A Near-Optimal Distributed QoS Constrained Routing Algorithm for Multichannel Wireless Sensor Networks

PubMed Central

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.

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.

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.

A new metric to assess temporal coherence for video retargeting

NASA Astrophysics Data System (ADS)

Li, Ke; Yan, Bo; Yuan, Binhang

2014-10-01

In video retargeting, how to assess the performance in maintaining temporal coherence has become the prominent challenge. In this paper, we will present a new objective measurement to assess temporal coherence after video retargeting. It's a general metric to assess jittery artifact for both discrete and continuous video retargeting methods, the accuracy of which is verified by psycho-visual tests. As a result, our proposed assessment method possesses huge practical significance.

No-Reference Video Quality Assessment Based on Statistical Analysis in 3D-DCT Domain.

PubMed

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.

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.

A no-reference bitstream-based perceptual model for video quality estimation of videos affected by coding artifacts and packet losses

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.

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.

"They may be pixels, but they're MY pixels:" developing a metric of character attachment in role-playing video games.

PubMed

Lewis, Melissa L; Weber, René; Bowman, Nicholas David

2008-08-01

This paper proposes a new and reliable metric for measuring character attachment (CA), the connection felt by a video game player toward a video game character. Results of construct validity analyses indicate that the proposed CA scale has a significant relationship with self-esteem, addiction, game enjoyment, and time spent playing games; all of these relationships are predicted by theory. Additionally, CA levels for role-playing games differ significantly from CA levels of other character-driven games.

Role of quality of service metrics in visual target acquisition and tracking in resource constrained environments

NASA Astrophysics Data System (ADS)

Anderson, Monica; David, Phillip

2007-04-01

Implementation of an intelligent, automated target acquisition and tracking systems alleviates the need for operators to monitor video continuously. This system could identify situations that fatigued operators could easily miss. If an automated acquisition and tracking system plans motions to maximize a coverage metric, how does the performance of that system change when the user intervenes and manually moves the camera? How can the operator give input to the system about what is important and understand how that relates to the overall task balance between surveillance and coverage? In this paper, we address these issues by introducing a new formulation of the average linear uncovered length (ALUL) metric, specially designed for use in surveilling urban environments. This metric coordinates the often competing goals of acquiring new targets and tracking existing targets. In addition, it provides current system performance feedback to system users in terms of the system's theoretical maximum and minimum performance. We show the successful integration of the algorithm via simulation.

Video redaction: a survey and comparison of enabling technologies

NASA Astrophysics Data System (ADS)

Sah, Shagan; Shringi, Ameya; Ptucha, Raymond; Burry, Aaron; Loce, Robert

2017-09-01

With the prevalence of video recordings from smart phones, dash cams, body cams, and conventional surveillance cameras, privacy protection has become a major concern, especially in light of legislation such as the Freedom of Information Act. Video redaction is used to obfuscate sensitive and personally identifiable information. Today's typical workflow involves simple detection, tracking, and manual intervention. Automated methods rely on accurate detection mechanisms being paired with robust tracking methods across the video sequence to ensure the redaction of all sensitive information while minimizing spurious obfuscations. Recent studies have explored the use of convolution neural networks and recurrent neural networks for object detection and tracking. The present paper reviews the redaction problem and compares a few state-of-the-art detection, tracking, and obfuscation methods as they relate to redaction. The comparison introduces an evaluation metric that is specific to video redaction performance. The metric can be evaluated in a manner that allows balancing the penalty for false negatives and false positives according to the needs of particular application, thereby assisting in the selection of component methods and their associated hyperparameters such that the redacted video has fewer frames that require manual review.

