisting of three steps of analysis at varying replay speeds: (a) basic overview and classification at 16× normal speed; (b) second viewing and detailed descriptions at 4–8× normal speed, and (c) viewing, listening, and in-depth descriptions at real-time speed. (2) We also present a custom software program that facilitates video analysis and note-taking (Annotator©), and Optical Flow software that automatically quantifies movement for internal quality control of the HVS-recording. The case vignette demonstrates how the HVS-recordings revealed the dimension of insomnia caused by restless legs syndrome, and illustrated the cascade of symptoms, challenging behaviors, and resulting medications. Conclusion: The strategy of using HVS, although requiring validation and reliability testing, opens the floor for a new “observational sleep medicine,” which has been useful in describing discomfort-related behavioral movement patterns in patients with communication difficulties presenting with challenging/disruptive sleep/wake behaviors. PMID:25852578
Qualitative Video Analysis of Track-Cycling Team Pursuit in World-Class Athletes.
Sigrist, Samuel; Maier, Thomas; Faiss, Raphael
2017-11-01
Track-cycling team pursuit (TP) is a highly technical effort involving 4 athletes completing 4 km from a standing start, often in less than 240 s. Transitions between athletes leading the team are obviously of utmost importance. To perform qualitative video analyses of transitions of world-class athletes in TP competitions. Videos captured at 100 Hz were recorded for 77 races (including 96 different athletes) in 5 international track-cycling competitions (eg, UCI World Cups and World Championships) and analyzed for the 12 best teams in the UCI Track Cycling TP Olympic ranking. During TP, 1013 transitions were evaluated individually to extract quantitative (eg, average lead time, transition number, length, duration, height in the curve) and qualitative (quality of transition start, quality of return at the back of the team, distance between third and returning rider score) variables. Determination of correlation coefficients between extracted variables and end time allowed assessment of relationships between variables and relevance of the video analyses. Overall quality of transitions and end time were significantly correlated (r = .35, P = .002). Similarly, transition distance (r = .26, P = .02) and duration (r = .35, P = .002) were positively correlated with end time. Conversely, no relationship was observed between transition number, average lead time, or height reached in the curve and end time. Video analysis of TP races highlights the importance of quality transitions between riders, with preferably swift and short relays rather than longer lead times for faster race times.
ERIC Educational Resources Information Center
Calandra, Brendan; Brantley-Dias, Laurie; Yerby, Johnathan; Demir, Kadir
2018-01-01
A group of preservice science teachers edited video footage of their practice teaching to identify and isolate critical incidents. They then wrote guided reflection papers on those critical incidents using different forms of media prompts while they wrote. The authors used a counterbalanced research design to compare the quality of writing that…
Chinese Language Video Clips. [CD-ROM].
ERIC Educational Resources Information Center
Fleming, Stephen; Hipley, David; Ning, Cynthia
This compact disc includes video clips covering six topics for the learner of Chinese: personal information, commercial transactions, travel and leisure, health and sports, food and school. Filmed on location in Beijing, these naturalistic video clips consist mainly of unrehearsed interviews of ordinary people. The learner is lead through a series…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-06
... video programming and apparatus closed captioning requirements. This notice is consistent with the Order... Delivered Using Internet Protocol, and Apparatus Closed Caption Requirements. Form Number: N/A. Respondents... rules governing the closed captioning capabilities of certain apparatus on which consumers view video...
Video Salient Object Detection via Fully Convolutional Networks.
Wang, Wenguan; Shen, Jianbing; Shao, Ling
This paper proposes a deep learning model to efficiently detect salient regions in videos. It addresses two important issues: 1) deep video saliency model training with the absence of sufficiently large and pixel-wise annotated video data and 2) fast video saliency training and detection. The proposed deep video saliency network consists of two modules, for capturing the spatial and temporal saliency information, respectively. The dynamic saliency model, explicitly incorporating saliency estimates from the static saliency model, directly produces spatiotemporal saliency inference without time-consuming optical flow computation. We further propose a novel data augmentation technique that simulates video training data from existing annotated image data sets, which enables our network to learn diverse saliency information and prevents overfitting with the limited number of training videos. Leveraging our synthetic video data (150K video sequences) and real videos, our deep video saliency model successfully learns both spatial and temporal saliency cues, thus producing accurate spatiotemporal saliency estimate. We advance the state-of-the-art on the densely annotated video segmentation data set (MAE of .06) and the Freiburg-Berkeley Motion Segmentation data set (MAE of .07), and do so with much improved speed (2 fps with all steps).This paper proposes a deep learning model to efficiently detect salient regions in videos. It addresses two important issues: 1) deep video saliency model training with the absence of sufficiently large and pixel-wise annotated video data and 2) fast video saliency training and detection. The proposed deep video saliency network consists of two modules, for capturing the spatial and temporal saliency information, respectively. The dynamic saliency model, explicitly incorporating saliency estimates from the static saliency model, directly produces spatiotemporal saliency inference without time-consuming optical flow computation. We further propose a novel data augmentation technique that simulates video training data from existing annotated image data sets, which enables our network to learn diverse saliency information and prevents overfitting with the limited number of training videos. Leveraging our synthetic video data (150K video sequences) and real videos, our deep video saliency model successfully learns both spatial and temporal saliency cues, thus producing accurate spatiotemporal saliency estimate. We advance the state-of-the-art on the densely annotated video segmentation data set (MAE of .06) and the Freiburg-Berkeley Motion Segmentation data set (MAE of .07), and do so with much improved speed (2 fps with all steps).
NASA Astrophysics Data System (ADS)
Al-Hayani, Nazar; Al-Jawad, Naseer; Jassim, Sabah A.
2014-05-01
Video compression and encryption became very essential in a secured real time video transmission. Applying both techniques simultaneously is one of the challenges where the size and the quality are important in multimedia transmission. In this paper we proposed a new technique for video compression and encryption. Both encryption and compression are based on edges extracted from the high frequency sub-bands of wavelet decomposition. The compression algorithm based on hybrid of: discrete wavelet transforms, discrete cosine transform, vector quantization, wavelet based edge detection, and phase sensing. The compression encoding algorithm treats the video reference and non-reference frames in two different ways. The encryption algorithm utilized A5 cipher combined with chaotic logistic map to encrypt the significant parameters and wavelet coefficients. Both algorithms can be applied simultaneously after applying the discrete wavelet transform on each individual frame. Experimental results show that the proposed algorithms have the following features: high compression, acceptable quality, and resistance to the statistical and bruteforce attack with low computational processing.
Twelve tips for reducing production time and increasing long-term usability of instructional video.
Norman, Marie K
2017-08-01
The use of instructional video is increasing across all disciplines and levels of education. Although video has a number of distinct advantages for course delivery and student learning, it can also be time-consuming and resource-intensive to produce, which imposes a burden on busy faculty. With video poised to play a larger role in medical education, we need strategies for streamlining video production and ensuring that the video we produce is of lasting value. This article draws on learning research and best practices in educational technology, along with the author's experience in online education and video production. It offers 12 practical tips for reducing the initial time investment in video production and creating video that can be reused long into the future. These tips can help faculty and departments create high-quality instructional video while using their time and resources more wisely.
Ahlander, Britt-Marie; Engvall, Jan; Maret, Eva; Ericsson, Elisabeth
2018-03-01
To evaluate the effect of video information given before cardiovascular magnetic resonance imaging on patient anxiety and to compare patient experiences of cardiovascular magnetic resonance imaging versus myocardial perfusion scintigraphy. To evaluate whether additional information has an impact on motion artefacts. Cardiovascular magnetic resonance imaging and myocardial perfusion scintigraphy are technically advanced methods for the evaluation of heart diseases. Although cardiovascular magnetic resonance imaging is considered to be painless, patients may experience anxiety due to the closed environment. A prospective randomised intervention study, not registered. The sample (n = 148) consisted of 97 patients referred for cardiovascular magnetic resonance imaging, randomised to receive either video information in addition to standard text-information (CMR-video/n = 49) or standard text-information alone (CMR-standard/n = 48). A third group undergoing myocardial perfusion scintigraphy (n = 51) was compared with the cardiovascular magnetic resonance imaging-standard group. Anxiety was evaluated before, immediately after the procedure and 1 week later. Five questionnaires were used: Cardiac Anxiety Questionnaire, State-Trait Anxiety Inventory, Hospital Anxiety and Depression scale, MRI Fear Survey Schedule and the MRI-Anxiety Questionnaire. Motion artefacts were evaluated by three observers, blinded to the information given. Data were collected between April 2015-April 2016. The study followed the CONSORT guidelines. The CMR-video group scored lower (better) than the cardiovascular magnetic resonance imaging-standard group in the factor Relaxation (p = .039) but not in the factor Anxiety. Anxiety levels were lower during scintigraphic examinations compared to the CMR-standard group (p < .001). No difference was found regarding motion artefacts between CMR-video and CMR-standard. Patient ability to relax during cardiovascular magnetic resonance imaging increased by adding video information prior the exam, which is important in relation to perceived quality in nursing. No effect was seen on motion artefacts. Video information prior to examinations can be an easy and time effective method to help patients cooperate in imaging procedures. © 2017 John Wiley & Sons Ltd.
Sensor and Video Monitoring of Water Quality at Bristol Floating Harbour
NASA Astrophysics Data System (ADS)
Chen, Yiheng; Han, Dawei
2017-04-01
Water system is an essential component in a smart city for its sustainability and resilience. The harbourside is a focal area of Bristol with new buildings and features redeveloped in the last ten years, attracting numerous visitors by the diversity of attractions and beautiful views. There is a strong relationship between the satisfactory of the visitors and local people with the water quality in the Harbour. The freshness and beauty of the water body would please people as well as benefit the aquatic ecosystems. As we are entering a data-rich era, this pilot project aims to explore the concept of using video cameras and smart sensors to collect and monitor water quality condition at the Bristol harbourside. The video cameras and smart sensors are connected to the Bristol Is Open network, an open programmable city platform. This will be the first attempt to collect water quality data in real time in the Bristol urban area with the wireless network. The videos and images of the water body collected by the cameras will be correlated with the in-situ water quality parameters for research purposes. The successful implementation of the sensors can attract more academic researchers and industrial partners to expand the sensor network to multiple locations around the city covering the other parts of the Harbour and River Avon, leading to a new generation of urban system infrastructure model.
Method and Apparatus for Evaluating the Visual Quality of Processed Digital Video Sequences
NASA Technical Reports Server (NTRS)
Watson, Andrew B. (Inventor)
2002-01-01
A Digital Video Quality (DVQ) apparatus and method that incorporate a model of human visual sensitivity to predict the visibility of artifacts. The DVQ method and apparatus are used for the evaluation of the visual quality of processed digital video sequences and for adaptively controlling the bit rate of the processed digital video sequences without compromising the visual quality. The DVQ apparatus minimizes the required amount of memory and computation. The input to the DVQ apparatus is a pair of color image sequences: an original (R) non-compressed sequence, and a processed (T) sequence. Both sequences (R) and (T) are sampled, cropped, and subjected to color transformations. The sequences are then subjected to blocking and discrete cosine transformation, and the results are transformed to local contrast. The next step is a time filtering operation which implements the human sensitivity to different time frequencies. The results are converted to threshold units by dividing each discrete cosine transform coefficient by its respective visual threshold. At the next stage the two sequences are subtracted to produce an error sequence. The error sequence is subjected to a contrast masking operation, which also depends upon the reference sequence (R). The masked errors can be pooled in various ways to illustrate the perceptual error over various dimensions, and the pooled error can be converted to a visual quality measure.
ERIC Educational Resources Information Center
Curby, Timothy W.; Johnson, Price; Mashburn, Andrew J.; Carlis, Lydia
2016-01-01
When conducting classroom observations, researchers are often confronted with the decision of whether to conduct observations live or by using pre-recorded video. The present study focuses on comparing and contrasting observations of live and video administrations of the Classroom Assessment Scoring System-PreK (CLASS-PreK). Associations between…
Pre-processing SAR image stream to facilitate compression for transport on bandwidth-limited-link
Rush, Bobby G.; Riley, Robert
2015-09-29
Pre-processing is applied to a raw VideoSAR (or similar near-video rate) product to transform the image frame sequence into a product that resembles more closely the type of product for which conventional video codecs are designed, while sufficiently maintaining utility and visual quality of the product delivered by the codec.
Implementation and Analysis of Real-Time Streaming Protocols.
Santos-González, Iván; Rivero-García, Alexandra; Molina-Gil, Jezabel; Caballero-Gil, Pino
2017-04-12
Communication media have become the primary way of interaction thanks to the discovery and innovation of many new technologies. One of the most widely used communication systems today is video streaming, which is constantly evolving. Such communications are a good alternative to face-to-face meetings, and are therefore very useful for coping with many problems caused by distance. However, they suffer from different issues such as bandwidth limitation, network congestion, energy efficiency, cost, reliability and connectivity. Hence, the quality of service and the quality of experience are considered the two most important issues for this type of communication. This work presents a complete comparative study of two of the most used protocols of video streaming, Real Time Streaming Protocol (RTSP) and the Web Real-Time Communication (WebRTC). In addition, this paper proposes two new mobile applications that implement those protocols in Android whose objective is to know how they are influenced by the aspects that most affect the streaming quality of service, which are the connection establishment time and the stream reception time. The new video streaming applications are also compared with the most popular video streaming applications for Android, and the experimental results of the analysis show that the developed WebRTC implementation improves the performance of the most popular video streaming applications with respect to the stream packet delay.
Nair, Akshay Gopinathan; Kamal, Saurabh; Dave, Tarjani Vivek; Mishra, Kapil; Reddy, Harsha S; Della Rocca, David; Della Rocca, Robert C; Andron, Aleza; Jain, Vandana
2015-10-01
To study the utility of a commercially available small, portable ultra-high definition (HD) camera (GoPro Hero 4) for intraoperative recording. A head mount was used to fix the camera on the operating surgeon's head. Due care was taken to protect the patient's identity. The recorded video was subsequently edited and used as a teaching tool. This retrospective, noncomparative study was conducted at three tertiary eye care centers. The surgeries recorded were ptosis correction, ectropion correction, dacryocystorhinostomy, angular dermoid excision, enucleation, blepharoplasty and lid tear repair surgery (one each). The recorded videos were reviewed, edited, and checked for clarity, resolution, and reproducibility. The recorded videos were found to be high quality, which allowed for zooming and visualization of the surgical anatomy clearly. Minimal distortion is a drawback that can be effectively addressed during postproduction. The camera, owing to its lightweight and small size, can be mounted on the surgeon's head, thus offering a unique surgeon point-of-view. In our experience, the results were of good quality and reproducible. A head-mounted ultra-HD video recording system is a cheap, high quality, and unobtrusive technique to record surgery and can be a useful teaching tool in external facial and ophthalmic plastic surgery.
Nair, Akshay Gopinathan; Kamal, Saurabh; Dave, Tarjani Vivek; Mishra, Kapil; Reddy, Harsha S; Rocca, David Della; Rocca, Robert C Della; Andron, Aleza; Jain, Vandana
2015-01-01
Objective: To study the utility of a commercially available small, portable ultra-high definition (HD) camera (GoPro Hero 4) for intraoperative recording. Methods: A head mount was used to fix the camera on the operating surgeon's head. Due care was taken to protect the patient's identity. The recorded video was subsequently edited and used as a teaching tool. This retrospective, noncomparative study was conducted at three tertiary eye care centers. The surgeries recorded were ptosis correction, ectropion correction, dacryocystorhinostomy, angular dermoid excision, enucleation, blepharoplasty and lid tear repair surgery (one each). The recorded videos were reviewed, edited, and checked for clarity, resolution, and reproducibility. Results: The recorded videos were found to be high quality, which allowed for zooming and visualization of the surgical anatomy clearly. Minimal distortion is a drawback that can be effectively addressed during postproduction. The camera, owing to its lightweight and small size, can be mounted on the surgeon's head, thus offering a unique surgeon point-of-view. In our experience, the results were of good quality and reproducible. Conclusions: A head-mounted ultra-HD video recording system is a cheap, high quality, and unobtrusive technique to record surgery and can be a useful teaching tool in external facial and ophthalmic plastic surgery. PMID:26655001
Concept-oriented indexing of video databases: toward semantic sensitive retrieval and browsing.
Fan, Jianping; Luo, Hangzai; Elmagarmid, Ahmed K
2004-07-01
Digital video now plays an important role in medical education, health care, telemedicine and other medical applications. Several content-based video retrieval (CBVR) systems have been proposed in the past, but they still suffer from the following challenging problems: semantic gap, semantic video concept modeling, semantic video classification, and concept-oriented video database indexing and access. In this paper, we propose a novel framework to make some advances toward the final goal to solve these problems. Specifically, the framework includes: 1) a semantic-sensitive video content representation framework by using principal video shots to enhance the quality of features; 2) semantic video concept interpretation by using flexible mixture model to bridge the semantic gap; 3) a novel semantic video-classifier training framework by integrating feature selection, parameter estimation, and model selection seamlessly in a single algorithm; and 4) a concept-oriented video database organization technique through a certain domain-dependent concept hierarchy to enable semantic-sensitive video retrieval and browsing.
Background-Modeling-Based Adaptive Prediction for Surveillance Video Coding.
Zhang, Xianguo; Huang, Tiejun; Tian, Yonghong; Gao, Wen
2014-02-01
The exponential growth of surveillance videos presents an unprecedented challenge for high-efficiency surveillance video coding technology. Compared with the existing coding standards that were basically developed for generic videos, surveillance video coding should be designed to make the best use of the special characteristics of surveillance videos (e.g., relative static background). To do so, this paper first conducts two analyses on how to improve the background and foreground prediction efficiencies in surveillance video coding. Following the analysis results, we propose a background-modeling-based adaptive prediction (BMAP) method. In this method, all blocks to be encoded are firstly classified into three categories. Then, according to the category of each block, two novel inter predictions are selectively utilized, namely, the background reference prediction (BRP) that uses the background modeled from the original input frames as the long-term reference and the background difference prediction (BDP) that predicts the current data in the background difference domain. For background blocks, the BRP can effectively improve the prediction efficiency using the higher quality background as the reference; whereas for foreground-background-hybrid blocks, the BDP can provide a better reference after subtracting its background pixels. Experimental results show that the BMAP can achieve at least twice the compression ratio on surveillance videos as AVC (MPEG-4 Advanced Video Coding) high profile, yet with a slightly additional encoding complexity. Moreover, for the foreground coding performance, which is crucial to the subjective quality of moving objects in surveillance videos, BMAP also obtains remarkable gains over several state-of-the-art methods.
YouTube as an educational tool regarding male urethral catheterization.