Image and Video Quality Assessment Using LCD: Comparisons with CRT Conditions

NASA Astrophysics Data System (ADS)

Tourancheau, Sylvain; Callet, Patrick Le; Barba, Dominique

In this paper, the impact of display on quality assessment is addressed. Subjective quality assessment experiments have been performed on both LCD and CRT displays. Two sets of still images and two sets of moving pictures have been assessed using either an ACR or a SAMVIQ protocol. Altogether, eight experiments have been led. Results are presented and discussed, some differences are pointed out. Concerning moving pictures, these differences seem to be mainly due to LCD moving artefacts such as motion blur. LCD motion blur has been measured objectively and with psycho-physics experiments. A motion-blur metric based on the temporal characteristics of LCD can be defined. A prediction model have been then designed which predict the differences of perceived quality between CRT and LCD. This motion-blur-based model enables the estimation of perceived quality on LCD with respect to the perceived quality on CRT. Technical solutions to LCD motion blur can thus be evaluated on natural contents by this mean.

HealthTrust: A Social Network Approach for Retrieving Online Health Videos

PubMed Central

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

HealthTrust: a social network approach for retrieving online health videos.

PubMed

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.

Noise Estimation and Quality Assessment of Gaussian Noise Corrupted Images

NASA Astrophysics Data System (ADS)

Kamble, V. M.; Bhurchandi, K.

2018-03-01

Evaluating the exact quantity of noise present in an image and quality of an image in the absence of reference image is a challenging task. We propose a near perfect noise estimation method and a no reference image quality assessment method for images corrupted by Gaussian noise. The proposed methods obtain initial estimate of noise standard deviation present in an image using the median of wavelet transform coefficients and then obtains a near to exact estimate using curve fitting. The proposed noise estimation method provides the estimate of noise within average error of +/-4%. For quality assessment, this noise estimate is mapped to fit the Differential Mean Opinion Score (DMOS) using a nonlinear function. The proposed methods require minimum training and yields the noise estimate and image quality score. Images from Laboratory for image and Video Processing (LIVE) database and Computational Perception and Image Quality (CSIQ) database are used for validation of the proposed quality assessment method. Experimental results show that the performance of proposed quality assessment method is at par with the existing no reference image quality assessment metric for Gaussian noise corrupted images.

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.

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.

Application of Sigma Metrics Analysis for the Assessment and Modification of Quality Control Program in the Clinical Chemistry Laboratory of a Tertiary Care Hospital.

PubMed

Iqbal, Sahar; Mustansar, Tazeen

2017-03-01

Sigma is a metric that quantifies the performance of a process as a rate of Defects-Per-Million opportunities. In clinical laboratories, sigma metric analysis is used to assess the performance of laboratory process system. Sigma metric is also used as a quality management strategy for a laboratory process to improve the quality by addressing the errors after identification. The aim of this study is to evaluate the errors in quality control of analytical phase of laboratory system by sigma metric. For this purpose sigma metric analysis was done for analytes using the internal and external quality control as quality indicators. Results of sigma metric analysis were used to identify the gaps and need for modification in the strategy of laboratory quality control procedure. Sigma metric was calculated for quality control program of ten clinical chemistry analytes including glucose, chloride, cholesterol, triglyceride, HDL, albumin, direct bilirubin, total bilirubin, protein and creatinine, at two control levels. To calculate the sigma metric imprecision and bias was calculated with internal and external quality control data, respectively. The minimum acceptable performance was considered as 3 sigma. Westgard sigma rules were applied to customize the quality control procedure. Sigma level was found acceptable (≥3) for glucose (L2), cholesterol, triglyceride, HDL, direct bilirubin and creatinine at both levels of control. For rest of the analytes sigma metric was found <3. The lowest value for sigma was found for chloride (1.1) at L2. The highest value of sigma was found for creatinine (10.1) at L3. HDL was found with the highest sigma values at both control levels (8.8 and 8.0 at L2 and L3, respectively). We conclude that analytes with the sigma value <3 are required strict monitoring and modification in quality control procedure. In this study application of sigma rules provided us the practical solution for improved and focused design of QC procedure.