Nason, Gregory J; Kelly, Padraig; Kelly, Michael E; Burke, Matthew J; Aslam, Asadullah; Giri, Subhasis K; Flood, Hugh D
2015-04-01
Urethral catheterization (UC) is a common procedure carried out on a daily basis. The aims of this study were to assess the quality of YouTube as an educational tool regarding male UC and to assess the experience of newly qualified doctors regarding UC. YouTube was searched for videos containing relevant information about male UC. A checklist for evaluating content for male UC was devised. The top-ranked video was shown to interns and they were questioned regarding their experience of UC and the usefulness of the video. A total of 100 videos was screened and 49 unique videos were identified. The median length of video was 7 min 15 s (range 1 min 44 s to 26 min 44 s). Regarding the Safe Catheter Insertion Score, the mean score was 5.18 ± 1.64. 9 (18.4%) deemed useful, 24 (49%) somewhat useful and 16 (32.7%) not useful. There was no difference in the number of views (p = 0.487), duration of video (p = 0.364) or number of days online (p = 0.123) between those categorized as useful, somewhat useful and not useful. Twenty-six interns (89.7%) attended the UC teaching session. All reported the video to be a useful educational adjunct. Nine of the respondents (42.9%) had independently inserted a urinary catheter before the educational session. The quality of videos on YouTube regarding male UC is widely variable. Preselected videos are deemed useful by junior doctors regarding male UC and can be used as an educational adjunct before performing hands-on tasks.
Video Game Use in the Treatment of Amblyopia: Weighing the Risks of Addiction.
Xu, Chaoying S; Chen, Jessica S; Adelman, Ron A
2015-09-01
Video games have surged in popularity due to their entertainment factor and, with recent innovation, their use in health care. This review explores the dual facets of video games in treating vision impairment in amblyopia as well as their potential for overuse and addiction. Specifically, this review examines video game addiction from a biopsychosocial perspective and relates the addictive qualities of video games with their use as a therapeutic treatment for amblyopia. Current literature supports both the identification of video game addiction as a disease, as well as the therapeutic potential of video games in clinical trials. We show the need for clinicians to be aware of the dangers associated with video game overuse and the need for future studies to examine the risks associated with their health care benefits.
High efficiency video coding for ultrasound video communication in m-health systems.
Panayides, A; Antoniou, Z; Pattichis, M S; Pattichis, C S; Constantinides, A G
2012-01-01
Emerging high efficiency video compression methods and wider availability of wireless network infrastructure will significantly advance existing m-health applications. For medical video communications, the emerging video compression and network standards support low-delay and high-resolution video transmission, at the clinically acquired resolution and frame rates. Such advances are expected to further promote the adoption of m-health systems for remote diagnosis and emergency incidents in daily clinical practice. This paper compares the performance of the emerging high efficiency video coding (HEVC) standard to the current state-of-the-art H.264/AVC standard. The experimental evaluation, based on five atherosclerotic plaque ultrasound videos encoded at QCIF, CIF, and 4CIF resolutions demonstrates that 50% reductions in bitrate requirements is possible for equivalent clinical quality.
Deblocking of mobile stereo video
NASA Astrophysics Data System (ADS)
Azzari, Lucio; Gotchev, Atanas; Egiazarian, Karen
2012-02-01
Most of candidate methods for compression of mobile stereo video apply block-transform based compression based on the H-264 standard with quantization of transform coefficients driven by quantization parameter (QP). The compression ratio and the resulting bit rate are directly determined by the QP level and high compression is achieved for the price of visually noticeable blocking artifacts. Previous studies on perceived quality of mobile stereo video have revealed that blocking artifacts are the most annoying and most influential in the acceptance/rejection of mobile stereo video and can even completely cancel the 3D effect and the corresponding quality added value. In this work, we address the problem of deblocking of mobile stereo video. We modify a powerful non-local transform-domain collaborative filtering method originally developed for denoising of images and video. The method employs grouping of similar block patches residing in spatial and temporal vicinity of a reference block in filtering them collaboratively in a suitable transform domain. We study the most suitable way of finding similar patches in both channels of stereo video and suggest a hybrid four-dimensional transform to process the collected synchronized (stereo) volumes of grouped blocks. The results benefit from the additional correlation available between the left and right channel of the stereo video. Furthermore, addition sharpening is applied through an embedded alpha-rooting in transform domain, which improve the visual appearance of the deblocked frames.
Subjective evaluation of mobile 3D video content: depth range versus compression artifacts
NASA Astrophysics Data System (ADS)
Jumisko-Pyykkö, Satu; Haustola, Tomi; Boev, Atanas; Gotchev, Atanas
2011-02-01
Mobile 3D television is a new form of media experience, which combines the freedom of mobility with the greater realism of presenting visual scenes in 3D. Achieving this combination is a challenging task as greater viewing experience has to be achieved with the limited resources of the mobile delivery channel such as limited bandwidth and power constrained handheld player. This challenge sets need for tight optimization of the overall mobile 3DTV system. Presence of depth and compression artifacts in the played 3D video are two major factors that influence viewer's subjective quality of experience and satisfaction. The primary goal of this study has been to examine the influence of varying depth and compression artifacts on the subjective quality of experience for mobile 3D video content. In addition, the influence of the studied variables on simulator sickness symptoms has been studied and vocabulary-based descriptive quality of experience has been conducted for a sub-set of variables in order to understand the perceptual characteristics in detail. In the experiment, 30 participants have evaluated the overall quality of different 3D video contents with varying depth ranges and compressed with varying quantization parameters. The test video content has been presented on a portable autostereoscopic LCD display with horizontal double density pixel arrangement. The results of the psychometric study indicate that compression artifacts are a dominant factor determining the quality of experience compared to varying depth range. More specifically, contents with strong compression has been rejected by the viewers and deemed unacceptable. The results of descriptive study confirm the dominance of visible spatial artifacts along the added value of depth for artifact-free content. The level of visual discomfort has been determined as not offending.
1999-06-01
Two scientists at NASA Marshall Space Flight Center, atmospheric scientist Paul Meyer (left) and solar physicist Dr. David Hathaway, have developed promising new software, called Video Image Stabilization and Registration (VISAR), that may help law enforcement agencies to catch criminals by improving the quality of video recorded at crime scenes, VISAR stabilizes camera motion in the horizontal and vertical as well as rotation and zoom effects; produces clearer images of moving objects; smoothes jagged edges; enhances still images; and reduces video noise of snow. VISAR could also have applications in medical and meteorological imaging. It could steady images of Ultrasounds which are infamous for their grainy, blurred quality. It would be especially useful for tornadoes, tracking whirling objects and helping to determine the tornado's wind speed. This image shows two scientists reviewing an enhanced video image of a license plate taken from a moving automobile.
NASA Technical Reports Server (NTRS)
White, Preston A., III
1994-01-01
The Operational Television system at Kennedy Space Center operates hundreds of video cameras, many remotely controllable, in support of the operations at the center. This study was undertaken to determine if commercial NABTS (North American Basic Teletext System) teletext transmission in the vertical blanking interval of the genlock signals distributed to the cameras could be used to send remote control commands to the cameras and the associated pan and tilt platforms. Wavelength division multiplexed fiberoptic links are being installed in the OTV system to obtain RS-250 short-haul quality. It was demonstrated that the NABTS transmission could be sent over the fiberoptic cable plant without excessive video quality degradation and that video cameras could be controlled using NABTS transmissions over multimode fiberoptic paths as long as 1.2 km.
Quality evaluation of motion-compensated edge artifacts in compressed video.
Leontaris, Athanasios; Cosman, Pamela C; Reibman, Amy R
2007-04-01
Little attention has been paid to an impairment common in motion-compensated video compression: the addition of high-frequency (HF) energy as motion compensation displaces blocking artifacts off block boundaries. In this paper, we employ an energy-based approach to measure this motion-compensated edge artifact, using both compressed bitstream information and decoded pixels. We evaluate the performance of our proposed metric, along with several blocking and blurring metrics, on compressed video in two ways. First, ordinal scales are evaluated through a series of expectations that a good quality metric should satisfy: the objective evaluation. Then, the best performing metrics are subjectively evaluated. The same subjective data set is finally used to obtain interval scales to gain more insight. Experimental results show that we accurately estimate the percentage of the added HF energy in compressed video.
Dutta, Rahul; Yoon, Renai; Patel, Roshan M; Spradling, Kyle; Okhunov, Zhamshid; Sohn, William; Lee, Hak J; Landman, Jaime; Clayman, Ralph V
2017-06-01
To compare conventional videocystoscopy (CVC) with a novel and affordable (approximately $45) mobile cystoscopy system, the Endockscope (ES). We evaluated the ES system using both fluid (Endockscope-Fluid [ES-F]) and air (Endockscope-Air [ES-A]) to fill the bladder in an effort to expand the global range of flexible cystoscopy. The ES system comprised a portable 1000 lumen LED self-contained cordless light source and a three-dimensional printed adaptor that connects a mobile phone to a flexible fiber-optic cystoscope. Patients undergoing in-office cystoscopic evaluation for either stent removal or bladder cancer surveillance received three examinations: conventional, ES-F, and ES-A cystoscopy. Videos of each examination were recorded and analyzed by expert endoscopists for image quality/resolution, brightness, color quality, sharpness, overall quality, and whether or not they were acceptable for diagnostic purposes. Six of the 10 patients for whom the conventional videos were 100% acceptable for diagnostic purposes were included in our analysis. The conventional videos scored higher on every metric relative to both the ES-F and ES-A videos (p < 0.05). There was no difference between ES-F and ES-A videos on any metric. Fifty-two percent and 44% of the ES-F and ES-A videos, respectively, were considered acceptable for diagnostic purposes (p = 0.384). The ES mobile cystoscopy system may be a reasonable option in settings where electricity, sterile fluid irrigant, or access to CVC equipment is unavailable.
Aykut, Aslan; Kukner, Amber Senel; Karasu, Bugra; Palancıglu, Yeliz; Atmaca, Fatih; Aydogan, Tumay
2018-01-22
Usage of YouTube as an educational tool is gaining attention in academic research. To date, there has been no study on the content and quality of eye surgery videos on YouTube. The aim of this study was to analyze YouTube videos on phacoemulsification in eyes with small pupil. We searched for the phrases "small pupil cataract surgery," "small pupil phacoemulsification," "small pupil cataract surgery complications," and "small pupil phacoemulsification complications" in January 2015. Each resulting video was evaluated by all authors, and Krippendorff's alpha was calculated to measure agreement. Videos were classified according to pupil size (small/very small) in the beginning of the surgery, and whether pupillary diameter was large enough to continue surgery safely after pupillary dilation by the surgeon in the video (safe/not safe). Methods of dilatation were also analyzed. Any stated ocular comorbidity or surgical complications were noted. A total of 96 videos were reviewed. No mechanical intervention for pupillary dilatation was performed in 46 videos. Fifty-eight operated eyes had no stated ocular comorbidity. Ninety-five operations ended successfully without major complication. There was fair agreement between the evaluators regarding pupil sizes (Kα = 0.670) but poor agreement regarding safety (Kα = 0.337). YouTube videos on small pupil phacoemulsification have low complication rates when compared to the literature, although no reliable mechanical dilatation methods are used in almost half of these videos. Until YouTube's place in e-learning becomes clearer, we suggest that viewers be cautious regarding small pupil phacoemulsification videos on YouTube.
Mid-urethral slings on YouTube: quality information on the internet?
Larouche, Maryse; Geoffrion, Roxana; Lazare, Darren; Clancy, Aisling; Lee, Terry; Koenig, Nicole A; Cundiff, Geoffrey W; Stothers, Lynn
2016-06-01
Scant literature exists about the quality of urogynecological content on social media. Our objective was to measure the accuracy and comprehensiveness of YouTube videos related to mid-urethral sling (MUS) procedures. YouTube was searched using the terms "mid-urethral sling," "vaginal tape," "TVT," "TOT," "TVT surgery," and "TOT surgery." Duplicates and videos with less than 1,000 views were excluded. We developed a standardized questionnaire for this project, assessing each video's target audience, main purpose, relevance, informed consent elements, surgical steps, and bias. The primary outcome was the presence of all elements of informed consent. Inter-rater reliability (IRR) was calculated using the Fleiss' kappa statistic. Descriptive statistics were also obtained. Five reviewers each rated 56 videos. Mean IRR was moderate (Fleiss' kappa 0.58 ± 0.24). Video content was classified as physician educational material (67.9 %), patient information (16.1 %), advertisement (10.7 %), lawsuit recruitment (1.8 %), and unclear (3.6 %). MUS was the primary topic for 82.1 % of the videos. The remainder discussed other types of anti-incontinence procedures or prolapse surgery. None of the videos mentioned all four elements of informed consent. Of 32 videos demonstrating surgical technique, none showed the complete list of pre-determined surgical steps. The mean number of listed steps was 7.6/16. Only four videos mentioned at least one post-operative patient instruction. A marketing element was shown in 26.8 % of videos. Patient information about MUS on YouTube is lacking and often biased. Physicians and students viewing YouTube videos for educational purposes should be cognizant of the variability in the surgical steps demonstrated.
Moral license in video games: when being right can mean doing wrong.
Ellithorpe, Morgan E; Cruz, Carlos; Velez, John A; Ewoldsen, David R; Bogert, Adam K
2015-04-01
Research on video game violence has found largely consistent evidence that violence in video games tends to be associated with an increase in antisocial behavior. However, this body of work has mostly ignored one prominent feature of many violent games: moral decision making. It is possible that the influence of video game violence could change when moral decisions are brought into the context. One way video games change behavior is through changes in players' self-perceptions, a process called identity simulation. In addition, a perspective called moral license predicts that these effects should not necessarily be consistent across behaviors, in that people should try to balance selfishness with keeping the moral high ground across many behaviors. Therefore, moral choices (or immoral choices) in a video game may predict less moral (or more moral) behaviors right after the game. However, later behavior may revert yet again, creating a cycle of pro- and antisocial behaviors. The present experiment asks participants to make moral choices in a video game, and then measures their behavior on two subsequent tasks. Results indicate that taking what participants perceive to be the more moral mind-set in the video game predicts more antisocial behavior on the first task, but more pro-social behavior on the next task. These results support identity simulation and moral license processes in a video game and moral behavior context, and indicate that there may be greater complexity in video game violence effects than previously understood.
A streaming-based solution for remote visualization of 3D graphics on mobile devices.
Lamberti, Fabrizio; Sanna, Andrea
2007-01-01
Mobile devices such as Personal Digital Assistants, Tablet PCs, and cellular phones have greatly enhanced user capability to connect to remote resources. Although a large set of applications are now available bridging the gap between desktop and mobile devices, visualization of complex 3D models is still a task hard to accomplish without specialized hardware. This paper proposes a system where a cluster of PCs, equipped with accelerated graphics cards managed by the Chromium software, is able to handle remote visualization sessions based on MPEG video streaming involving complex 3D models. The proposed framework allows mobile devices such as smart phones, Personal Digital Assistants (PDAs), and Tablet PCs to visualize objects consisting of millions of textured polygons and voxels at a frame rate of 30 fps or more depending on hardware resources at the server side and on multimedia capabilities at the client side. The server is able to concurrently manage multiple clients computing a video stream for each one; resolution and quality of each stream is tailored according to screen resolution and bandwidth of the client. The paper investigates in depth issues related to latency time, bit rate and quality of the generated stream, screen resolutions, as well as frames per second displayed.
Borras-Morell, Jose-Enrique; Martinez-Millana, Antonio; Karlsen, Randi
2017-01-01
Health consumers are increasingly using the Internet to search for health information. The existence of overloaded, inaccurate, obsolete, or simply incorrect health information available on the Internet is a serious obstacle for finding relevant and good-quality data that actually helps patients. Search engines of multimedia Internet platforms are thought to help users to find relevant information according to their search. But, is the information recovered by those search engines from quality sources? Is the health information uploaded from reliable sources, such as hospitals and health organizations, easily available to patients? The availability of videos is directly related to the ranking position in YouTube search. The higher the ranking of the information is, the more accessible it is. The aim of this study is to analyze the ranking evolution of diabetes health videos on YouTube in order to discover how videos from reliable channels, such as hospitals and health organizations, are evolving in the ranking. The analysis was done by tracking the ranking of 2372 videos on a daily basis during a 30-day period using 20 diabetes-related queries. Our conclusions are that the current YouTube algorithm favors the presence of reliable videos in upper rank positions in diabetes-related searches. PMID:28243314
Fernandez-Llatas, Carlos; Traver, Vicente; Borras-Morell, Jose-Enrique; Martinez-Millana, Antonio; Karlsen, Randi
2017-01-01
Health consumers are increasingly using the Internet to search for health information. The existence of overloaded, inaccurate, obsolete, or simply incorrect health information available on the Internet is a serious obstacle for finding relevant and good-quality data that actually helps patients. Search engines of multimedia Internet platforms are thought to help users to find relevant information according to their search. But, is the information recovered by those search engines from quality sources? Is the health information uploaded from reliable sources, such as hospitals and health organizations, easily available to patients? The availability of videos is directly related to the ranking position in YouTube search. The higher the ranking of the information is, the more accessible it is. The aim of this study is to analyze the ranking evolution of diabetes health videos on YouTube in order to discover how videos from reliable channels, such as hospitals and health organizations, are evolving in the ranking. The analysis was done by tracking the ranking of 2372 videos on a daily basis during a 30-day period using 20 diabetes-related queries. Our conclusions are that the current YouTube algorithm favors the presence of reliable videos in upper rank positions in diabetes-related searches.
Dynamic frame resizing with convolutional neural network for efficient video compression
NASA Astrophysics Data System (ADS)
Kim, Jaehwan; Park, Youngo; Choi, Kwang Pyo; Lee, JongSeok; Jeon, Sunyoung; Park, JeongHoon
2017-09-01
In the past, video codecs such as vc-1 and H.263 used a technique to encode reduced-resolution video and restore original resolution from the decoder for improvement of coding efficiency. The techniques of vc-1 and H.263 Annex Q are called dynamic frame resizing and reduced-resolution update mode, respectively. However, these techniques have not been widely used due to limited performance improvements that operate well only under specific conditions. In this paper, video frame resizing (reduced/restore) technique based on machine learning is proposed for improvement of coding efficiency. The proposed method features video of low resolution made by convolutional neural network (CNN) in encoder and reconstruction of original resolution using CNN in decoder. The proposed method shows improved subjective performance over all the high resolution videos which are dominantly consumed recently. In order to assess subjective quality of the proposed method, Video Multi-method Assessment Fusion (VMAF) which showed high reliability among many subjective measurement tools was used as subjective metric. Moreover, to assess general performance, diverse bitrates are tested. Experimental results showed that BD-rate based on VMAF was improved by about 51% compare to conventional HEVC. Especially, VMAF values were significantly improved in low bitrate. Also, when the method is subjectively tested, it had better subjective visual quality in similar bit rate.
Compression performance comparison in low delay real-time video for mobile applications
NASA Astrophysics Data System (ADS)
Bivolarski, Lazar
2012-10-01
This article compares the performance of several current video coding standards in the conditions of low-delay real-time in a resource constrained environment. The comparison is performed using the same content and the metrics and mix of objective and perceptual quality metrics. The metrics results in different coding schemes are analyzed from a point of view of user perception and quality of service. Multiple standards are compared MPEG-2, MPEG4 and MPEG-AVC and well and H.263. The metrics used in the comparison include SSIM, VQM and DVQ. Subjective evaluation and quality of service are discussed from a point of view of perceptual metrics and their incorporation in the coding scheme development process. The performance and the correlation of results are presented as a predictor of the performance of video compression schemes.
Visual saliency-based fast intracoding algorithm for high efficiency video coding
NASA Astrophysics Data System (ADS)
Zhou, Xin; Shi, Guangming; Zhou, Wei; Duan, Zhemin
2017-01-01
Intraprediction has been significantly improved in high efficiency video coding over H.264/AVC with quad-tree-based coding unit (CU) structure from size 64×64 to 8×8 and more prediction modes. However, these techniques cause a dramatic increase in computational complexity. An intracoding algorithm is proposed that consists of perceptual fast CU size decision algorithm and fast intraprediction mode decision algorithm. First, based on the visual saliency detection, an adaptive and fast CU size decision method is proposed to alleviate intraencoding complexity. Furthermore, a fast intraprediction mode decision algorithm with step halving rough mode decision method and early modes pruning algorithm is presented to selectively check the potential modes and effectively reduce the complexity of computation. Experimental results show that our proposed fast method reduces the computational complexity of the current HM to about 57% in encoding time with only 0.37% increases in BD rate. Meanwhile, the proposed fast algorithm has reasonable peak signal-to-noise ratio losses and nearly the same subjective perceptual quality.
Ferguson, Christopher J; San Miguel, Claudia; Hartley, Richard D
2009-12-01
To examine the multivariate nature of risk factors for youth violence including delinquent peer associations, exposure to domestic violence in the home, family conflict, neighborhood stress, antisocial personality traits, depression level, and exposure to television and video game violence. A population of 603 predominantly Hispanic children (ages 10-14 years) and their parents or guardians responded to multiple behavioral measures. Outcomes included aggression and rule-breaking behavior on the Child Behavior Checklist (CBCL), as well as violent and nonviolent criminal activity and bullying behavior. Delinquent peer influences, antisocial personality traits, depression, and parents/guardians who use psychological abuse in intimate relationships were consistent risk factors for youth violence and aggression. Neighborhood quality, parental use of domestic violence in intimate relationships, and exposure to violent television or video games were not predictive of youth violence and aggression. Childhood depression, delinquent peer association, and parental use of psychological abuse may be particularly fruitful avenues for future prevention or intervention efforts.
Video teleconsultation service: who is needed to do what, to get it implemented in daily care?
Visser, Jacqueline J W; Bloo, J K C; Grobbe, F A; Vollenbroek-Hutten, M M R
2010-05-01
In telemedicine, technology is used to deliver services. Because of this, it is expected that various actors other than those involved in traditional care are involved in and need to cooperate, to deliver these services. The aim of this study was to establish a clear understanding of these actors and their roles and interrelationships in the delivery of telemedicine. A video teleconsultation service is used as a study case. A business modeling approach as described in the Freeband Business Blueprint Method was used. The method brings together the four domains that make up a business model, that is, service, technology, organization, and finance, and covers the integration of these domains. The method uses several multidisciplinary workshops, addressing each of the four domains. Results of the four domains addressed showed that (1) the video teleconsultation service is a store and put-forward video teleconsult for healthcare providers. The service is accepted and has added value for the quality of care. However, the market is small; (2) the technology consists of a secured Internet Web-based application, standard personal computer, broadband Internet connection, and a digital camera; (3) a new role and probably entity, responsible for delivering the integrated service to the healthcare professionals, was identified; and finally (4) financial reimbursement for the service delivery is expected to be most successful when set up through healthcare insurance companies. Pricing needs to account for the fee of healthcare professionals as well as for technical aspects, education, and future innovation. Implementation of the video teleconsult service requires multidisciplinary cooperation and integration. Challenging aspects are the small market size and the slow implementation speed, among others. This supports the argument that accumulation of several telemedicine applications is necessary to make it financially feasible for at least some of the actors.
Duncan-Carnesciali, Joanne; Wallace, Barbara C; Odlum, Michelle
2018-06-01
Purpose The purpose of this study was to evaluate the perceptions that certified diabetes educators (CDEs), of diverse health professions, have of a culturally appropriate e-health intervention that used avatar-based technology. Methods Cross-sectional, survey-based design using quantitative and qualitative paradigms. A logic model framed the study, which centered on the broad and general concepts leading to study outcomes. In total, 198 CDEs participated in the evaluation. Participants were mostly female and represented an age range of 26 to 76 years. The profession representative of the sample was registered nurses. Study setting and data collection occurred at https://www.surveymonkey.com/r/AvatarVideoSurvey-for-Certified_Diabetes_Educators . Study instruments used were the Basic Demographics Survey (BD-13), Educational Material Use and Rating of Quality Scale (EMU-ROQ-9), Marlowe-Crowne Social Desirability Survey (MS-SOC-DES-CDE-13), Quality of Avatar Video Rating Scale (QAVRS-7), Recommend Avatar to Patients Scale (RAVTPS-3), Recommend Avatar Video to Health Professionals Scale (RAVTHP-3), and Avatar Video Applications Scale (AVAPP-1). Statistical analysis used included t tests, Pearson product moment correlations, backward stepwise regression, and content/thematic analysis. Results Age, ethnicity, Arab/Middle Eastern, Asian, and white/European descents were significant predictors of a high-quality rating of the video. Thematic and content analysis of the data revealed an overall positive perception of the video. Conclusions An e-health intervention grounded in evidence-based health behavior theories has potential to increase access to diabetes self-management education as evidenced in the ratings and perceptions of the video by CDEs.
NASA Astrophysics Data System (ADS)
Mantel, Claire; Korhonen, Jari; Pedersen, Jesper M.; Bech, Søren; Andersen, Jakob Dahl; Forchhammer, Søren
2015-01-01
This paper focuses on the influence of ambient light on the perceived quality of videos displayed on Liquid Crystal Display (LCD) with local backlight dimming. A subjective test assessing the quality of videos with two backlight dimming methods and three lighting conditions, i.e. no light, low light level (5 lux) and higher light level (60 lux) was organized to collect subjective data. Results show that participants prefer the method exploiting local dimming possibilities to the conventional full backlight but that this preference varies depending on the ambient light level. The clear preference for one method at the low light conditions decreases at the high ambient light, confirming that the ambient light significantly attenuates the perception of the leakage defect (light leaking through dark pixels). Results are also highly dependent on the content of the sequence, which can modulate the effect of the ambient light from having an important influence on the quality grades to no influence at all.
Falbe, Jennifer; Willett, Walter C; Rosner, Bernard; Gortmaker, Steve L; Sonneville, Kendrin R; Field, Alison E
2014-10-01
Youth spend more time with screens than any activity except sleeping. Screen time is a risk factor for obesity, possibly because of the influence of food and beverage advertising on diet. We sought to assess longitudinal relations of screen time [ie, television, electronic games, digital versatile discs (DVDs)/videos, and total screen time] with the 2-y changes in consumption of foods of low nutritional quality (FLNQ) that are commonly advertised on screens [ie, sugar-sweetened beverages, fast food, sweets, salty snacks, and the sum of these foods (total FLNQ)] and fruit and vegetables. With the use of 2004, 2006, and 2008 waves of the Growing Up Today Study II, which consisted of a cohort of 6002 female and 4917 male adolescents aged 9-16 y in 2004, we assessed screen time (change and baseline) in relation to the 2-y dietary changes. Regression models included 4604 girls and 3668 boys with complete screen time and diet data on ≥2 consecutive questionnaires. Each hour-per-day increase in television, electronic games, and DVDs/videos was associated with increased intake of total FLNQ (range: 0.10-0.28 servings/d; P < 0.05). Each hour-per-day increase in total screen time predicted increased intakes of sugar-sweetened beverages, fast food, sweets, and salty snacks (range: 0.02-0.06 servings/d; P < 0.001) and decreased intakes of fruit and vegetables (range: -0.05 to -0.02 servings/d; P < 0.05). Greater screen time at baseline (except electronic games in boys) was associated with subsequent increased intake of total FLNQ, and greater screen time at baseline (except DVDs/videos) was associated with decreased intake of fruit and vegetables (P < 0.05). Across sex and food groups and in sensitivity analyses, television was most consistently associated with dietary changes. Increases in screen time were associated with increased consumption of foods and beverages of low nutritional quality and decreased consumption of fruit and vegetables. Our results caution against excessive use of screen media, especially television, in youth. © 2014 American Society for Nutrition.
Multi-pass encoding of hyperspectral imagery with spectral quality control
NASA Astrophysics Data System (ADS)
Wasson, Steven; Walker, William
2015-05-01
Multi-pass encoding is a technique employed in the field of video compression that maximizes the quality of an encoded video sequence within the constraints of a specified bit rate. This paper presents research where multi-pass encoding is extended to the field of hyperspectral image compression. Unlike video, which is primarily intended to be viewed by a human observer, hyperspectral imagery is processed by computational algorithms that generally attempt to classify the pixel spectra within the imagery. As such, these algorithms are more sensitive to distortion in the spectral dimension of the image than they are to perceptual distortion in the spatial dimension. The compression algorithm developed for this research, which uses the Karhunen-Loeve transform for spectral decorrelation followed by a modified H.264/Advanced Video Coding (AVC) encoder, maintains a user-specified spectral quality level while maximizing the compression ratio throughout the encoding process. The compression performance may be considered near-lossless in certain scenarios. For qualitative purposes, this paper presents the performance of the compression algorithm for several Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Hyperion datasets using spectral angle as the spectral quality assessment function. Specifically, the compression performance is illustrated in the form of rate-distortion curves that plot spectral angle versus bits per pixel per band (bpppb).
The effect of texture granularity on texture synthesis quality
NASA Astrophysics Data System (ADS)
Golestaneh, S. Alireza; Subedar, Mahesh M.; Karam, Lina J.
2015-09-01
Natural and artificial textures occur frequently in images and in video sequences. Image/video coding systems based on texture synthesis can make use of a reliable texture synthesis quality assessment method in order to improve the compression performance in terms of perceived quality and bit-rate. Existing objective visual quality assessment methods do not perform satisfactorily when predicting the synthesized texture quality. In our previous work, we showed that texture regularity can be used as an attribute for estimating the quality of synthesized textures. In this paper, we study the effect of another texture attribute, namely texture granularity, on the quality of synthesized textures. For this purpose, subjective studies are conducted to assess the quality of synthesized textures with different levels (low, medium, high) of perceived texture granularity using different types of texture synthesis methods.
A Manual for Implementation of ABC Video Duplication Projects.
ERIC Educational Resources Information Center
Hill, Joseph, Ed.
The ABC (Appalachian BOCES Consortium) consists of 10 BOCES (Boards of Cooperative Educational Services) which serve the 14 southern counties of New York State designated as Appalachia. Each year since 1974, the ABC has participated in regional video duplication projects, which have yielded a total of nearly 4,000 video titles. The complexity of…
State Skill Standards: Digital Video & Broadcast Production
ERIC Educational Resources Information Center
Bullard, Susan; Tanner, Robin; Reedy, Brian; Grabavoi, Daphne; Ertman, James; Olson, Mark; Vaughan, Karen; Espinola, Ron
2007-01-01
The standards in this document are for digital video and broadcast production programs and are designed to clearly state what the student should know and be able to do upon completion of an advanced high-school program. Digital Video and Broadcast Production is a program that consists of the initial fundamentals and sequential courses that prepare…
Classification of a wetland area along the upper Mississippi River with aerial videography
Jennings, C.A.; Vohs, P.A.; Dewey, M.R.
1992-01-01
We evaluated the use of aerial videography for classifying wetland habitats along the upper Mississippi River and found the prompt availability of habitat feature maps to be the major advantage of the video imagery technique. We successfully produced feature maps from digitized video images that generally agreed with the known distribution and areal coverages of the major habitat types independently identified and quantified with photointerpretation techniques. However, video images were not sufficiently detailed to allow us to consistently discriminate among the classes of aquatic macrophytes present or to quantify their areal coverage. Our inability to consistently distinguish among emergent, floating, and submergent macrophytes from the feature maps may have been related to the structural complexity of the site, to our limited vegetation sampling, and to limitations in video imagery. We expect that careful site selection (i.e., the desired level of resolution is available from video imagery) and additional vegetation samples (e.g., along a transect) will allow improved assignment of spectral values to specific plant types and enhance plant classification from feature maps produced from video imagery.
Is basic personality related to violent and non-violent video game play and preferences?
Chory, Rebecca M; Goodboy, Alan K
2011-04-01
Based on the uses and gratifications perspective, personality was expected to relate to violent video game play frequency and game preferences. Participants completed measures of personality and frequency of violent video game play, and identified their most frequently played video games. Results indicate that individuals higher in openness but lower in agreeableness played violent video games more frequently. In addition, more open and extroverted but less agreeable and neurotic individuals generally preferred to play video games that are more violent. Results suggest personality may be more predictive of violent video game use than traditional media use, though the predictive personality dimensions may be consistent across media types.
A novel key-frame extraction approach for both video summary and video index.
Lei, Shaoshuai; Xie, Gang; Yan, Gaowei
2014-01-01
Existing key-frame extraction methods are basically video summary oriented; yet the index task of key-frames is ignored. This paper presents a novel key-frame extraction approach which can be available for both video summary and video index. First a dynamic distance separability algorithm is advanced to divide a shot into subshots based on semantic structure, and then appropriate key-frames are extracted in each subshot by SVD decomposition. Finally, three evaluation indicators are proposed to evaluate the performance of the new approach. Experimental results show that the proposed approach achieves good semantic structure for semantics-based video index and meanwhile produces video summary consistent with human perception.
Girgis, Afaf; Cockburn, Jill; Butow, Phyllis; Bowman, Deborah; Schofield, Penelope; Stojanovski, Elizabeth; D'Este, Catherine; Tattersall, Martin H N; Doran, Christopher; Turner, Jane
2009-12-01
To evaluate whether a consultation skills training (CST) program with oncologists and trainees would improve skills in detecting and responding to patient distress, thereby improving their patients' emotional functioning and reducing psychological distress. Randomized-controlled trial with 29 medical and radiation oncologists from Australia randomized to CST group (n=15) or usual-care group (n=14). The CST consisted of a 1.5-day face-to-face workshop incorporating presentation of principles, a DVD modelling ideal behaviour and role-play practice, and four 1.5h monthly video-conferences. At the CST conclusion, patients of participating doctors were recruited (n=192 in CST group, n=183 in usual-care group), completing telephone surveys at baseline, 1 week and 3 months to assess quality of life, anxiety, depression and unmet psychosocial needs. Despite high patient functioning at baseline, anxiety significantly improved at 1-week follow-up in the CST group, compared to the control group. There were no statistically significant differences in emotional functioning, depression or unmet supportive care need between the groups. Consistent trends for greater improvements were observed in intervention compared to control group patients, suggesting the CST program deserves wider evaluation. Video-conferencing after a short training course may be an effective strategy for delivering CST.
Behrends, Marianne; Stiller, Gerald; Dudzinska, Agnieszka; Schneidewind, Sabine
2016-01-01
To improve medical students' competences in physical examination videos clips were created, with and without an explaining commentary. The uncommented videos show the communication and interaction between physician and patient during a physical examination, the commented videos show the single steps of the physical examination supplemented with an off-screen commentary emphasizing important facts. To investigate whether uncommented and more authentic videos are more helpful to practice a physical examination than commented videos we interviewed 133 students via online surveys. 72% of the students used the uncommented videos for practicing with others, compared to 55% using the commented videos. 37% of the students think that practical skills can be learned better with the uncommented videos. In general, 97% state that the videos helped them to improve their skills. Our findings indicate that the cinematic form of an educational video has an effect on learning behavior, learning success and didactic quality.
ERIC Educational Resources Information Center
Batty, Aaron Olaf
2015-01-01
The rise in the affordability of quality video production equipment has resulted in increased interest in video-mediated tests of foreign language listening comprehension. Although research on such tests has continued fairly steadily since the early 1980s, studies have relied on analyses of raw scores, despite the growing prevalence of item…
ERIC Educational Resources Information Center
Tykwinski, Joseph R.; Poulin, Russell C.
North Dakota is one of the first states to create a statewide system--the Interactive Video Network (IVN)--that allows multiple video conferencing between two or more sites. In 1990-91, IVN connected 10 campuses and the State Capitol. IVN's purpose is to deliver quality postsecondary programs to students who would not otherwise have access to…
ERIC Educational Resources Information Center
Ljubojevic, Milos; Vaskovic, Vojkan; Stankovic, Srecko; Vaskovic, Jelena
2014-01-01
The main objective of this research is to investigate efficiency of use of supplementary video content in multimedia teaching. Integrating video clips in multimedia lecture presentations may increase students' perception of important information and motivation for learning. Because of that, students can better understand and remember key points of…
ERIC Educational Resources Information Center
Gardner, Stephanie; Wolfe, Pamela
2013-01-01
Identifying methods to increase the independent functioning of individuals with autism spectrum disorders (ASD) is vital in enhancing their quality of life; teaching students with ASD daily living skills can foster independent functioning. This review examines interventions that implement video modeling and/or prompting to teach individuals with…
Record Desktop Activity as Streaming Videos for Asynchronous, Video-Based Collaborative Learning.
ERIC Educational Resources Information Center
Chang, Chih-Kai
As Web-based courses using videos have become popular in recent years, the issue of managing audiovisual aids has become noteworthy. The contents of audiovisual aids may include a lecture, an interview, a featurette, an experiment, etc. The audiovisual aids of Web-based courses are transformed into the streaming format that can make the quality of…
Innovative Video Diagnostic Equipment for Material Science
NASA Technical Reports Server (NTRS)
Capuano, G.; Titomanlio, D.; Soellner, W.; Seidel, A.