Adaptive metric learning with deep neural networks for video-based facial expression recognition

NASA Astrophysics Data System (ADS)

Liu, Xiaofeng; Ge, Yubin; Yang, Chao; Jia, Ping

2018-01-01

Video-based facial expression recognition has become increasingly important for plenty of applications in the real world. Despite that numerous efforts have been made for the single sequence, how to balance the complex distribution of intra- and interclass variations well between sequences has remained a great difficulty in this area. We propose the adaptive (N+M)-tuplet clusters loss function and optimize it with the softmax loss simultaneously in the training phrase. The variations introduced by personal attributes are alleviated using the similarity measurements of multiple samples in the feature space with many fewer comparison times as conventional deep metric learning approaches, which enables the metric calculations for large data applications (e.g., videos). Both the spatial and temporal relations are well explored by a unified framework that consists of an Inception-ResNet network with long short term memory and the two fully connected layer branches structure. Our proposed method has been evaluated with three well-known databases, and the experimental results show that our method outperforms many state-of-the-art approaches.

Music video shot segmentation using independent component analysis and keyframe extraction based on image complexity

NASA Astrophysics Data System (ADS)

Li, Wei; Chen, Ting; Zhang, Wenjun; Shi, Yunyu; Li, Jun

2012-04-01

In recent years, Music video data is increasing at an astonishing speed. Shot segmentation and keyframe extraction constitute a fundamental unit in organizing, indexing, retrieving video content. In this paper a unified framework is proposed to detect the shot boundaries and extract the keyframe of a shot. Music video is first segmented to shots by illumination-invariant chromaticity histogram in independent component (IC) analysis feature space .Then we presents a new metric, image complexity, to extract keyframe in a shot which is computed by ICs. Experimental results show the framework is effective and has a good performance.

Social image quality

NASA Astrophysics Data System (ADS)

Qiu, Guoping; Kheiri, Ahmed

2011-01-01

Current subjective image quality assessments have been developed in the laboratory environments, under controlledconditions, and are dependent on the participation of limited numbers of observers. In this research, with the help of Web 2.0 and social media technology, a new method for building a subjective image quality metric has been developed where the observers are the Internet users. A website with a simple user interface that enables Internet users from anywhere at any time to vote for a better quality version of a pair of the same image has been constructed. Users' votes are recorded and used to rank the images according to their perceived visual qualities. We have developed three rank aggregation algorithms to process the recorded pair comparison data, the first uses a naive approach, the second employs a Condorcet method, and the third uses the Dykstra's extension of Bradley-Terry method. The website has been collecting data for about three months and has accumulated over 10,000 votes at the time of writing this paper. Results show that the Internet and its allied technologies such as crowdsourcing offer a promising new paradigm for image and video quality assessment where hundreds of thousands of Internet users can contribute to building more robust image quality metrics. We have made Internet user generated social image quality (SIQ) data of a public image database available online (http://www.hdri.cs.nott.ac.uk/siq/) to provide the image quality research community with a new source of ground truth data. The website continues to collect votes and will include more public image databases and will also be extended to include videos to collect social video quality (SVQ) data. All data will be public available on the website in due course.

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.

Using animation quality metric to improve efficiency of global illumination computation for dynamic environments

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.

Consumer-based technology for distribution of surgical videos for objective evaluation.

PubMed

Gonzalez, Ray; Martinez, Jose M; Lo Menzo, Emanuele; Iglesias, Alberto R; Ro, Charles Y; Madan, Atul K

2012-08-01

The Global Operative Assessment of Laparoscopic Skill (GOALS) is one validated metric utilized to grade laparoscopic skills and has been utilized to score recorded operative videos. To facilitate easier viewing of these recorded videos, we are developing novel techniques to enable surgeons to view these videos. The objective of this study is to determine the feasibility of utilizing widespread current consumer-based technology to assist in distributing appropriate videos for objective evaluation. Videos from residents were recorded via a direct connection from the camera processor via an S-video output via a cable into a hub to connect to a standard laptop computer via a universal serial bus (USB) port. A standard consumer-based video editing program was utilized to capture the video and record in appropriate format. We utilized mp4 format, and depending on the size of the file, the videos were scaled down (compressed), their format changed (using a standard video editing program), or sliced into multiple videos. Standard available consumer-based programs were utilized to convert the video into a more appropriate format for handheld personal digital assistants. In addition, the videos were uploaded to a social networking website and video sharing websites. Recorded cases of laparoscopic cholecystectomy in a porcine model were utilized. Compression was required for all formats. All formats were accessed from home computers, work computers, and iPhones without difficulty. Qualitative analyses by four surgeons demonstrated appropriate quality to grade for these formats. Our preliminary results show promise that, utilizing consumer-based technology, videos can be easily distributed to surgeons to grade via GOALS via various methods. Easy accessibility may help make evaluation of resident videos less complicated and cumbersome.