2012-01-01
Materials science experiments under microgravity increasingly rely on advanced optical systems to determine the physical properties of the samples under investigation. This includes video systems with high spatial and temporal resolution. The acquisition, handling, storage and transmission to ground of the resulting video data are very challenging. Since the available downlink data rate is limited, the capability to compress the video data significantly without compromising the data quality is essential. We report on the development of a Digital Video System (DVS) for EML (Electro Magnetic Levitator) which provides real-time video acquisition, high compression using advanced Wavelet algorithms, storage and transmission of a continuous flow of video with different characteristics in terms of image dimensions and frame rates. The DVS is able to operate with the latest generation of high-performance cameras acquiring high resolution video images up to 4Mpixels@60 fps or high frame rate video images up to about 1000 fps@512x512pixels.
Video Image Stabilization and Registration (VISAR) Software
NASA Technical Reports Server (NTRS)
1999-01-01
Two scientists at NASA's Marshall Space Flight Center,atmospheric scientist Paul Meyer and solar physicist Dr. David Hathaway, developed promising new software, called Video Image Stabilization and Registration (VISAR). VISAR may help law enforcement agencies catch criminals by improving the quality of video recorded at crime scenes. In this photograph, the single frame at left, taken at night, was brightened in order to enhance details and reduce noise or snow. To further overcome the video defects in one frame, Law enforcement officials can use VISAR software to add information from multiple frames to reveal a person. Images from less than a second of videotape were added together to create the clarified image at right. VISAR stabilizes camera motion in the horizontal and vertical as well as rotation and zoom effects producing clearer images of moving objects, smoothes jagged edges, enhances still images, and reduces video noise or snow. VISAR could also have applications in medical and meteorological imaging. It could steady images of ultrasounds, which are infamous for their grainy, blurred quality. The software can be used for defense application by improving recornaissance video imagery made by military vehicles, aircraft, and ships traveling in harsh, rugged environments.
IVTS-CEV (Interactive Video Tape System-Combat Engineer Vehicle) Gunnery Trainer.
1981-07-01
video game technology developed for and marketed in consumer video games. The IVTS/CEV is a conceptual/breadboard-level classroom interactive training system designed to train Combat Engineer Vehicle (CEV) gunners in target acquisition and engagement with the main gun. The concept demonstration consists of two units: a gunner station and a display module. The gunner station has optics and gun controls replicating those of the CEV gunner station. The display module contains a standard large-screen color video monitor and a video tape player. The gunner’s sight
Longitudinal effects of violent video games on aggression in Japan and the United States.
Anderson, Craig A; Sakamoto, Akira; Gentile, Douglas A; Ihori, Nobuko; Shibuya, Akiko; Yukawa, Shintaro; Naito, Mayumi; Kobayashi, Kumiko
2008-11-01
Youth worldwide play violent video games many hours per week. Previous research suggests that such exposure can increase physical aggression. We tested whether high exposure to violent video games increases physical aggression over time in both high- (United States) and low- (Japan) violence cultures. We hypothesized that the amount of exposure to violent video games early in a school year would predict changes in physical aggressiveness assessed later in the school year, even after statistically controlling for gender and previous physical aggressiveness. In 3 independent samples, participants' video game habits and physically aggressive behavior tendencies were assessed at 2 points in time, separated by 3 to 6 months. One sample consisted of 181 Japanese junior high students ranging in age from 12 to 15 years. A second Japanese sample consisted of 1050 students ranging in age from 13 to 18 years. The third sample consisted of 364 United States 3rd-, 4th-, and 5th-graders ranging in age from 9 to 12 years. RESULTS. Habitual violent video game play early in the school year predicted later aggression, even after controlling for gender and previous aggressiveness in each sample. Those who played a lot of violent video games became relatively more physically aggressive. Multisample structure equation modeling revealed that this longitudinal effect was of a similar magnitude in the United States and Japan for similar-aged youth and was smaller (but still significant) in the sample that included older youth. These longitudinal results confirm earlier experimental and cross-sectional studies that had suggested that playing violent video games is a significant risk factor for later physically aggressive behavior and that this violent video game effect on youth generalizes across very different cultures. As a whole, the research strongly suggests reducing the exposure of youth to this risk factor.
NASA Astrophysics Data System (ADS)
Nagaoka, Chika; Komori, Masashi
Body movement synchrony (i. e. rhythmic synchronization between the body movements of interacting partners) has been described by subjective impressions of skilled counselors and has been considered to reflect the depth of the client-counselor relationship. This study analyzed temporal changes in body movement synchrony through a video analysis of client-counselor dialogues in counseling sessions. Four 50-minute psychotherapeutic counseling sessions were analyzed, including two negatively evaluated sessions (low evaluation groups) and two positively evaluated sessions (high evaluation groups). In addition, two 50-minute ordinary advice sessions between two high school teachers and the clients in the high rating group were analyzed. All sessions represent role-playing. The intensity of the participants' body movement was measured using a video-based system. Temporal change of body movement synchrony was analyzed using moving correlations of the intensity between the two time series. The results revealed (1) A consistent temporal pattern among the four counseling cases, though the moving correlation coefficients were higher for the high evaluation group than the low evaluation group and (2) Different temporal patterns for the counseling and advice sessions even when the clients were the same. These results were discussed from the perspective of the quality of client-counselor relationship.
Real-time bicycle detection at signalized intersections using thermal imaging technology
NASA Astrophysics Data System (ADS)
Collaert, Robin
2013-02-01
More and more governments and authorities around the world are promoting the use of bicycles in cities, as this is healthy for the bicyclist and improves the quality of life in general. Safety and efficiency of bicyclists has become a major focus. To achieve this, there is a need for a smarter approach towards the control of signalized intersections. Various traditional detection technologies, such as video, microwave radar and electromagnetic loops, can be used to detect vehicles at signalized intersections, but none of these can consistently separate bikes from other traffic, day and night and in various weather conditions. As bikes should get a higher priority and also require longer green time to safely cross the signalized intersection, traffic managers are looking for alternative detection systems that can make the distinction between bicycles and other vehicles near the stop bar. In this paper, the drawbacks of a video-based approach are presented, next to the benefits of a thermal-video-based approach for vehicle presence detection with separation of bicycles. Also, the specific technical challenges are highlighted in developing a system that combines thermal image capturing, image processing and output triggering to the traffic light controller in near real-time and in a single housing.
Experienced quality factors: qualitative evaluation approach to audiovisual quality
NASA Astrophysics Data System (ADS)
Jumisko-Pyykkö, Satu; Häkkinen, Jukka; Nyman, Göte
2007-02-01
Subjective evaluation is used to identify impairment factors of multimedia quality. The final quality is often formulated via quantitative experiments, but this approach has its constraints, as subject's quality interpretations, experiences and quality evaluation criteria are disregarded. To identify these quality evaluation factors, this study examined qualitatively the criteria participants used to evaluate audiovisual video quality. A semi-structured interview was conducted with 60 participants after a subjective audiovisual quality evaluation experiment. The assessment compared several, relatively low audio-video bitrate ratios with five different television contents on mobile device. In the analysis, methodological triangulation (grounded theory, Bayesian networks and correspondence analysis) was applied to approach the qualitative quality. The results showed that the most important evaluation criteria were the factors of visual quality, contents, factors of audio quality, usefulness - followability and audiovisual interaction. Several relations between the quality factors and the similarities between the contents were identified. As a research methodological recommendation, the focus on content and usage related factors need to be further examined to improve the quality evaluation experiments.
Video Game Use in the Treatment of Amblyopia: Weighing the Risks of Addiction
Xu, Chaoying S.; Chen, Jessica S.; Adelman, Ron A.
2015-01-01
Video games have surged in popularity due to their entertainment factor and, with recent innovation, their use in health care. This review explores the dual facets of video games in treating vision impairment in amblyopia as well as their potential for overuse and addiction. Specifically, this review examines video game addiction from a biopsychosocial perspective and relates the addictive qualities of video games with their use as a therapeutic treatment for amblyopia. Current literature supports both the identification of video game addiction as a disease, as well as the therapeutic potential of video games in clinical trials. We show the need for clinicians to be aware of the dangers associated with video game overuse and the need for future studies to examine the risks associated with their health care benefits. PMID:26339215
Lin, Yu-You; Chiang, Wen-Chu; Hsieh, Ming-Ju; Sun, Jen-Tang; Chang, Yi-Chung; Ma, Matthew Huei-Ming
2018-02-01
This study aimed to conduct a systematic review and meta-analysis comparing the effect of video-assistance and audio-assistance on quality of dispatcher-instructed cardiopulmonary resuscitation (DI-CPR) for bystanders. Five databases were searched, including PubMed, Cochrane library, Embase, Scopus and NIH clinical trial, to find randomized control trials published before June 2017. Qualitative analysis and meta-analysis were undertaken to examine the difference between the quality of video-instructed and audio-instructed dispatcher-instructed bystander CPR. The database search yielded 929 records, resulting in the inclusion of 9 relevant articles in this study. Of these, 6 were included in the meta-analysis. Initiation of chest compressions was slower in the video-instructed group than in the audio-instructed group (median delay 31.5 s; 95% CI: 10.94-52.09). The difference in the number of chest compressions per minute between the groups was 19.9 (95% CI: 10.50-29.38) with significantly faster compressions in the video-instructed group than in the audio-instructed group (104.8 vs. 80.6). The odds ratio (OR) for correct hand positioning was 0.8 (95% CI: 0.53-1.30) when comparing the audio-instructed and video-instructed groups. The differences in chest compression depth (mm) and time to first ventilation (seconds) between the video-instructed group and audio-instructed group were 1.6 mm (95% CI: -8.75, 5.55) and 7.5 s (95% CI: -56.84, 71.80), respectively. Video-instructed DI-CPR significantly improved the chest compression rate compared to the audio-instructed method, and a trend for correctness of hand position was also observed. However, this method caused a delay in the commencement of bystander-initiated CPR in the simulation setting. Copyright © 2017 Elsevier B.V. All rights reserved.
YouTube provides poor information regarding anterior cruciate ligament injury and reconstruction.
Cassidy, J T; Fitzgerald, E; Cassidy, E S; Cleary, M; Byrne, D P; Devitt, B M; Baker, J F
2018-03-01
YouTube is a global medium used predominantly by young adults (aged 18-49 years). This study examined the quality of YouTube information regarding ACL injury and reconstruction. YouTube was searched on the 13th of June 2015 for "ACL" and "anterior cruciate ligament" with/without associated terms of "injury", "reconstruction", and "surgery". Videos were evaluated by two independent reviewers [EF (Reviewer 1), (Reviewer 2)] using two recognized information scoring systems (Modified DISCERN (MD) 0-5 and JAMA Benchmark 0-4) and an adaptation of a score designed for written ACL information [ACL Specific Score (ASS) 0-25]. The ASS categorized scores as very good (21-25), good (16-20), moderate (11-15), poor (6-10), and very poor (0-5). Number of views/likes/dislikes, animation, and continent of origin and source (e.g., corporate/educational) were recorded. Correlation of video characteristics with number of views was examined using the analysis of variance (ANOVA) model. Agreement between reviewers was assessed by Interclass Correlation Co-efficient (ICC). Following a filtering process of the 964,770 identified videos, 39 videos were retained. The mean MD score was 2.3 (standard deviation (SD) ±0.9) for Reviewer 1 and 2.2 (SD ±0.9) for Reviewer 2 (ICC = 0.7). The mean JAMA score was 2.5(SD ±0.7) for Reviewer 1 and 2.3 (SD ±0.7) for Reviewer 2 (ICC = 0.8). The mean ASS was 6.3 (SD ±3.5) for Reviewer 1 and 4.6 (SD ±2.9) for Reviewer 2 (ICC = 0.9). Five videos achieved moderate score (13%), while 15 (38%) and 19 (49%) scored as poor and very poor, respectively. There was no correlation between number of views and video quality/video source for any scoring system. The majority of videos viewed on YouTube regarding ACL injury and treatment are of low quality.
2012-01-01
Background Few educational resources have been developed to inform patients’ renal replacement therapy (RRT) selection decisions. Patients progressing toward end stage renal disease (ESRD) must decide among multiple treatment options with varying characteristics. Complex information about treatments must be adequately conveyed to patients with different educational backgrounds and informational needs. Decisions about treatment options also require family input, as families often participate in patients’ treatment and support patients’ decisions. We describe the development, design, and preliminary evaluation of an informational, evidence-based, and patient-and family-centered decision aid for patients with ESRD and varying levels of health literacy, health numeracy, and cognitive function. Methods We designed a decision aid comprising a complementary video and informational handbook. We based our development process on data previously obtained from qualitative focus groups and systematic literature reviews. We simultaneously developed the video and handbook in “stages.” For the video, stages included (1) directed interviews with culturally appropriate patients and families and preliminary script development, (2) video production, and (3) screening the video with patients and their families. For the handbook, stages comprised (1) preliminary content design, (2) a mixed-methods pilot study among diverse patients to assess comprehension of handbook material, and (3) screening the handbook with patients and their families. Results The video and handbook both addressed potential benefits and trade-offs of treatment selections. The 50-minute video consisted of demographically diverse patients and their families describing their positive and negative experiences with selecting a treatment option. The video also incorporated health professionals’ testimonials regarding various considerations that might influence patients’ and families’ treatment selections. The handbook was comprised of written words, pictures of patients and health care providers, and diagrams describing the findings and quality of scientific studies comparing treatments. The handbook text was written at a 4th to 6th grade reading level. Pilot study results demonstrated that a majority of patients could understand information presented in the handbook. Patient and families screening the nearly completed video and handbook reviewed the materials favorably. Conclusions This rigorously designed decision aid may help patients and families make informed decisions about their treatment options for RRT that are well aligned with their values. PMID:23198793
Fast image interpolation for motion estimation using graphics hardware
NASA Astrophysics Data System (ADS)
Kelly, Francis; Kokaram, Anil
2004-05-01
Motion estimation and compensation is the key to high quality video coding. Block matching motion estimation is used in most video codecs, including MPEG-2, MPEG-4, H.263 and H.26L. Motion estimation is also a key component in the digital restoration of archived video and for post-production and special effects in the movie industry. Sub-pixel accurate motion vectors can improve the quality of the vector field and lead to more efficient video coding. However sub-pixel accuracy requires interpolation of the image data. Image interpolation is a key requirement of many image processing algorithms. Often interpolation can be a bottleneck in these applications, especially in motion estimation due to the large number pixels involved. In this paper we propose using commodity computer graphics hardware for fast image interpolation. We use the full search block matching algorithm to illustrate the problems and limitations of using graphics hardware in this way.
SU-C-209-06: Improving X-Ray Imaging with Computer Vision and Augmented Reality
DOE Office of Scientific and Technical Information (OSTI.GOV)
MacDougall, R.D.; Scherrer, B; Don, S
Purpose: To determine the feasibility of using a computer vision algorithm and augmented reality interface to reduce repeat rates and improve consistency of image quality and patient exposure in general radiography. Methods: A prototype device, designed for use with commercially available hardware (Microsoft Kinect 2.0) capable of depth sensing and high resolution/frame rate video, was mounted to the x-ray tube housing as part of a Philips DigitalDiagnost digital radiography room. Depth data and video was streamed to a Windows 10 PC. Proprietary software created an augmented reality interface where overlays displayed selectable information projected over real-time video of the patient.more » The information displayed prior to and during x-ray acquisition included: recognition and position of ordered body part, position of image receptor, thickness of anatomy, location of AEC cells, collimated x-ray field, degree of patient motion and suggested x-ray technique. Pre-clinical data was collected in a volunteer study to validate patient thickness measurements and x-ray images were not acquired. Results: Proprietary software correctly identified ordered body part, measured patient motion, and calculated thickness of anatomy. Pre-clinical data demonstrated accuracy and precision of body part thickness measurement when compared with other methods (e.g. laser measurement tool). Thickness measurements provided the basis for developing a database of thickness-based technique charts that can be automatically displayed to the technologist. Conclusion: The utilization of computer vision and commercial hardware to create an augmented reality view of the patient and imaging equipment has the potential to drastically improve the quality and safety of x-ray imaging by reducing repeats and optimizing technique based on patient thickness. Society of Pediatric Radiology Pilot Grant; Washington University Bear Cub Fund.« less
Subjective evaluation of H.265/HEVC based dynamic adaptive video streaming over HTTP (HEVC-DASH)
NASA Astrophysics Data System (ADS)
Irondi, Iheanyi; Wang, Qi; Grecos, Christos
2015-02-01
The Dynamic Adaptive Streaming over HTTP (DASH) standard is becoming increasingly popular for real-time adaptive HTTP streaming of internet video in response to unstable network conditions. Integration of DASH streaming techniques with the new H.265/HEVC video coding standard is a promising area of research. The performance of HEVC-DASH systems has been previously evaluated by a few researchers using objective metrics, however subjective evaluation would provide a better measure of the user's Quality of Experience (QoE) and overall performance of the system. This paper presents a subjective evaluation of an HEVC-DASH system implemented in a hardware testbed. Previous studies in this area have focused on using the current H.264/AVC (Advanced Video Coding) or H.264/SVC (Scalable Video Coding) codecs and moreover, there has been no established standard test procedure for the subjective evaluation of DASH adaptive streaming. In this paper, we define a test plan for HEVC-DASH with a carefully justified data set employing longer video sequences that would be sufficient to demonstrate the bitrate switching operations in response to various network condition patterns. We evaluate the end user's real-time QoE online by investigating the perceived impact of delay, different packet loss rates, fluctuating bandwidth, and the perceived quality of using different DASH video stream segment sizes on a video streaming session using different video sequences. The Mean Opinion Score (MOS) results give an insight into the performance of the system and expectation of the users. The results from this study show the impact of different network impairments and different video segments on users' QoE and further analysis and study may help in optimizing system performance.
YouTube and the single-rod contraceptive implant: a content analysis.
Paul, Jennifer; Boraas, Christy M; Duvet, Mildred; Chang, Judy C
2017-07-01
Since the internet has become an important source of contraceptive information with YouTube.com as the second most visited site, we analysed contraceptive implant YouTube videos for content and clinical accuracy. Using the terms 'contraceptive implant', 'Nexplanon' and 'Implanon', the top 20 results on YouTube by relevance and view count were identified. After excluding duplicates, single-rod implant videos in English were included. Videos were classified as providing a professional or patient perspective. Views, duration and comments were noted. Videos were rated for reliability, global quality scale and whether they were positive or negative about the implant. Inter-rater agreement was measured. A total of 120 videos were retrieved; 52 were eligible for review. Less than 23% were professional videos; the majority reported patient experience (46% testimonials, 27% real-time procedure videos, 4% other). Patient videos had been posted a significantly longer duration of time than professional videos (364 vs 188 days, p =0.02), were less reliable ( p ≤0.0001) and were of lower global quality ( p <0.0001). Some 61% of implant testimonial videos were rated as 'positive experiences' and inter-rater agreement was very good (κ=0.81). All testimonials mentioned side effects, commonly irregular bleeding and discomfort with insertion. A minority (26%) reported misinformation. This study found that most of the information on YouTube pertaining to contraceptive implants is accurate, is presented from the patient's perspective, and promotes the method's use. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Speckle reduction in echocardiography by temporal compounding and anisotropic diffusion filtering
NASA Astrophysics Data System (ADS)
Giraldo-Guzmán, Jader; Porto-Solano, Oscar; Cadena-Bonfanti, Alberto; Contreras-Ortiz, Sonia H.
2015-01-01
Echocardiography is a medical imaging technique based on ultrasound signals that is used to evaluate heart anatomy and physiology. Echocardiographic images are affected by speckle, a type of multiplicative noise that obscures details of the structures, and reduces the overall image quality. This paper shows an approach to enhance echocardiography using two processing techniques: temporal compounding and anisotropic diffusion filtering. We used twenty echocardiographic videos that include one or three cardiac cycles to test the algorithms. Two images from each cycle were aligned in space and averaged to obtain the compound images. These images were then processed using anisotropic diffusion filters to further improve their quality. Resultant images were evaluated using quality metrics and visual assessment by two medical doctors. The average total improvement on signal-to-noise ratio was up to 100.29% for videos with three cycles, and up to 32.57% for videos with one cycle.
Ravì, Daniele; Szczotka, Agnieszka Barbara; Shakir, Dzhoshkun Ismail; Pereira, Stephen P; Vercauteren, Tom
2018-06-01
Probe-based confocal laser endomicroscopy (pCLE) is a recent imaging modality that allows performing in vivo optical biopsies. The design of pCLE hardware, and its reliance on an optical fibre bundle, fundamentally limits the image quality with a few tens of thousands fibres, each acting as the equivalent of a single-pixel detector, assembled into a single fibre bundle. Video registration techniques can be used to estimate high-resolution (HR) images by exploiting the temporal information contained in a sequence of low-resolution (LR) images. However, the alignment of LR frames, required for the fusion, is computationally demanding and prone to artefacts. In this work, we propose a novel synthetic data generation approach to train exemplar-based Deep Neural Networks (DNNs). HR pCLE images with enhanced quality are recovered by the models trained on pairs of estimated HR images (generated by the video registration algorithm) and realistic synthetic LR images. Performance of three different state-of-the-art DNNs techniques were analysed on a Smart Atlas database of 8806 images from 238 pCLE video sequences. The results were validated through an extensive image quality assessment that takes into account different quality scores, including a Mean Opinion Score (MOS). Results indicate that the proposed solution produces an effective improvement in the quality of the obtained reconstructed image. The proposed training strategy and associated DNNs allows us to perform convincing super-resolution of pCLE images.
A model for a PC-based, universal-format, multimedia digitization system: moving beyond the scanner.
McEachen, James C; Cusack, Thomas J; McEachen, John C
2003-08-01
Digitizing images for use in case presentations based on hardcopy films, slides, photographs, negatives, books, and videos can present a challenging task. Scanners and digital cameras have become standard tools of the trade. Unfortunately, use of these devices to digitize multiple images in many different media formats can be a time-consuming and in some cases unachievable process. The authors' goal was to create a PC-based solution for digitizing multiple media formats in a timely fashion while maintaining adequate image presentation quality. The authors' PC-based solution makes use of off-the-shelf hardware applications to include a digital document camera (DDC), VHS video player, and video-editing kit. With the assistance of five staff radiologists, the authors examined the quality of multiple image types digitized with this equipment. The authors also quantified the speed of digitization of various types of media using the DDC and video-editing kit. With regard to image quality, the five staff radiologists rated the digitized angiography, CT, and MR images as adequate to excellent for use in teaching files and case presentations. With regard to digitized plain films, the average rating was adequate. As for performance, the authors recognized a 68% improvement in the time required to digitize hardcopy films using the DDC instead of a professional quality scanner. The PC-based solution provides a means for digitizing multiple images from many different types of media in a timely fashion while maintaining adequate image presentation quality.
Designing professional development to increase local capacity to sustain reform
NASA Astrophysics Data System (ADS)
Fogleman, Jay A.
There is a rich tradition of using curriculum materials to foster reform and innovation in science education. A key issue in any materials development effort is how to engender high-quality enactments of new materials, and how to sustain and scale up high-quality use so that the materials have a lasting and meaningful impact on the education of students. Many have argued that professional development (PD) is a key to the long-term success of systemic reform initiatives and there is a dire need for resources that help districts sustain PD opportunities that support teachers using innovations beyond their initial implementation. This dissertation consists of three manuscripts that look at the process of understanding teachers' use of reform-rich materials and supporting teacher professional development in the context of efforts by districts and innovators to implement and sustain their use in middle school science classrooms. The first manuscript looks specifically at the practices of teachers using learning-goals driven curriculum materials in an effort to model the effects of these practices on student achievement. Teacher surveys and video recording were used to relate teachers' characteristics and practices to student achievement using a multi-level approach. The second manuscript uses video recordings to critically examine a professional development workshop enacted by curriculum developers to identify knowledge and strategies that might be adapted for use locally to sustain PD offerings. The third manuscript presents two cases that describe how a professional development workcircle consisting of university researchers, district personnel, and lead teachers was able to sustain district-led professional development around reform-rich curriculum materials. Findings from the three studies are considered in light of factors necessary to sustain and scale the use of educational innovations and a model for supporting local PD is suggested.
YouTube as a patient-information source for root canal treatment.
Nason, K; Donnelly, A; Duncan, H F
2016-12-01
To assess the content and completeness of Youtube ™ as an information source for patients undergoing root canal treatment procedures. YouTube ™ (https://www.youtube.com/) was searched for information using three relevant treatment search terms ('endodontics', 'root canal' and 'root canal treatment'). After exclusions (language, no audio, >15 min, duplicates), 20 videos per search term were selected. General video assessment included duration, ownership, views, age, likes/dislikes, target audience and video/audio quality, whilst content was analysed under six categories ('aetiology', 'anatomy', 'symptoms', 'procedure', 'postoperative course' and 'prognosis'). Content was scored for completeness level and statistically analysed using anova and post hoc Tukey's test (P < 0.05). To obtain 60 acceptable videos, 124 were assessed. Depending on the search term employed, the video content and ownership differed markedly. There was wide variation in both the number of video views and 'likes/dislikes'. The average video age was 788 days. In total, 46% of videos were 'posted' by a dentist/specialist source; however, this was search term specific rising to 70% of uploads for the search 'endodontic', whilst laypersons contributed 18% of uploads for the search 'root canal treatment'. Every video lacked content in the designated six categories, although 'procedure' details were covered more frequently and in better detail than other categories. Videos posted by dental professional (P = 0.046) and commercial sources (P = 0.009) were significantly more complete than videos posted by laypeople. YouTube ™ videos for endodontic search terms varied significantly by source and content and were generally incomplete. The danger of patient reliance on YouTube ™ is highlighted, as is the need for endodontic professionals to play an active role in directing patients towards alternative high-quality information sources. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.
Muhammed, Louwai; Adcock, Jane E; Sen, Arjune
2014-08-01
Medical students are increasingly turning to the website YouTube as a learning resource. This study set out to determine whether the videos on YouTube accurately depict the type of seizures that a medical student may search for. Two consultant epileptologists independently assessed the top YouTube videos returned following searches for eight terms relating to different categories of seizures. The videos were rated for their technical quality, concordance of diagnosis with an epileptologist-assigned diagnosis, and efficacy as a learning tool for medical education. Of the 200 videos assessed, 106 (63%) met the inclusion criteria for further analysis. Technical quality was generally good and only interfered with the diagnostic process in 8.5% of the videos. Of the included videos, 40.6-46.2% were judged to depict the purported diagnosis with moderate agreement between raters (75% agreement, κ=0.50). Of the videos returned after searching "tonic-clonic seizure", 28.6-35.7% were judged to show nonepileptic seizures with almost perfect interrater agreement (92.9% agreement, κ=0.84). Of the videos returned following the search "pseudoseizure", 77.8-88.9% of videos were judged to show nonepileptic seizures with substantial agreement (88.9% agreement, κ=0.61). Across all search terms, 19.8-33% of videos were judged as potentially useful as a learning resource, with fair agreement between raters (75.5% agreement, κ=0.38). These findings suggest that the majority of videos on YouTube claiming to show specific seizure subtypes are inaccurate, and YouTube should not be recommended as a learning tool for students. However, a small group of videos provides excellent demonstrations of tonic-clonic and nonepileptic seizures, which could be used by an expert teacher to demonstrate the difference between epileptic and nonepileptic seizures. Copyright © 2014 Elsevier Inc. All rights reserved.
Analysis of the IJCNN 2011 UTL Challenge
2012-01-13
large datasets from various application domains: handwriting recognition, image recognition, video processing, text processing, and ecology. The goal...http //clopinet.com/ul). We made available large datasets from various application domains handwriting recognition, image recognition, video...evaluation sets consist of 4096 examples each. Dataset Domain Features Sparsity Devel. Transf. AVICENNA Handwriting 120 0% 150205 50000 HARRY Video 5000 98.1
Li, Jia; Xia, Changqun; Chen, Xiaowu
2017-10-12
Image-based salient object detection (SOD) has been extensively studied in past decades. However, video-based SOD is much less explored due to the lack of large-scale video datasets within which salient objects are unambiguously defined and annotated. Toward this end, this paper proposes a video-based SOD dataset that consists of 200 videos. In constructing the dataset, we manually annotate all objects and regions over 7,650 uniformly sampled keyframes and collect the eye-tracking data of 23 subjects who free-view all videos. From the user data, we find that salient objects in a video can be defined as objects that consistently pop-out throughout the video, and objects with such attributes can be unambiguously annotated by combining manually annotated object/region masks with eye-tracking data of multiple subjects. To the best of our knowledge, it is currently the largest dataset for videobased salient object detection. Based on this dataset, this paper proposes an unsupervised baseline approach for video-based SOD by using saliencyguided stacked autoencoders. In the proposed approach, multiple spatiotemporal saliency cues are first extracted at the pixel, superpixel and object levels. With these saliency cues, stacked autoencoders are constructed in an unsupervised manner that automatically infers a saliency score for each pixel by progressively encoding the high-dimensional saliency cues gathered from the pixel and its spatiotemporal neighbors. In experiments, the proposed unsupervised approach is compared with 31 state-of-the-art models on the proposed dataset and outperforms 30 of them, including 19 imagebased classic (unsupervised or non-deep learning) models, six image-based deep learning models, and five video-based unsupervised models. Moreover, benchmarking results show that the proposed dataset is very challenging and has the potential to boost the development of video-based SOD.
NASA Astrophysics Data System (ADS)
Pandremmenou, K.; Tziortziotis, N.; Paluri, S.; Zhang, W.; Blekas, K.; Kondi, L. P.; Kumar, S.
2015-03-01
We propose the use of the Least Absolute Shrinkage and Selection Operator (LASSO) regression method in order to predict the Cumulative Mean Squared Error (CMSE), incurred by the loss of individual slices in video transmission. We extract a number of quality-relevant features from the H.264/AVC video sequences, which are given as input to the LASSO. This method has the benefit of not only keeping a subset of the features that have the strongest effects towards video quality, but also produces accurate CMSE predictions. Particularly, we study the LASSO regression through two different architectures; the Global LASSO (G.LASSO) and Local LASSO (L.LASSO). In G.LASSO, a single regression model is trained for all slice types together, while in L.LASSO, motivated by the fact that the values for some features are closely dependent on the considered slice type, each slice type has its own regression model, in an e ort to improve LASSO's prediction capability. Based on the predicted CMSE values, we group the video slices into four priority classes. Additionally, we consider a video transmission scenario over a noisy channel, where Unequal Error Protection (UEP) is applied to all prioritized slices. The provided results demonstrate the efficiency of LASSO in estimating CMSE with high accuracy, using only a few features. les that typically contain high-entropy data, producing a footprint that is far less conspicuous than existing methods. The system uses a local web server to provide a le system, user interface and applications through an web architecture.
Improving human object recognition performance using video enhancement techniques
NASA Astrophysics Data System (ADS)
Whitman, Lucy S.; Lewis, Colin; Oakley, John P.
2004-12-01
Atmospheric scattering causes significant degradation in the quality of video images, particularly when imaging over long distances. The principle problem is the reduction in contrast due to scattered light. It is known that when the scattering particles are not too large compared with the imaging wavelength (i.e. Mie scattering) then high spatial resolution information may be contained within a low-contrast image. Unfortunately this information is not easily perceived by a human observer, particularly when using a standard video monitor. A secondary problem is the difficulty of achieving a sharp focus since automatic focus techniques tend to fail in such conditions. Recently several commercial colour video processing systems have become available. These systems use various techniques to improve image quality in low contrast conditions whilst retaining colour content. These systems produce improvements in subjective image quality in some situations, particularly in conditions of haze and light fog. There is also some evidence that video enhancement leads to improved ATR performance when used as a pre-processing stage. Psychological literature indicates that low contrast levels generally lead to a reduction in the performance of human observers in carrying out simple visual tasks. The aim of this paper is to present the results of an empirical study on object recognition in adverse viewing conditions. The chosen visual task was vehicle number plate recognition at long ranges (500 m and beyond). Two different commercial video enhancement systems are evaluated using the same protocol. The results show an increase in effective range with some differences between the different enhancement systems.
Implementation and Analysis of Real-Time Streaming Protocols
Santos-González, Iván; Rivero-García, Alexandra; Molina-Gil, Jezabel; Caballero-Gil, Pino
2017-01-01
Communication media have become the primary way of interaction thanks to the discovery and innovation of many new technologies. One of the most widely used communication systems today is video streaming, which is constantly evolving. Such communications are a good alternative to face-to-face meetings, and are therefore very useful for coping with many problems caused by distance. However, they suffer from different issues such as bandwidth limitation, network congestion, energy efficiency, cost, reliability and connectivity. Hence, the quality of service and the quality of experience are considered the two most important issues for this type of communication. This work presents a complete comparative study of two of the most used protocols of video streaming, Real Time Streaming Protocol (RTSP) and the Web Real-Time Communication (WebRTC). In addition, this paper proposes two new mobile applications that implement those protocols in Android whose objective is to know how they are influenced by the aspects that most affect the streaming quality of service, which are the connection establishment time and the stream reception time. The new video streaming applications are also compared with the most popular video streaming applications for Android, and the experimental results of the analysis show that the developed WebRTC implementation improves the performance of the most popular video streaming applications with respect to the stream packet delay. PMID:28417949
Cañon, Daniel E; Lopez, Diego M; Blobel, Bernd
2014-01-01
Moderation of content in online Health Social Networks (HSN) is critical because information is not only published and produced by experts or health professionals, but also by users of that information. The objective of this paper is to propose a semi-automatic moderation Web Service for assessing the quality (trustworthiness) of health-related videos published on the YouTube social network. The service is relevant for moderators or community managers, who get enabled to control the quality of videos published on their online HSN sites. The HealthTrust metric was selected as the metric to be implemented in the service in order to support the assessment of trustworthiness of videos in Online HSN. The service is a RESTful service which can be integrated into open source Virtual Social Network Platforms, therefore improving trust in the process of searching and publishing content extracted from YouTube. A preliminary pilot evaluation in a simple use case demonstrated that the relevance of videos retrieved using the moderation service was higher compared to the relevance of the videos retrieved using the YouTube search engine.
Reliability of a visual scoring system with fluorescent tracers to assess dermal pesticide exposure.
Aragon, Aurora; Blanco, Luis; Lopez, Lylliam; Liden, Carola; Nise, Gun; Wesseling, Catharina
2004-10-01
We modified Fenske's semi-quantitative 'visual scoring system' of fluorescent tracer deposited on the skin of pesticide applicators and evaluated its reproducibility in the Nicaraguan setting. The body surface of 33 farmers, divided into 31 segments, was videotaped in the field after spraying with a pesticide solution containing a fluorescent tracer. A portable UV lamp was used for illumination in a foldaway dark room. The videos of five farmers were randomly selected. The scoring was based on a matrix with extension of fluorescent patterns (scale 0-5) on the ordinate and intensity (scale 0-5) on the abscissa, with the product of these two ranks as the final score for each body segment (0-25). Five medical students rated and evaluated the quality of 155 video images having undergone 4 h of training. Cronbach alpha coefficients and two-way random effects intraclass correlation coefficients (ICC) with absolute agreement were computed to assess inter-rater reliability. Consistency was high (Cronbach alpha = 0.96), but the scores differed substantially between raters. The overall ICC was satisfactory [0.75; 95% confidence interval (CI) = 0.62-0.83], but it was lower for intensity (0.54; 95% CI = 0.40-0.66) and higher for extension (0.80; 95% CI = 0.71-0.86). ICCs were lowest for images with low scores and evaluated as low quality, and highest for images with high scores and high quality. Inter-rater reliability coefficients indicate repeatability of the scoring system. However, field conditions for recording fluorescence should be improved to achieve higher quality images, and training should emphasize a better mechanism for the reading of body areas with low contamination.
The Endockscope Using Next Generation Smartphones: "A Global Opportunity".
Tse, Christina; Patel, Roshan M; Yoon, Renai; Okhunov, Zhamshid; Landman, Jaime; Clayman, Ralph V
2018-06-02
The Endockscope combines a smartphone, a battery powered flashlight and a fiberoptic cystoscope allowing for mobile videocystoscopy. We compared conventional videocystoscopy to the Endockscope paired with next generation smartphones in an ex-vivo porcine bladder model to evaluate its image quality. The Endockscope consists of a three-dimensional (3D) printed attachment that connects a smartphone to a flexible fiberoptic cystoscope plus a 1000 lumen light-emitting diode (LED) cordless light source. Video recordings of porcine cystoscopy with a fiberoptic flexible cystoscope (Storz) were captured for each mobile device (iPhone 6, iPhone 6S, iPhone 7, Samsung S8, and Google Pixel) and for the high-definition H3-Z versatile camera (HD) set-up with both the LED light source and the xenon light (XL) source. Eleven faculty urologists, blinded to the modality used, evaluated each video for image quality/resolution, brightness, color quality, sharpness, overall quality, and acceptability for diagnostic use. When comparing the Endockscope coupled to an Galaxy S8, iPhone 7, and iPhone 6S with the LED portable light source to the HD camera with XL, there were no statistically significant differences in any metric. 82% and 55% of evaluators considered the iPhone 7 + LED light source and iPhone 6S + LED light, respectively, appropriate for diagnostic purposes as compared to 100% who considered the HD camera with XL appropriate. The iPhone 6 and Google Pixel coupled with the LED source were both inferior to the HD camera with XL in all metrics. The Endockscope system with a LED light source when coupled with either an iPhone 7 or Samsung S8 (total cost: $750) is comparable to conventional videocystoscopy with a standard camera and XL light source (total cost: $45,000).