A Novel Riemannian Metric Based on Riemannian Structure and Scaling Information for Fixed Low-Rank Matrix Completion.

PubMed

Mao, Shasha; Xiong, Lin; Jiao, Licheng; Feng, Tian; Yeung, Sai-Kit

2017-05-01

Riemannian optimization has been widely used to deal with the fixed low-rank matrix completion problem, and Riemannian metric is a crucial factor of obtaining the search direction in Riemannian optimization. This paper proposes a new Riemannian metric via simultaneously considering the Riemannian geometry structure and the scaling information, which is smoothly varying and invariant along the equivalence class. The proposed metric can make a tradeoff between the Riemannian geometry structure and the scaling information effectively. Essentially, it can be viewed as a generalization of some existing metrics. Based on the proposed Riemanian metric, we also design a Riemannian nonlinear conjugate gradient algorithm, which can efficiently solve the fixed low-rank matrix completion problem. By experimenting on the fixed low-rank matrix completion, collaborative filtering, and image and video recovery, it illustrates that the proposed method is superior to the state-of-the-art methods on the convergence efficiency and the numerical performance.

Memory colours and colour quality evaluation of conventional and solid-state lamps.

PubMed

Smet, Kevin A G; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

2010-12-06

A colour quality metric based on memory colours is presented. The basic idea is simple. The colour quality of a test source is evaluated as the degree of similarity between the colour appearance of a set of familiar objects and their memory colours. The closer the match, the better the colour quality. This similarity was quantified using a set of similarity distributions obtained by Smet et al. in a previous study. The metric was validated by calculating the Pearson and Spearman correlation coefficients between the metric predictions and the visual appreciation results obtained in a validation experiment conducted by the authors as well those obtained in two independent studies. The metric was found to correlate well with the visual appreciation of the lighting quality of the sources used in the three experiments. Its performance was also compared with that of the CIE colour rendering index and the NIST colour quality scale. For all three experiments, the metric was found to be significantly better at predicting the correct visual rank order of the light sources (p < 0.1).

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.

Quality of service routing in the differentiated services framework

NASA Astrophysics Data System (ADS)

Oliveira, Marilia C.; Melo, Bruno; Quadros, Goncalo; Monteiro, Edmundo

2001-02-01

In this paper we present a quality of service routing strategy for network where traffic differentiation follows the class-based paradigm, as in the Differentiated Services framework. This routing strategy is based on a metric of quality of service. This metric represents the impact that delay and losses verified at each router in the network have in application performance. Based on this metric, it is selected a path for each class according to the class sensitivity to delay and losses. The distribution of the metric is triggered by a relative criterion with two thresholds, and the values advertised are the moving average of the last values measured.

On mobile wireless ad hoc IP video transports

NASA Astrophysics Data System (ADS)