ERIC Educational Resources Information Center
Desmarais, Norman
1991-01-01
Reviews current developments in multimedia computing for both the business and consumer markets, including interactive multimedia players; compact disc-interactive (CD-I), including levels of audio quality, various video specifications and visual effects, and software; digital video interactive (DVI); and multimedia personal computers. (LRW)
Underwater video enhancement using multi-camera super-resolution
NASA Astrophysics Data System (ADS)
Quevedo, E.; Delory, E.; Callicó, G. M.; Tobajas, F.; Sarmiento, R.
2017-12-01
Image spatial resolution is critical in several fields such as medicine, communications or satellite, and underwater applications. While a large variety of techniques for image restoration and enhancement has been proposed in the literature, this paper focuses on a novel Super-Resolution fusion algorithm based on a Multi-Camera environment that permits to enhance the quality of underwater video sequences without significantly increasing computation. In order to compare the quality enhancement, two objective quality metrics have been used: PSNR (Peak Signal-to-Noise Ratio) and the SSIM (Structural SIMilarity) index. Results have shown that the proposed method enhances the objective quality of several underwater sequences, avoiding the appearance of undesirable artifacts, with respect to basic fusion Super-Resolution algorithms.
Constructing storyboards based on hierarchical clustering analysis
NASA Astrophysics Data System (ADS)
Hasebe, Satoshi; Sami, Mustafa M.; Muramatsu, Shogo; Kikuchi, Hisakazu
2005-07-01
There are growing needs for quick preview of video contents for the purpose of improving accessibility of video archives as well as reducing network traffics. In this paper, a storyboard that contains a user-specified number of keyframes is produced from a given video sequence. It is based on hierarchical cluster analysis of feature vectors that are derived from wavelet coefficients of video frames. Consistent use of extracted feature vectors is the key to avoid a repetition of computationally-intensive parsing of the same video sequence. Experimental results suggest that a significant reduction in computational time is gained by this strategy.
Distributed Patterns of Reactivation Predict Vividness of Recollection.
St-Laurent, Marie; Abdi, Hervé; Buchsbaum, Bradley R
2015-10-01
According to the principle of reactivation, memory retrieval evokes patterns of brain activity that resemble those instantiated when an event was first experienced. Intuitively, one would expect neural reactivation to contribute to recollection (i.e., the vivid impression of reliving past events), but evidence of a direct relationship between the subjective quality of recollection and multiregional reactivation of item-specific neural patterns is lacking. The current study assessed this relationship using fMRI to measure brain activity as participants viewed and mentally replayed a set of short videos. We used multivoxel pattern analysis to train a classifier to identify individual videos based on brain activity evoked during perception and tested how accurately the classifier could distinguish among videos during mental replay. Classification accuracy correlated positively with memory vividness, indicating that the specificity of multivariate brain patterns observed during memory retrieval was related to the subjective quality of a memory. In addition, we identified a set of brain regions whose univariate activity during retrieval predicted both memory vividness and the strength of the classifier's prediction irrespective of the particular video that was retrieved. Our results establish distributed patterns of neural reactivation as a valid and objective marker of the quality of recollection.
Motion adaptive Kalman filter for super-resolution
NASA Astrophysics Data System (ADS)
Richter, Martin; Nasse, Fabian; Schröder, Hartmut
2011-01-01
Superresolution is a sophisticated strategy to enhance image quality of both low and high resolution video, performing tasks like artifact reduction, scaling and sharpness enhancement in one algorithm, all of them reconstructing high frequency components (above Nyquist frequency) in some way. Especially recursive superresolution algorithms can fulfill high quality aspects because they control the video output using a feed-back loop and adapt the result in the next iteration. In addition to excellent output quality, temporal recursive methods are very hardware efficient and therefore even attractive for real-time video processing. A very promising approach is the utilization of Kalman filters as proposed by Farsiu et al. Reliable motion estimation is crucial for the performance of superresolution. Therefore, robust global motion models are mainly used, but this also limits the application of superresolution algorithm. Thus, handling sequences with complex object motion is essential for a wider field of application. Hence, this paper proposes improvements by extending the Kalman filter approach using motion adaptive variance estimation and segmentation techniques. Experiments confirm the potential of our proposal for ideal and real video sequences with complex motion and further compare its performance to state-of-the-art methods like trainable filters.
Communication system analysis for manned space flight
NASA Technical Reports Server (NTRS)
Schilling, D. L.
1978-01-01
The development of adaptive delta modulators capable of digitizing a video signal is summarized. The delta modulator encoder accepts a 4 MHz black and white composite video signal or a color video signal and encodes it into a stream of binary digits at a rate which can be adjusted from 8 Mb/s to 24 Mb/s. The output bit rate is determined by the user and alters the quality of the video picture. The digital signal is decoded using the adaptive delta modulator decoder to reconstruct the picture.
Using Online Digital Tools and Video to Support International Problem-Based Learning
ERIC Educational Resources Information Center
Lajoie, Susanne P.; Hmelo-Silver, Cindy; Wiseman, Jeffrey; Chan, Lap Ki; Lu, Jingyan; Khurana, Chesta; Cruz-Panesso, Ilian; Poitras, Eric; Kazemitabar, Maedeh
2014-01-01
The goal of this study is to examine how to facilitate cross-cultural groups in problem-based learning (PBL) using online digital tools and videos. The PBL consisted of two video-based cases used to trigger student-learning issues about giving bad news to HIV-positive patients. Mixed groups of medical students from Canada and Hong Kong worked with…
ERIC Educational Resources Information Center
Lambeth, Ellen; Westervelt, Miriam O.
This instructional guide (accompanied by a video) teaches children from ages 6 to 12 about wildlife habitats. The instructional guide is divided into four parts and consists of supplementary activities to enhance the video. Each section of the guide provides an overview, objectives, story summary, key words in the video, discussion questions,…
ERIC Educational Resources Information Center
Ward, Stephen; Pellet, Heidi Henschel; Perez, Mark I.
2017-01-01
Purpose: The purpose of this study was to explore preservice teachers' experiences of cognitive disequilibrium (CD) theory during a service-learning project in a study abroad experience. Method: A case study with 8 participants was used. Data sources consisted of: Formal interviews, videos of planning, videos of teaching, videos of reflection…
Using of Video Modeling in Teaching a Simple Meal Preparation Skill for Pupils of Down Syndrome
ERIC Educational Resources Information Center
AL-Salahat, Mohammad Mousa
2016-01-01
The current study aimed to identify the impact of video modeling upon teaching three pupils with Down syndrome the skill of preparing a simple meal (sandwich), where the training was conducted in a separate classroom in schools of normal students. The training consisted of (i) watching the video of an intellectually disabled pupil, who is…
Perceptual quality estimation of H.264/AVC videos using reduced-reference and no-reference models
NASA Astrophysics Data System (ADS)
Shahid, Muhammad; Pandremmenou, Katerina; Kondi, Lisimachos P.; Rossholm, Andreas; Lövström, Benny
2016-09-01
Reduced-reference (RR) and no-reference (NR) models for video quality estimation, using features that account for the impact of coding artifacts, spatio-temporal complexity, and packet losses, are proposed. The purpose of this study is to analyze a number of potentially quality-relevant features in order to select the most suitable set of features for building the desired models. The proposed sets of features have not been used in the literature and some of the features are used for the first time in this study. The features are employed by the least absolute shrinkage and selection operator (LASSO), which selects only the most influential of them toward perceptual quality. For comparison, we apply feature selection in the complete feature sets and ridge regression on the reduced sets. The models are validated using a database of H.264/AVC encoded videos that were subjectively assessed for quality in an ITU-T compliant laboratory. We infer that just two features selected by RR LASSO and two bitstream-based features selected by NR LASSO are able to estimate perceptual quality with high accuracy, higher than that of ridge, which uses more features. The comparisons with competing works and two full-reference metrics also verify the superiority of our models.
A Method for Developing Standard Patient Education Program.
Lura, Carolina Bryne; Hauch, Sophie Misser Pallesgaard; Gøeg, Kirstine Rosenbeck; Pape-Haugaard, Louise
2018-01-01
In Denmark, patients being treated on Haematology Outpatients Departments get instructed to self-manage their blood sample collection from Central Venous Catheter (CVC). However, this is a complex and risky procedure, which can jeopardize patient safety. The aim of the study was to suggest a method for developing standard digital patient education programs for patients in self-administration of blood samples drawn from CVC. The Design Science Research Paradigm was used to develop a digital patient education program, called PAVIOSY, to increase patient safety during execution of the blood sample collection procedure by using videos for teaching as well as procedural support. A step-by-step guide was developed and used as basis for making the videos. Quality assurance through evaluation with a nurse was conducted on both the step-by-step guide and the videos. The quality assurance evaluation of the videos showed; 1) Errors due to the order of the procedure can be determined by reviewing the videos despite that the guide was followed. 2) Videos can be used to identify errors - important for patient safety - in the procedure, which are not identifiable in a written script. To ensure correct clinical content of the educational patient system, health professionals must be engaged early in the development of content and design phase.
Design of video interface conversion system based on FPGA
NASA Astrophysics Data System (ADS)
Zhao, Heng; Wang, Xiang-jun
2014-11-01
This paper presents a FPGA based video interface conversion system that enables the inter-conversion between digital and analog video. Cyclone IV series EP4CE22F17C chip from Altera Corporation is used as the main video processing chip, and single-chip is used as the information interaction control unit between FPGA and PC. The system is able to encode/decode messages from the PC. Technologies including video decoding/encoding circuits, bus communication protocol, data stream de-interleaving and de-interlacing, color space conversion and the Camera Link timing generator module of FPGA are introduced. The system converts Composite Video Broadcast Signal (CVBS) from the CCD camera into Low Voltage Differential Signaling (LVDS), which will be collected by the video processing unit with Camera Link interface. The processed video signals will then be inputted to system output board and displayed on the monitor.The current experiment shows that it can achieve high-quality video conversion with minimum board size.
Henry, Stephen G.; Fetters, Michael D.
2012-01-01
We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants’ associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care. PMID:22412003
Henry, Stephen G; Fetters, Michael D
2012-01-01
We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants' associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care.
Video streaming with SHVC to HEVC transcoding
NASA Astrophysics Data System (ADS)
Gudumasu, Srinivas; He, Yuwen; Ye, Yan; Xiu, Xiaoyu
2015-09-01
This paper proposes an efficient Scalable High efficiency Video Coding (SHVC) to High Efficiency Video Coding (HEVC) transcoder, which can reduce the transcoding complexity significantly, and provide a desired trade-off between the transcoding complexity and the transcoded video quality. To reduce the transcoding complexity, some of coding information, such as coding unit (CU) depth, prediction mode, merge mode, motion vector information, intra direction information and transform unit (TU) depth information, in the SHVC bitstream are mapped and transcoded to single layer HEVC bitstream. One major difficulty in transcoding arises when trying to reuse the motion information from SHVC bitstream since motion vectors referring to inter-layer reference (ILR) pictures cannot be reused directly in transcoding. Reusing motion information obtained from ILR pictures for those prediction units (PUs) will reduce the complexity of the SHVC transcoder greatly but a significant reduction in the quality of the picture is observed. Pictures corresponding to the intra refresh pictures in the base layer (BL) will be coded as P pictures in enhancement layer (EL) in the SHVC bitstream; and directly reusing the intra information from the BL for transcoding will not get a good coding efficiency. To solve these problems, various transcoding technologies are proposed. The proposed technologies offer different trade-offs between transcoding speed and transcoding quality. They are implemented on the basis of reference software SHM-6.0 and HM-14.0 for the two layer spatial scalability configuration. Simulations show that the proposed SHVC software transcoder reduces the transcoding complexity by up to 98-99% using low complexity transcoding mode when compared with cascaded re-encoding method. The transcoder performance at various bitrates with different transcoding modes are compared in terms of transcoding speed and transcoded video quality.
Water surface modeling from a single viewpoint video.
Li, Chuan; Pickup, David; Saunders, Thomas; Cosker, Darren; Marshall, David; Hall, Peter; Willis, Philip
2013-07-01
We introduce a video-based approach for producing water surface models. Recent advances in this field output high-quality results but require dedicated capturing devices and only work in limited conditions. In contrast, our method achieves a good tradeoff between the visual quality and the production cost: It automatically produces a visually plausible animation using a single viewpoint video as the input. Our approach is based on two discoveries: first, shape from shading (SFS) is adequate to capture the appearance and dynamic behavior of the example water; second, shallow water model can be used to estimate a velocity field that produces complex surface dynamics. We will provide qualitative evaluation of our method and demonstrate its good performance across a wide range of scenes.
NASA Astrophysics Data System (ADS)
Myszkowski, Karol; Tawara, Takehiro; Seidel, Hans-Peter
2002-06-01
In this paper, we consider applications of perception-based video quality metrics to improve the performance of global lighting computations for dynamic environments. For this purpose we extend the Visible Difference Predictor (VDP) developed by Daly to handle computer animations. We incorporate into the VDP the spatio-velocity CSF model developed by Kelly. The CSF model requires data on the velocity of moving patterns across the image plane. We use the 3D image warping technique to compensate for the camera motion, and we conservatively assume that the motion of animated objects (usually strong attractors of the visual attention) is fully compensated by the smooth pursuit eye motion. Our global illumination solution is based on stochastic photon tracing and takes advantage of temporal coherence of lighting distribution, by processing photons both in the spatial and temporal domains. The VDP is used to keep noise inherent in stochastic methods below the sensitivity level of the human observer. As a result a perceptually-consistent quality across all animation frames is obtained.
Multimedia systems for art and culture: a case study of Brihadisvara Temple
NASA Astrophysics Data System (ADS)
Jain, Anil K.; Goel, Sanjay; Agarwal, Sachin; Mittal, Vipin; Sharma, Hariom; Mahindru, Ranjeev
1997-01-01
In India a temple is not only a structure of religious significance and celebration, but it also plays an important role in the social, administrative and cultural life of the locality. Temples have served as centers for learning Indian scriptures. Music and dance were fostered and performed in the precincts of the temples. Built at the end of the 10th century, the Brihadisvara temple signified new design methodologies. We have access to a large number of images, audio and video recordings, architectural drawings and scholarly publications of this temple. A multimedia system for this temple is being designed which is intended to be used for the following purposes: (1) to inform and enrich the general public, and (2) to assist the scholars in their research. Such a system will also preserve and archive old historical documents and images. The large database consists primarily of images which can be retrieved using keywords, but the emphasis here is largely on techniques which will allow access using image content. Besides classifying images as either long shots or close-ups, deformable template matching is used for shape-based query by image content, and digital video retrieval. Further, to exploit the non-linear accessibility of video sequences, key frames are determined to aid the domain experts in getting a quick preview of the video. Our database also has images of several old, and rare manuscripts many of which are noisy and difficult to read. We have enhanced them to make them more legible. We are also investigating the optimal trade-off between image quality and compression ratios.
Active video gaming in patients with renal transplant: a pilot study
2014-01-01
Background Patients with renal transplant are at higher risk of mortality from cardiovascular disease (CVD) compared with the general population. Physical activity has been shown to reduce the risk of CVD mortality in these patients. Unfortunately, barriers such as the harsh Canadian climate prevent patients from engaging in and harvesting the health benefits of physical activity. This pilot study explored active video gaming (AVG) as a way for patients with renal transplant to obtain physical activity and examined its effect on their functional status and quality of life (QOL). Main text We recruited nine patients for an 8-week prospective pilot study. All patients received a Microsoft Xbox 360™ video gaming console, a Microsoft Kinect™ sensor, and the video game Your Shape Fitness Evolved 2012. Assessment of each participant before and after the intervention included blood pressure measures, a 6-minute walk test, and the Godin Leisure Time Questionnaire (GLTQ). We analyzed all nine patients at the end of the 8-week study period, and found no changes in blood pressure or GLTQ scores. However, there was a significant increase in the 6-minute walk distance (P = 0.022), which represented a consistent increase for most patients (correlation = 0.977). In addition, participants over the age of 45 years (n = 4) were more likely to use the AVG system (P = 0.042). Conclusion AVG has the potential to improve the functional status in patients with renal transplant. Further research is required to corroborate the full health benefits of AVG in this patient population. PMID:25114788
HDR video synthesis for vision systems in dynamic scenes
NASA Astrophysics Data System (ADS)
Shopovska, Ivana; Jovanov, Ljubomir; Goossens, Bart; Philips, Wilfried
2016-09-01
High dynamic range (HDR) image generation from a number of differently exposed low dynamic range (LDR) images has been extensively explored in the past few decades, and as a result of these efforts a large number of HDR synthesis methods have been proposed. Since HDR images are synthesized by combining well-exposed regions of the input images, one of the main challenges is dealing with camera or object motion. In this paper we propose a method for the synthesis of HDR video from a single camera using multiple, differently exposed video frames, with circularly alternating exposure times. One of the potential applications of the system is in driver assistance systems and autonomous vehicles, involving significant camera and object movement, non- uniform and temporally varying illumination, and the requirement of real-time performance. To achieve these goals simultaneously, we propose a HDR synthesis approach based on weighted averaging of aligned radiance maps. The computational complexity of high-quality optical flow methods for motion compensation is still pro- hibitively high for real-time applications. Instead, we rely on more efficient global projective transformations to solve camera movement, while moving objects are detected by thresholding the differences between the trans- formed and brightness adapted images in the set. To attain temporal consistency of the camera motion in the consecutive HDR frames, the parameters of the perspective transformation are stabilized over time by means of computationally efficient temporal filtering. We evaluated our results on several reference HDR videos, on synthetic scenes, and using 14-bit raw images taken with a standard camera.
Quality metric for spherical panoramic video
NASA Astrophysics Data System (ADS)
Zakharchenko, Vladyslav; Choi, Kwang Pyo; Park, Jeong Hoon
2016-09-01
Virtual reality (VR)/ augmented reality (AR) applications allow users to view artificial content of a surrounding space simulating presence effect with a help of special applications or devices. Synthetic contents production is well known process form computer graphics domain and pipeline has been already fixed in the industry. However emerging multimedia formats for immersive entertainment applications such as free-viewpoint television (FTV) or spherical panoramic video require different approaches in content management and quality assessment. The international standardization on FTV has been promoted by MPEG. This paper is dedicated to discussion of immersive media distribution format and quality estimation process. Accuracy and reliability of the proposed objective quality estimation method had been verified with spherical panoramic images demonstrating good correlation results with subjective quality estimation held by a group of experts.