Kazantzidis, Matheos

2006-05-01

Multimedia transports in wireless, ad-hoc, multi-hop or mobile networks must be capable of obtaining information about the network and adaptively tune sending and encoding parameters to the network response. Obtaining meaningful metrics to guide a stable congestion control mechanism in the transport (i.e. passive, simple, end-to-end and network technology independent) is a complex problem. Equally difficult is obtaining a reliable QoS metrics that agrees with user perception in a client/server or distributed environment. Existing metrics, objective or subjective, are commonly used after or before to test or report on a transmission and require access to both original and transmitted frames. In this paper, we propose that an efficient and successful video delivery and the optimization of overall network QoS requires innovation in a) a direct measurement of available and bottleneck capacity for its congestion control and b) a meaningful subjective QoS metric that is dynamically reported to video sender. Once these are in place, a binomial -stable, fair and TCP friendly- algorithm can be used to determine the sending rate and other packet video parameters. An adaptive mpeg codec can then continually test and fit its parameters and temporal-spatial data-error control balance using the perceived QoS dynamic feedback. We suggest a new measurement based on a packet dispersion technique that is independent of underlying network mechanisms. We then present a binomial control based on direct measurements. We implement a QoS metric that is known to agree with user perception (MPQM) in a client/server, distributed environment by using predetermined table lookups and characterization of video content.

Ring-push metric learning for person reidentification

NASA Astrophysics Data System (ADS)

He, Botao; Yu, Shaohua

2017-05-01

Person reidentification (re-id) has been widely studied because of its extensive use in video surveillance and forensics applications. It aims to search a specific person among a nonoverlapping camera network, which is highly challenging due to large variations in the cluttered background, human pose, and camera viewpoint. We present a metric learning algorithm for learning a Mahalanobis distance for re-id. Generally speaking, there exist two forces in the conventional metric learning process, one pulling force that pulls points of the same class closer and the other pushing force that pushes points of different classes as far apart as possible. We argue that, when only a limited number of training data are given, forcing interclass distances to be as large as possible may drive the metric to overfit the uninformative part of the images, such as noises and backgrounds. To alleviate overfitting, we propose the ring-push metric learning algorithm. Different from other metric learning methods that only punish too small interclass distances, in the proposed method, both too small and too large inter-class distances are punished. By introducing the generalized logistic function as the loss, we formulate the ring-push metric learning as a convex optimization problem and utilize the projected gradient descent method to solve it. The experimental results on four public datasets demonstrate the effectiveness of the proposed algorithm.

An Optical Flow-Based Full Reference Video Quality Assessment Algorithm.

PubMed

K, Manasa; Channappayya, Sumohana S

2016-06-01

We present a simple yet effective optical flow-based full-reference video quality assessment (FR-VQA) algorithm for assessing the perceptual quality of natural videos. Our algorithm is based on the premise that local optical flow statistics are affected by distortions and the deviation from pristine flow statistics is proportional to the amount of distortion. We characterize the local flow statistics using the mean, the standard deviation, the coefficient of variation (CV), and the minimum eigenvalue ( λ min ) of the local flow patches. Temporal distortion is estimated as the change in the CV of the distorted flow with respect to the reference flow, and the correlation between λ min of the reference and of the distorted patches. We rely on the robust multi-scale structural similarity index for spatial quality estimation. The computed temporal and spatial distortions, thus, are then pooled using a perceptually motivated heuristic to generate a spatio-temporal quality score. The proposed method is shown to be competitive with the state-of-the-art when evaluated on the LIVE SD database, the EPFL Polimi SD database, and the LIVE Mobile HD database. The distortions considered in these databases include those due to compression, packet-loss, wireless channel errors, and rate-adaptation. Our algorithm is flexible enough to allow for any robust FR spatial distortion metric for spatial distortion estimation. In addition, the proposed method is not only parameter-free but also independent of the choice of the optical flow algorithm. Finally, we show that the replacement of the optical flow vectors in our proposed method with the much coarser block motion vectors also results in an acceptable FR-VQA algorithm. Our algorithm is called the flow similarity index.

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.

Validation of a Quality Management Metric

DTIC Science & Technology

2000-09-01

quality management metric (QMM) was used to measure the performance of ten software managers on Department of Defense (DoD) software development programs. Informal verification and validation of the metric compared the QMM score to an overall program success score for the entire program and yielded positive correlation. The results of applying the QMM can be used to characterize the quality of software management and can serve as a template to improve software management performance. Future work includes further refining the QMM, applying the QMM scores to provide feedback

Cultural Heritage Reconstruction from Historical Photographs and Videos

NASA Astrophysics Data System (ADS)

Condorelli, F.; Rinaudo, F.