Methodology for stereoscopic motion-picture quality assessment
NASA Astrophysics Data System (ADS)
Voronov, Alexander; Vatolin, Dmitriy; Sumin, Denis; Napadovsky, Vyacheslav; Borisov, Alexey
2013-03-01
Creating and processing stereoscopic video imposes additional quality requirements related to view synchronization. In this work we propose a set of algorithms for detecting typical stereoscopic-video problems, which appear owing to imprecise setup of capture equipment or incorrect postprocessing. We developed a methodology for analyzing the quality of S3D motion pictures and for revealing their most problematic scenes. We then processed 10 modern stereo films, including Avatar, Resident Evil: Afterlife and Hugo, and analyzed changes in S3D-film quality over the years. This work presents real examples of common artifacts (color and sharpness mismatch, vertical disparity and excessive horizontal disparity) in the motion pictures we processed, as well as possible solutions for each problem. Our results enable improved quality assessment during the filming and postproduction stages.
NASA Astrophysics Data System (ADS)
Arciniegas, Javier R.; González, Andrés. L.; Quintero, L. A.; Contreras, Carlos R.; Meneses, Jaime E.
2014-05-01
Three-dimensional shape measurement is a subject that consistently produces high scientific interest and provides information for medical, industrial and investigative applications, among others. In this paper, it is proposed to implement a three-dimensional (3D) reconstruction system for applications in superficial inspection of non-metallic pipes for the hydrocarbons transport. The system is formed by a CCD camera, a video-projector and a laptop and it is based on fringe projection technique. System functionality is evidenced by evaluating the quality of three-dimensional reconstructions obtained, which allow observing the failures and defects on the study object surface.
The Important Elements of a Science Video
NASA Astrophysics Data System (ADS)
Harned, D. A.; Moorman, M.; McMahon, G.
2012-12-01
New technologies have revolutionized use of video as a means of communication. Films have become easier to create and to distribute. Video is omnipresent in our culture and supplements or even replaces writing in many applications. How can scientists and educators best use video to communicate scientific results? Video podcasts are being used in addition to journal, print, and online publications to communicate the relevance of scientific findings of the U.S. Geological Survey's (USGS) National Water-Quality Assessment (NAWQA) program to general audiences such as resource managers, educational groups, public officials, and the general public. In an effort to improve the production of science videos a survey was developed to provide insight into effective science communication with video. Viewers of USGS podcast videos were surveyed using Likert response- scaling to identify the important elements of science videos. The surveys were of 120 scientists and educators attending the 2010 and 2011 Fall Meetings of the American Geophysical Union and the 2012 meeting of the National Monitoring Council. The median age of the respondents was 44 years, with an education level of a Bachelor's Degree or higher. Respondents reported that their primary sources for watching science videos were YouTube and science websites. Video length was the single most important element associated with reaching the greatest number of viewers. The surveys indicated a median length of 5 minutes as appropriate for a web video, with 5-7 minutes the 25th-75th percentiles. An illustration of the effect of length: a 5-minute and a 20-minute version of a USGS film on the effect of urbanization on water-quality was made available on the same website. The short film has been downloaded 3 times more frequently than the longer film version. The survey showed that the most important elements to include in a science film are style elements including strong visuals, an engaging story, and a simple message, and elements of substance including clarity, believability, and a take-home message. The least important are journalistic elements such as showing different points of view and obstacles overcome. The survey respondents also considered inclusion of a hypothesis statement and study methods unnecessary in a science video.
Tiny videos: a large data set for nonparametric video retrieval and frame classification.
Karpenko, Alexandre; Aarabi, Parham
2011-03-01
In this paper, we present a large database of over 50,000 user-labeled videos collected from YouTube. We develop a compact representation called "tiny videos" that achieves high video compression rates while retaining the overall visual appearance of the video as it varies over time. We show that frame sampling using affinity propagation-an exemplar-based clustering algorithm-achieves the best trade-off between compression and video recall. We use this large collection of user-labeled videos in conjunction with simple data mining techniques to perform related video retrieval, as well as classification of images and video frames. The classification results achieved by tiny videos are compared with the tiny images framework [24] for a variety of recognition tasks. The tiny images data set consists of 80 million images collected from the Internet. These are the largest labeled research data sets of videos and images available to date. We show that tiny videos are better suited for classifying scenery and sports activities, while tiny images perform better at recognizing objects. Furthermore, we demonstrate that combining the tiny images and tiny videos data sets improves classification precision in a wider range of categories.
Couch kids: correlates of television viewing among youth.
Gorely, Trish; Marshall, Simon J; Biddle, Stuart J H
2004-01-01
The purpose of this study was to review the published empirical correlates of television/video viewing among youth (2 to 18 years). A descriptive semi-quantitative review was conducted based on 68 primary studies. Variables consistently associated with TV/video viewing were ethnicity (non-white +), parent income (-), parent education (-), body weight (+), between meal snacking (+), number of parents in the house (-), parents TV viewing habits (+), weekend (+) and having a TV in the bedroom (+). Variables consistently unrelated to TV/video viewing were sex, other indicators of socio-economic status, body fatness, cholesterol levels, aerobic fitness, strength, other indicators of fitness, self-perceptions, emotional support, physical activity, other diet variables, and being an only child. Few modifiable correlates have been identified. Further research should aim to identify modifiable correlates of TV/video viewing if interventions are to be successfully tailored to reduce this aspect of inactivity among youth.
Selective visual region of interest to enhance medical video conferencing
NASA Astrophysics Data System (ADS)
Bonneau, Walt, Jr.; Read, Christopher J.; Shirali, Girish
1998-06-01
The continued economic pressure that is being placed upon the healthcare industry creates both challenge and opportunity to develop cost effective healthcare tools. Tools that provide improvements in the quality of medical care at the same time improve the distribution of efficient care will create product demand. Video Conferencing systems are one of the latest product technologies that are evolving their way into healthcare applications. The systems that provide quality Bi- directional video and imaging at the lowest system and communication cost are creating many possible options for the healthcare industry. A method to use only 128k bits/sec. of ISDN bandwidth while providing quality video images in selected regions will be applied to echocardiograms using a low cost video conferencing system operating within a basic rate ISDN line bandwidth. Within a given display area (frame) it has been observed that only selected informational areas of the frame of are of value when viewing for detail and precision within an image. Much in the same manner that a photograph is cropped. If a method to accomplish Region Of Interest (ROI) was applied to video conferencing using H.320 with H.263 (compression) and H.281 (camera control) international standards, medical image quality could be achieved in a cost-effective manner. For example, the cardiologist could be provided with a selectable three to eight end-point viewable ROI polygon that defines the ROI in the image. This is achieved by the video system calculating the selected regional end-points and creating an alpha mask to signify the importance of the ROI to the compression processor. This region is then applied to the compression algorithm in a manner that the majority of the video conferencing processor cycles are focused on the ROI of the image. An occasional update of the non-ROI area is processed to maintain total image coherence. The user could control the non-ROI area updates. Providing encoder side ROI specification is of value. However, the power of this capability is improved if remote access and selection of the ROI is also provided. Using the H.281 camera standard and proposing an additional option to the standard to allow for remote ROI selection would make this possible. When ROI is applied the ability to reach the equivalent of 384K bits/sec ISDN rates may be achieved or exceeded depending upon the size of the selected ROI using 128K bits/sec. This opens additional opportunity to establish international calling and reduced call rates by up to sixty- six percent making reoccurring communication costs attractive. Rates of twenty to thirty quality ROI updates could be achieved. It is however important to understand that this technique is still under development.
Emergency Video Telemedicine Consultation for Newborn Resuscitations: The Mayo Clinic Experience.
Fang, Jennifer L; Collura, Christopher A; Johnson, Robert V; Asay, Garth F; Carey, William A; Derleth, Douglas P; Lang, Tara R; Kreofsky, Beth L; Colby, Christopher E
2016-12-01
To describe the Mayo Clinic experience with emergency video telemedicine consultations for high-risk newborn deliveries. From March 26, 2013, through December 31, 2015, the Division of Neonatal Medicine offered newborn telemedicine consultations to 6 health system sites. A wireless tablet running secure video conferencing software was used by the local care teams. Descriptive data were collected on all consultations. After each telemedicine consult, a survey was sent to the neonatologist and referring provider to assess the technology, teamwork, and user satisfaction. During the study, neonatologists conducted 84 telemedicine consultations, and 64 surveys were completed. Prematurity was the most frequent indication for consultation (n=32), followed by respiratory distress (n=15) and need for advanced resuscitation (n=14). After the consult, nearly one-third of the infants were able to remain in the local hospital. User assessment of the technology revealed that audio and video quality were poor or unusable in 16 (25%) and 12 (18.8%) of cases, respectively. Providers failed to establish a video connection in 8 consults (9.5%). Despite technical issues, providers responded positively to multiple questions assessing teamwork (86.0% [n=37 of 43] to 100.0% [n=17 of 17] positive responses per question). In 93.3% (n=14 of 15) of surveyed cases, the local provider agreed that the telemedicine consult improved patient safety, quality of care, or both. Telemedicine consultation for neonatal resuscitation improves patient access to neonatology expertise and prevents unnecessary transfers to a higher level of care. A highly reliable technology infrastructure that provides high-quality audio and video should be considered for any emergency telemedicine service. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
Looking Tasks Online: Utilizing Webcams to Collect Video Data from Home
Semmelmann, Kilian; Hönekopp, Astrid; Weigelt, Sarah
2017-01-01
Online experimentation is emerging as a new methodology within classical data acquisition in psychology. It allows for easy, fast, broad, and cheap data conduction from the comfort of people’s homes. To add another method to the array of available tools, here we used recent developments in web technology to investigate the technical feasibility of online HyperText Markup Language-5/JavaScript-based video data recording. We employed a preferential looking task with children between 4 and 24 months. Parents and their children participated from home through a three-stage process: First, interested adults registered and took pictures through a webcam-based photo application. In the second step, we edited the pictures and integrated them into the design. Lastly, participants returned to the website and the video data acquisition took place through their webcam. In sum, we were able to create and employ the video recording application with participants as young as 4 months old. Quality-wise, no participant had to be removed due to the framerate or quality of videos and only 7% of data was excluded due to behavioral factors (lack of concentration). Results-wise, interrater reliability of rated looking side (left/right) showed a high agreement between raters, Fleiss’ Kappa, κ = 0.97, which can be translated to sufficient data quality for further analyses. With regard to on-/off-screen attention attribution, we found that children lost interest after about 10 s after trial onset using a static image presentation or 60 s total experimental time. Taken together, we were able to show that online video data recording is possible and viable for developmental psychology and beyond. PMID:28955284
Looking Tasks Online: Utilizing Webcams to Collect Video Data from Home.
Semmelmann, Kilian; Hönekopp, Astrid; Weigelt, Sarah
2017-01-01
Online experimentation is emerging as a new methodology within classical data acquisition in psychology. It allows for easy, fast, broad, and cheap data conduction from the comfort of people's homes. To add another method to the array of available tools, here we used recent developments in web technology to investigate the technical feasibility of online HyperText Markup Language-5/JavaScript-based video data recording. We employed a preferential looking task with children between 4 and 24 months. Parents and their children participated from home through a three-stage process: First, interested adults registered and took pictures through a webcam-based photo application. In the second step, we edited the pictures and integrated them into the design. Lastly, participants returned to the website and the video data acquisition took place through their webcam. In sum, we were able to create and employ the video recording application with participants as young as 4 months old. Quality-wise, no participant had to be removed due to the framerate or quality of videos and only 7% of data was excluded due to behavioral factors (lack of concentration). Results-wise, interrater reliability of rated looking side (left/right) showed a high agreement between raters, Fleiss' Kappa, κ = 0.97, which can be translated to sufficient data quality for further analyses. With regard to on-/off-screen attention attribution, we found that children lost interest after about 10 s after trial onset using a static image presentation or 60 s total experimental time. Taken together, we were able to show that online video data recording is possible and viable for developmental psychology and beyond.
A simulator tool set for evaluating HEVC/SHVC streaming
NASA Astrophysics Data System (ADS)
Al Hadhrami, Tawfik; Nightingale, James; Wang, Qi; Grecos, Christos; Kehtarnavaz, Nasser
2015-02-01
Video streaming and other multimedia applications account for an ever increasing proportion of all network traffic. The recent adoption of High Efficiency Video Coding (HEVC) as the H.265 standard provides many opportunities for new and improved services multimedia services and applications in the consumer domain. Since the delivery of version one of H.265, the Joint Collaborative Team on Video Coding have been working towards standardisation of a scalable extension (SHVC) to the H.265 standard and a series of range extensions and new profiles. As these enhancements are added to the standard the range of potential applications and research opportunities will expend. For example the use of video is also growing rapidly in other sectors such as safety, security, defence and health with real-time high quality video transmission playing an important role in areas like critical infrastructure monitoring and disaster management. Each of which may benefit from the application of enhanced HEVC/H.265 and SHVC capabilities. The majority of existing research into HEVC/H.265 transmission has focussed on the consumer domain addressing issues such as broadcast transmission and delivery to mobile devices with the lack of freely available tools widely cited as an obstacle to conducting this type of research. In this paper we present a toolset which facilitates the transmission and evaluation of HEVC/H.265 and SHVC encoded video on the popular open source NCTUns simulator. Our toolset provides researchers with a modular, easy to use platform for evaluating video transmission and adaptation proposals on large scale wired, wireless and hybrid architectures. The toolset consists of pre-processing, transmission, SHVC adaptation and post-processing tools to gather and analyse statistics. It has been implemented using HM15 and SHM5, the latest versions of the HEVC and SHVC reference software implementations to ensure that currently adopted proposals for scalable and range extensions to the standard can be investigated. We demonstrate the effectiveness and usability of our toolset by evaluating SHVC streaming and adaptation to meet terminal constraints and network conditions in a range of wired, wireless, and large scale wireless mesh network scenarios, each of which is designed to simulate a realistic environment. Our results are compared to those for H264/SVC, the scalable extension to the existing H.264/AVC advanced video coding standard.
Quantitative evaluation of low-cost frame-grabber boards for personal computers.
Kofler, J M; Gray, J E; Fuelberth, J T; Taubel, J P
1995-11-01
Nine moderately priced frame-grabber boards for both Macintosh (Apple Computers, Cupertino, CA) and IBM-compatible computers were evaluated using a Society of Motion Pictures and Television Engineers (SMPTE) pattern and a video signal generator for dynamic range, gray-scale reproducibility, and spatial integrity of the captured image. The degradation of the video information ranged from minor to severe. Some boards are of reasonable quality for applications in diagnostic imaging and education. However, price and quality are not necessarily directly related.
Educational Video Recording and Editing for The Hand Surgeon
Rehim, Shady A.; Chung, Kevin C.
2016-01-01
Digital video recordings are increasingly used across various medical and surgical disciplines including hand surgery for documentation of patient care, resident education, scientific presentations and publications. In recent years, the introduction of sophisticated computer hardware and software technology has simplified the process of digital video production and improved means of disseminating large digital data files. However, the creation of high quality surgical video footage requires basic understanding of key technical considerations, together with creativity and sound aesthetic judgment of the videographer. In this article we outline the practical steps involved with equipment preparation, video recording, editing and archiving as well as guidance for the choice of suitable hardware and software equipment. PMID:25911212
Naumann, David N; Mellis, Clare; Smith, Iain M; Mamuza, Jasna; Skene, Imogen; Harris, Tim; Midwinter, Mark J; Hutchings, Sam D
2016-01-01
Objectives Sublingual microcirculatory monitoring for traumatic haemorrhagic shock (THS) may predict clinical outcomes better than traditional blood pressure and cardiac output, but is not usually performed until the patient reaches the intensive care unit (ICU), missing earlier data of potential importance. This pilot study assessed for the first time the feasibility and safety of sublingual video-microscopy for THS in the emergency department (ED), and whether it yields useable data for analysis. Setting A safety and feasibility assessment was undertaken as part of the prospective observational MICROSHOCK study; sublingual video-microscopy was performed at the UK-led Role 3 medical facility at Camp Bastion, Afghanistan, and in the ED in 3 UK Major Trauma Centres. Participants There were 15 casualties (2 military, 13 civilian) who presented with traumatic haemorrhagic shock with a median injury severity score of 26. The median age was 41; the majority (n=12) were male. The most common injury mechanism was road traffic accident. Primary and secondary outcome measures Safety and feasibility were the primary outcomes, as measured by lack of adverse events or clinical interruptions, and successful acquisition and storage of data. The secondary outcome was the quality of acquired video clips according to validated criteria, in order to determine whether useful data could be obtained in this emergency context. Results Video-microscopy was successfully performed and stored for analysis for all patients, yielding 161 video clips. There were no adverse events or episodes where clinical management was affected or interrupted. There were 104 (64.6%) video clips from 14 patients of sufficient quality for analysis. Conclusions Early sublingual microcirculatory monitoring in the ED for patients with THS is safe and feasible, even in a deployed military setting, and yields videos of satisfactory quality in a high proportion of cases. Further investigations of early microcirculatory behaviour in this context are warranted. Trial registration number NCT02111109. PMID:28003301
Wireless live streaming video of laparoscopic surgery: a bandwidth analysis for handheld computers.
Gandsas, Alex; McIntire, Katherine; George, Ivan M; Witzke, Wayne; Hoskins, James D; Park, Adrian
2002-01-01
Over the last six years, streaming media has emerged as a powerful tool for delivering multimedia content over networks. Concurrently, wireless technology has evolved, freeing users from desktop boundaries and wired infrastructures. At the University of Kentucky Medical Center, we have integrated these technologies to develop a system that can wirelessly transmit live surgery from the operating room to a handheld computer. This study establishes the feasibility of using our system to view surgeries and describes the effect of bandwidth on image quality. A live laparoscopic ventral hernia repair was transmitted to a single handheld computer using five encoding speeds at a constant frame rate, and the quality of the resulting streaming images was evaluated. No video images were rendered when video data were encoded at 28.8 kilobytes per second (Kbps), the slowest encoding bitrate studied. The highest quality images were rendered at encoding speeds greater than or equal to 150 Kbps. Of note, a 15 second transmission delay was experienced using all four encoding schemes that rendered video images. We believe that the wireless transmission of streaming video to handheld computers has tremendous potential to enhance surgical education. For medical students and residents, the ability to view live surgeries, lectures, courses and seminars on handheld computers means a larger number of learning opportunities. In addition, we envision that wireless enabled devices may be used to telemonitor surgical procedures. However, bandwidth availability and streaming delay are major issues that must be addressed before wireless telementoring becomes a reality.
Knösel, M; Engelke, W; Helms, H-J; Bleckmann, A
2012-08-01
To systematically assess the informational value, quality, intention, source and bias of web 2.0 footage whose aim is peer-to-peer education about oral implantology. YouTube (http://www.youtube.com) was scanned on 15 October 2010 for oral implantology-related videos using an adequately pre-defined search query. Search results were filtered with the system-generated category 'education' and the additional criterion 'most viewed'. Only those videos with at least 1000 views were included (total 124, of which 27 were excluded because they were not related to implantology). Filtered videos were discussed and rated with particular regard to the educational needs of potential groups of addressees [(i) undergraduates and laymen, (ii) dentists without or currently undergoing a specialisation in oral implantology and (iii) dentists who have completed a specialisation in the field of oral implantology] by a jury consisting of (i) an accredited post-graduate university instructor with 22 years of professional teaching experience in the field of implantology, (ii) a university lecturer in dentistry/orthodontics with 10 years teaching experience and (iii) a university haematologist/oncologist. They were required to fill out a questionnaire for each video. The data were statistically analysed using non-parametric ANOVA (α = 5%) and a sign test (α = 0.05/3 = 0.017). The YouTube scan produced 1710 results in the category 'EDU'. The analysis revealed that there is a wide range of instructional footage on this topic, but with highly variable range in quality and informational value. Footage intention was to large proportions (47.4%) a mixture of education and advertisement. Its usefulness differed significantly for the three groups of addressees, offering greater novelty to undergraduates and post-graduates. YouTube and similar social media websites may have a potential capacity and value in complementing continuing education in the technique of oral implantology. As a means of achieving an acceptable level of knowledge about the topic when used alone, it should not be considered to be suitable at this point in time. © 2012 John Wiley & Sons A/S.
Influence of video compression on the measurement error of the television system
NASA Astrophysics Data System (ADS)
Sotnik, A. V.; Yarishev, S. N.; Korotaev, V. V.
2015-05-01
Video data require a very large memory capacity. Optimal ratio quality / volume video encoding method is one of the most actual problem due to the urgent need to transfer large amounts of video over various networks. The technology of digital TV signal compression reduces the amount of data used for video stream representation. Video compression allows effective reduce the stream required for transmission and storage. It is important to take into account the uncertainties caused by compression of the video signal in the case of television measuring systems using. There are a lot digital compression methods. The aim of proposed work is research of video compression influence on the measurement error in television systems. Measurement error of the object parameter is the main characteristic of television measuring systems. Accuracy characterizes the difference between the measured value abd the actual parameter value. Errors caused by the optical system can be selected as a source of error in the television systems measurements. Method of the received video signal processing is also a source of error. Presence of error leads to large distortions in case of compression with constant data stream rate. Presence of errors increases the amount of data required to transmit or record an image frame in case of constant quality. The purpose of the intra-coding is reducing of the spatial redundancy within a frame (or field) of television image. This redundancy caused by the strong correlation between the elements of the image. It is possible to convert an array of image samples into a matrix of coefficients that are not correlated with each other, if one can find corresponding orthogonal transformation. It is possible to apply entropy coding to these uncorrelated coefficients and achieve a reduction in the digital stream. One can select such transformation that most of the matrix coefficients will be almost zero for typical images . Excluding these zero coefficients also possible reducing of the digital stream. Discrete cosine transformation is most widely used among possible orthogonal transformation. Errors of television measuring systems and data compression protocols analyzed In this paper. The main characteristics of measuring systems and detected sources of their error detected. The most effective methods of video compression are determined. The influence of video compression error on television measuring systems was researched. Obtained results will increase the accuracy of the measuring systems. In television image quality measuring system reduces distortion identical distortion in analog systems and specific distortions resulting from the process of coding / decoding digital video signal and errors in the transmission channel. By the distortions associated with encoding / decoding signal include quantization noise, reducing resolution, mosaic effect, "mosquito" effect edging on sharp drops brightness, blur colors, false patterns, the effect of "dirty window" and other defects. The size of video compression algorithms used in television measuring systems based on the image encoding with intra- and inter prediction individual fragments. The process of encoding / decoding image is non-linear in space and in time, because the quality of the playback of a movie at the reception depends on the pre- and post-history of a random, from the preceding and succeeding tracks, which can lead to distortion of the inadequacy of the sub-picture and a corresponding measuring signal.
Multilevel wireless capsule endoscopy video segmentation
NASA Astrophysics Data System (ADS)
Hwang, Sae; Celebi, M. Emre
2010-03-01
Wireless Capsule Endoscopy (WCE) is a relatively new technology (FDA approved in 2002) allowing doctors to view most of the small intestine. WCE transmits more than 50,000 video frames per examination and the visual inspection of the resulting video is a highly time-consuming task even for the experienced gastroenterologist. Typically, a medical clinician spends one or two hours to analyze a WCE video. To reduce the assessment time, it is critical to develop a technique to automatically discriminate digestive organs and shots each of which consists of the same or similar shots. In this paper a multi-level WCE video segmentation methodology is presented to reduce the examination time.
Video Guidance, Landing, and Imaging system (VGLIS) for space missions
NASA Technical Reports Server (NTRS)
Schappell, R. T.; Knickerbocker, R. L.; Tietz, J. C.; Grant, C.; Flemming, J. C.
1975-01-01
The feasibility of an autonomous video guidance system that is capable of observing a planetary surface during terminal descent and selecting the most acceptable landing site was demonstrated. The system was breadboarded and "flown" on a physical simulator consisting of a control panel and monitor, a dynamic simulator, and a PDP-9 computer. The breadboard VGLIS consisted of an image dissector camera and the appropriate processing logic. Results are reported.
Virtual viewpoint synthesis in multi-view video system
NASA Astrophysics Data System (ADS)
Li, Fang; Yang, Shiqiang
2005-07-01
In this paper, we present a virtual viewpoint video synthesis algorithm to satisfy the following three aims: low computing consuming; real time interpolation and acceptable video quality. In contrast with previous technologies, this method obtain incompletely 3D structure using neighbor video sources instead of getting total 3D information with all video sources, so that the computation is reduced greatly. So we demonstrate our interactive multi-view video synthesis algorithm in a personal computer. Furthermore, adopting the method of choosing feature points to build the correspondence between the frames captured by neighbor cameras, we need not require camera calibration. Finally, our method can be used when the angle between neighbor cameras is 25-30 degrees that it is much larger than common computer vision experiments. In this way, our method can be applied into many applications such as sports live, video conference, etc.
A novel Kalman filter based video image processing scheme for two-photon fluorescence microscopy
NASA Astrophysics Data System (ADS)
Sun, Wenqing; Huang, Xia; Li, Chunqiang; Xiao, Chuan; Qian, Wei
2016-03-01
Two-photon fluorescence microscopy (TPFM) is a perfect optical imaging equipment to monitor the interaction between fast moving viruses and hosts. However, due to strong unavoidable background noises from the culture, videos obtained by this technique are too noisy to elaborate this fast infection process without video image processing. In this study, we developed a novel scheme to eliminate background noises, recover background bacteria images and improve video qualities. In our scheme, we modified and implemented the following methods for both host and virus videos: correlation method, round identification method, tree-structured nonlinear filters, Kalman filters, and cell tracking method. After these procedures, most of noises were eliminated and host images were recovered with their moving directions and speed highlighted in the videos. From the analysis of the processed videos, 93% bacteria and 98% viruses were correctly detected in each frame on average.
Interactive Video: Meeting the Ford Challenge.
ERIC Educational Resources Information Center
Copeland, Peter
Many companies using Statistical Process Control (SPC) in their manufacturing processes have found that, despite the training difficulties presented by the technique, the rewards of successful SPC include increased productivity, quality, and market leadership. The Ford Motor Company has developed its SPC training with interactive video, which…
47 CFR 76.60 - Compensation for carriage.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 47 Telecommunication 4 2012-10-01 2012-10-01 false Compensation for carriage. 76.60 Section 76.60 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND... bear the costs associated with delivering a good quality signal or a baseband video signal to the...
47 CFR 76.60 - Compensation for carriage.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 47 Telecommunication 4 2014-10-01 2014-10-01 false Compensation for carriage. 76.60 Section 76.60 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND... bear the costs associated with delivering a good quality signal or a baseband video signal to the...
47 CFR 76.60 - Compensation for carriage.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 47 Telecommunication 4 2013-10-01 2013-10-01 false Compensation for carriage. 76.60 Section 76.60 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND... bear the costs associated with delivering a good quality signal or a baseband video signal to the...
47 CFR 76.60 - Compensation for carriage.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 47 Telecommunication 4 2011-10-01 2011-10-01 false Compensation for carriage. 76.60 Section 76.60 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND... bear the costs associated with delivering a good quality signal or a baseband video signal to the...
Social media: physicians-to-physicians education and communication.
Fehring, Keith A; De Martino, Ivan; McLawhorn, Alexander S; Sculco, Peter K
2017-06-01
Physician to physician communication is essential for the transfer of ideas, surgical experience, and education. Social networks and online video educational contents have grown exponentially in recent years changing the interaction among physicians. Social media platforms can improve physician-to-physician communication mostly through video education and social networking. There are several online video platforms for orthopedic surgery with educational content on diagnosis, treatment, outcomes, and surgical technique. Social networking instead is mostly centered on sharing of data, discussion of confidential topics, and job seeking. Quality of educational contents and data confidentiality represent the major drawbacks of these platforms. Orthopedic surgeons must be aware that the quality of the videos should be better controlled and regulated to avoid inaccurate information that may have a significant impact especially on trainees that are more prone to use this type of resources. Sharing of data and discussion of confidential topics should be extremely secure according the HIPAA regulations in order to protect patients' confidentiality.
A real-time inverse quantised transform for multi-standard with dynamic resolution support
NASA Astrophysics Data System (ADS)
Sun, Chi-Chia; Lin, Chun-Ying; Zhang, Ce
2016-06-01
In this paper, a real-time configurable intelligent property (IP) core is presented for image/video decoding process in compatibility with the standard MPEG-4 Visual and the standard H.264/AVC. The inverse quantised discrete cosine and integer transform can be used to perform inverse quantised discrete cosine transform and inverse quantised inverse integer transforms which only required shift and add operations. Meanwhile, COordinate Rotation DIgital Computer iterations and compensation steps are adjustable in order to compensate for the video compression quality regarding various data throughput. The implementations are embedded in publicly available software XVID Codes 1.2.2 for the standard MPEG-4 Visual and the H.264/AVC reference software JM 16.1, where the experimental results show that the balance between the computational complexity and video compression quality is retained. At the end, FPGA synthesised results show that the proposed IP core can bring advantages to low hardware costs and also provide real-time performance for Full HD and 4K-2K video decoding.
Lim, Tae Ho; Choi, Hyuk Joong; Kang, Bo Seung
2010-01-01
We assessed the feasibility of using a camcorder mobile phone for teleconsulting about cardiac echocardiography. The diagnostic performance of evaluating left ventricle (LV) systolic function was measured by three emergency medicine physicians. A total of 138 short echocardiography video sequences (from 70 subjects) was selected from previous emergency room ultrasound examinations. The measurement of LV ejection fraction based on the transmitted video displayed on a mobile phone was compared with the original video displayed on the LCD monitor of the ultrasound machine. The image quality was evaluated using the double stimulation impairment scale (DSIS). All observers showed high sensitivity. There was an improvement in specificity with the observer's increasing experience of cardiac ultrasound. Although the image quality of video on the mobile phone was lower than that of the original, a receiver operating characteristic (ROC) analysis indicated that there was no significant difference in diagnostic performance. Immediate basic teleconsulting of echocardiography movies is possible using current commercially-available mobile phone systems.
How social media meet patients questions: YouTube review for children oral thrush.
Di Stasio, D; Romano, A N; Paparella, R S; Gentile, C; Minervini, G; Serpico, R; Candotto, V; Laino, L
2018-01-01
YouTube is increasingly being used by patients to obtain health-related information. No studies have evaluated the content of YouTube videos on children oral thrush. The aim of this work is to examine the quality of information offered by this platform about oral thrush in children. Searching term oral thrush in children (OTC) displayed a total of 2.790 results. Of the top 60 videos analyzed, 27 were excluded. The main source of upload was from generalist information YouTube® channels (GC) followed by healthcare professionals (HP), individual users (IU), and healthcare information channels (HC); usefulness of videos is successfully correlated with the number of visualization, number of likes and viewing rate and was interdependent with the number of visualizations, number of likes and VR. However, videos on the oral thrush do not have satisfactory quality information. HP themselves, along with HC, do not seem to provide more appropriate information on COT, than GC or IU.
Video coding for next-generation surveillance systems
NASA Astrophysics Data System (ADS)
Klasen, Lena M.; Fahlander, Olov
1997-02-01
Video is used as recording media in surveillance system and also more frequently by the Swedish Police Force. Methods for analyzing video using an image processing system have recently been introduced at the Swedish National Laboratory of Forensic Science, and new methods are in focus in a research project at Linkoping University, Image Coding Group. The accuracy of the result of those forensic investigations often depends on the quality of the video recordings, and one of the major problems when analyzing videos from crime scenes is the poor quality of the recordings. Enhancing poor image quality might add manipulative or subjective effects and does not seem to be the right way of getting reliable analysis results. The surveillance system in use today is mainly based on video techniques, VHS or S-VHS, and the weakest link is the video cassette recorder, (VCR). Multiplexers for selecting one of many camera outputs for recording is another problem as it often filters the video signal, and recording is limited to only one of the available cameras connected to the VCR. A way to get around the problem of poor recording is to simultaneously record all camera outputs digitally. It is also very important to build such a system bearing in mind that image processing analysis methods becomes more important as a complement to the human eye. Using one or more cameras gives a large amount of data, and the need for data compression is more than obvious. Crime scenes often involve persons or moving objects, and the available coding techniques are more or less useful. Our goal is to propose a possible system, being the best compromise with respect to what needs to be recorded, movements in the recorded scene, loss of information and resolution etc., to secure the efficient recording of the crime and enable forensic analysis. The preventative effective of having a well functioning surveillance system and well established image analysis methods is not to be neglected. Aspects of this next generation of digital surveillance systems are discussed in this paper.
Delta L: An Apparatus for Measuring Macromolecule Crystal Growth Rates in Microgravity
NASA Technical Reports Server (NTRS)
Judge, Russell A.; Whitaker, Ann F. (Technical Monitor)
2001-01-01
Strongly diffracting high quality macromolecule crystals of suitable volume are keenly sought for X-ray diffraction analysis so that high-resolution molecular structure data can be obtained. Such data is of tremendous value to medical research, agriculture and commercial biotechnology. In previous studies by many investigators microgravity has been reported in some instances to improve biological macromolecule X-ray crystal quality while little or no improvement was observed in other cases. A better understanding of processes effecting crystal quality improvement in microgravity will therefore be of great benefit in optimizing crystallization success in microgravity. In ground based research with the protein lysozyme we have previously shown that a population of crystals grown under the same solution conditions, exhibit a variation in X-ray diffraction properties (Judge et al., 1999). We have also observed that under the same solution conditions, individual crystals will grow at slightly different growth rates. This phenomenon is called growth rate dispersion. For small molecule materials growth rate dispersion has been directly related to crystal quality (Cunningham et al., 1991; Ristic et al., 1991). We therefore postulate that microgravity may act to improve crystal quality by reducing growth rate dispersion. If this is the case then as different, Materials exhibit different degrees of growth rate dispersion on the ground then growth rate dispersion could be used to screen which materials may benefit the most from microgravity crystallization. In order to assess this theory the Delta L hardware is being developed so that macromolecule crystal growth rates can be measured in microgravity. Crystal growth rate is defined as the change or delta in crystal size (defined as a characteristic length, L) over time; hence the name of the hardware. Delta L will consist of an optics, a fluids, and a data acquisition sub-assemblies. The optics assembly will consist of a video microscope camera mounted on three axis computer controlled translation stages. The fluids assembly consists of macromolecule and precipitant reservoirs, a temperature controlled growth cell and waste container, The data acquisition is achieved by using a frame-gabber, with images being stored on a hard drive. In operation, macromolecule and precipitant solution will be injected into the temperature controlled growth cell. As macromolecule crystals grow, the video microscope camera controlled by the translation stages, will be used to locate and record images of individual crystals, returning to the same crystals at specific time intervals. The images will be stored on the hard drive and used to calculate the crystal growth rate. To prevent vibrations interfering in the crystal growth rate measurements (Snell et al., 1997) Delta L will be used in connection with the Glovebox Integrated Microgravity Isolation Technology (g-LIMIT) inside the Microgravity Science Glovebox (MSG), onboard the International Space Station (ISS).
1999-06-01
Two scientists at NASA's Marshall Space Flight Center,atmospheric scientist Paul Meyer and solar physicist Dr. David Hathaway, developed promising new software, called Video Image Stabilization and Registration (VISAR). VISAR may help law enforcement agencies catch criminals by improving the quality of video recorded at crime scenes. In this photograph, the single frame at left, taken at night, was brightened in order to enhance details and reduce noise or snow. To further overcome the video defects in one frame, Law enforcement officials can use VISAR software to add information from multiple frames to reveal a person. Images from less than a second of videotape were added together to create the clarified image at right. VISAR stabilizes camera motion in the horizontal and vertical as well as rotation and zoom effects producing clearer images of moving objects, smoothes jagged edges, enhances still images, and reduces video noise or snow. VISAR could also have applications in medical and meteorological imaging. It could steady images of ultrasounds, which are infamous for their grainy, blurred quality. The software can be used for defense application by improving recornaissance video imagery made by military vehicles, aircraft, and ships traveling in harsh, rugged environments.
Remote driving with reduced bandwidth communication
NASA Technical Reports Server (NTRS)
Depiero, Frederick W.; Noell, Timothy E.; Gee, Timothy F.
1993-01-01
Oak Ridge National Laboratory has developed a real-time video transmission system for low bandwidth remote operations. The system supports both continuous transmission of video for remote driving and progressive transmission of still images. Inherent in the system design is a spatiotemporal limitation to the effects of channel errors. The average data rate of the system is 64,000 bits/s, a compression of approximately 1000:1 for the black and white National Television Standard Code video. The image quality of the transmissions is maintained at a level that supports teleoperation of a high mobility multipurpose wheeled vehicle at speeds up to 15 mph on a moguled dirt track. Video compression is achieved by using Laplacian image pyramids and a combination of classical techniques. Certain subbands of the image pyramid are transmitted by using interframe differencing with a periodic refresh to aid in bandwidth reduction. Images are also foveated to concentrate image detail in a steerable region. The system supports dynamic video quality adjustments between frame rate, image detail, and foveation rate. A typical configuration for the system used during driving has a frame rate of 4 Hz, a compression per frame of 125:1, and a resulting latency of less than 1s.