2018-05-01

Historical archives save invaluable treasures and play a critical role in the conservation of Cultural Heritage. Old photographs and videos, which have survived over time and stored in these archives, preserve traces of architecture and urban transformation and, in many cases, are the only evidence of buildings that no longer exist. They are a precious source of enormous informative potential in Cultural Heritage documentation and save invaluable treasures. Thanks to photogrammetric techniques it is possible to extract metric information from these sources useful for 3D virtual reconstructions of monuments and historic buildings. This paper explores the ways to search for, classify and group historical data by considering their possible use in metric documentation and aims to provide an overview of criticality and open issues of the methodologies that could be used to process these data. A practical example is described and presented as a case study. The video "Torino 1928", an old movie dating from the 1930s, was processed for reconstructing the temporary pavilions of the "Exposition" held in Turin in 1928. Despite the initial concerns relating to processing this kind of data, the experimental methodology used in this research has allowed to reach a quality of results of acceptable standard.

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.

A condition metric for Eucalyptus woodland derived from expert evaluations.

PubMed

Sinclair, Steve J; Bruce, Matthew J; Griffioen, Peter; Dodd, Amanda; White, Matthew D

2018-02-01

The evaluation of ecosystem quality is important for land-management and land-use planning. Evaluation is unavoidably subjective, and robust metrics must be based on consensus and the structured use of observations. We devised a transparent and repeatable process for building and testing ecosystem metrics based on expert data. We gathered quantitative evaluation data on the quality of hypothetical grassy woodland sites from experts. We used these data to train a model (an ensemble of 30 bagged regression trees) capable of predicting the perceived quality of similar hypothetical woodlands based on a set of 13 site variables as inputs (e.g., cover of shrubs, richness of native forbs). These variables can be measured at any site and the model implemented in a spreadsheet as a metric of woodland quality. We also investigated the number of experts required to produce an opinion data set sufficient for the construction of a metric. The model produced evaluations similar to those provided by experts, as shown by assessing the model's quality scores of expert-evaluated test sites not used to train the model. We applied the metric to 13 woodland conservation reserves and asked managers of these sites to independently evaluate their quality. To assess metric performance, we compared the model's evaluation of site quality with the managers' evaluations through multidimensional scaling. The metric performed relatively well, plotting close to the center of the space defined by the evaluators. Given the method provides data-driven consensus and repeatability, which no single human evaluator can provide, we suggest it is a valuable tool for evaluating ecosystem quality in real-world contexts. We believe our approach is applicable to any ecosystem. © 2017 State of Victoria.

Surgical instrument similarity metrics and tray analysis for multi-sensor instrument identification

NASA Astrophysics Data System (ADS)

Glaser, Bernhard; Schellenberg, Tobias; Franke, Stefan; Dänzer, Stefan; Neumuth, Thomas

2015-03-01

A robust identification of the instrument currently used by the surgeon is crucial for the automatic modeling and analysis of surgical procedures. Various approaches for intra-operative surgical instrument identification have been presented, mostly based on radio-frequency identification (RFID) or endoscopic video analysis. A novel approach is to identify the instruments on the instrument table of the scrub nurse with a combination of video and weight information. In a previous article, we successfully followed this approach and applied it to multiple instances of an ear, nose and throat (ENT) procedure and the surgical tray used therein. In this article, we present a metric for the suitability of the instruments of a surgical tray for identification by video and weight analysis and apply it to twelve trays of four different surgical domains (abdominal surgery, neurosurgery, orthopedics and urology). The used trays were digitized at the central sterile services department of the hospital. The results illustrate that surgical trays differ in their suitability for the approach. In general, additional weight information can significantly contribute to the successful identification of surgical instruments. Additionally, for ten different surgical instruments, ten exemplars of each instrument were tested for their weight differences. The samples indicate high weight variability in instruments with identical brand and model number. The results present a new metric for approaches aiming towards intra-operative surgical instrument detection and imply consequences for algorithms exploiting video and weight information for identification purposes.

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."

Research and Technology Development for Construction of 3d Video Scenes

NASA Astrophysics Data System (ADS)

Khlebnikova, Tatyana A.

2016-06-01

For the last two decades surface information in the form of conventional digital and analogue topographic maps has been being supplemented by new digital geospatial products, also known as 3D models of real objects. It is shown that currently there are no defined standards for 3D scenes construction technologies that could be used by Russian surveying and cartographic enterprises. The issues regarding source data requirements, their capture and transferring to create 3D scenes have not been defined yet. The accuracy issues for 3D video scenes used for measuring purposes can hardly ever be found in publications. Practicability of development, research and implementation of technology for construction of 3D video scenes is substantiated by 3D video scene capability to expand the field of data analysis application for environmental monitoring, urban planning, and managerial decision problems. The technology for construction of 3D video scenes with regard to the specified metric requirements is offered. Technique and methodological background are recommended for this technology used to construct 3D video scenes based on DTM, which were created by satellite and aerial survey data. The results of accuracy estimation of 3D video scenes are presented.

Adaptive sigmoid function bihistogram equalization for image contrast enhancement

NASA Astrophysics Data System (ADS)

Arriaga-Garcia, Edgar F.; Sanchez-Yanez, Raul E.; Ruiz-Pinales, Jose; Garcia-Hernandez, Ma. de Guadalupe

2015-09-01

Contrast enhancement plays a key role in a wide range of applications including consumer electronic applications, such as video surveillance, digital cameras, and televisions. The main goal of contrast enhancement is to increase the quality of images. However, most state-of-the-art methods induce different types of distortion such as intensity shift, wash-out, noise, intensity burn-out, and intensity saturation. In addition, in consumer electronics, simple and fast methods are required in order to be implemented in real time. A bihistogram equalization method based on adaptive sigmoid functions is proposed. It consists of splitting the image histogram into two parts that are equalized independently by using adaptive sigmoid functions. In order to preserve the mean brightness of the input image, the parameter of the sigmoid functions is chosen to minimize the absolute mean brightness metric. Experiments on the Berkeley database have shown that the proposed method improves the quality of images and preserves their mean brightness. An application to improve the colorfulness of images is also presented.

The Endockscope Using Next Generation Smartphones: "A Global Opportunity".

PubMed

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).

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.

Video quality pooling adaptive to perceptual distortion severity.

PubMed

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.

Quality assessment for color reproduction using a blind metric

NASA Astrophysics Data System (ADS)

Bringier, B.; Quintard, L.; Larabi, M.-C.

2007-01-01

This paper deals with image quality assessment. This field plays nowadays an important role in various image processing applications. Number of objective image quality metrics, that correlate or not, with the subjective quality have been developed during the last decade. Two categories of metrics can be distinguished, the first with full-reference and the second with no-reference. Full-reference metric tries to evaluate the distortion introduced to an image with regards to the reference. No-reference approach attempts to model the judgment of image quality in a blind way. Unfortunately, the universal image quality model is not on the horizon and empirical models established on psychophysical experimentation are generally used. In this paper, we focus only on the second category to evaluate the quality of color reproduction where a blind metric, based on human visual system modeling is introduced. The objective results are validated by single-media and cross-media subjective tests.

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.

CVD2014-A Database for Evaluating No-Reference Video Quality Assessment Algorithms.

PubMed

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/).

Blind prediction of natural video quality.

PubMed

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.

Quality assessment of color images based on the measure of just noticeable color difference

NASA Astrophysics Data System (ADS)

Chou, Chun-Hsien; Hsu, Yun-Hsiang

2014-01-01

Accurate assessment on the quality of color images is an important step to many image processing systems that convey visual information of the reproduced images. An accurate objective image quality assessment (IQA) method is expected to give the assessment result highly agreeing with the subjective assessment. To assess the quality of color images, many approaches simply apply the metric for assessing the quality of gray scale images to each of three color channels of the color image, neglecting the correlation among three color channels. In this paper, a metric for assessing color images' quality is proposed, in which the model of variable just-noticeable color difference (VJNCD) is employed to estimate the visibility thresholds of distortion inherent in each color pixel. With the estimated visibility thresholds of distortion, the proposed metric measures the average perceptible distortion in terms of the quantized distortion according to the perceptual error map similar to that defined by National Bureau of Standards (NBS) for converting the color difference enumerated by CIEDE2000 to the objective score of perceptual quality assessment. The perceptual error map in this case is designed for each pixel according to the visibility threshold estimated by the VJNCD model. The performance of the proposed metric is verified by assessing the test images in the LIVE database, and is compared with those of many well-know IQA metrics. Experimental results indicate that the proposed metric is an effective IQA method that can accurately predict the image quality of color images in terms of the correlation between objective scores and subjective evaluation.

Large radius of curvature measurement based on the evaluation of interferogram-quality metric in non-null interferometry

NASA Astrophysics Data System (ADS)

Yang, Zhongming; Dou, Jiantai; Du, Jinyu; Gao, Zhishan

2018-03-01

Non-null interferometry could use to measure the radius of curvature (ROC), we have presented a virtual quadratic Newton rings phase-shifting moiré-fringes measurement method for large ROC measurement (Yang et al., 2016). In this paper, we propose a large ROC measurement method based on the evaluation of the interferogram-quality metric by the non-null interferometer. With the multi-configuration model of the non-null interferometric system in ZEMAX, the retrace errors and the phase introduced by the test surface are reconstructed. The interferogram-quality metric is obtained by the normalized phase-shifted testing Newton rings with the spherical surface model in the non-null interferometric system. The radius curvature of the test spherical surface can be obtained until the minimum of the interferogram-quality metric is found. Simulations and experimental results are verified the feasibility of our proposed method. For a spherical mirror with a ROC of 41,400 mm, the measurement accuracy is better than 0.13%.

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.

Spherical rotation orientation indication for HEVC and JEM coding of 360 degree video

NASA Astrophysics Data System (ADS)

Boyce, Jill; Xu, Qian

2017-09-01

Omnidirectional (or "360 degree") video, representing a panoramic view of a spherical 360° ×180° scene, can be encoded using conventional video compression standards, once it has been projection mapped to a 2D rectangular format. Equirectangular projection format is currently used for mapping 360 degree video to a rectangular representation for coding using HEVC/JEM. However, video in the top and bottom regions of the image, corresponding to the "north pole" and "south pole" of the spherical representation, is significantly warped. We propose to perform spherical rotation of the input video prior to HEVC/JEM encoding in order to improve the coding efficiency, and to signal parameters in a supplemental enhancement information (SEI) message that describe the inverse rotation process recommended to be applied following HEVC/JEM decoding, prior to display. Experiment results show that up to 17.8% bitrate gain (using the WS-PSNR end-to-end metric) can be achieved for the Chairlift sequence using HM16.15 and 11.9% gain using JEM6.0, and an average gain of 2.9% for HM16.15 and 2.2% for JEM6.0.

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.

Metrication report to the Congress. 1991 activities and 1992 plans

NASA Technical Reports Server (NTRS)

1991-01-01

During 1991, NASA approved a revised metric use policy and developed a NASA Metric Transition Plan. This Plan targets the end of 1995 for completion of NASA's metric initiatives. This Plan also identifies future programs that NASA anticipates will use the metric system of measurement. Field installations began metric transition studies in 1991 and will complete them in 1992. Half of NASA's Space Shuttle payloads for 1991, and almost all such payloads for 1992, have some metric-based elements. In 1992, NASA will begin assessing requirements for space-quality piece parts fabricated to U.S. metric standards, leading to development and qualification of high priority parts.

Video quality assessment using motion-compensated temporal filtering and manifold feature similarity

PubMed Central

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

Video quality assessment using a statistical model of human visual speed perception.

PubMed

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.

Perceived assessment metrics for visible and infrared color fused image quality without reference image

NASA Astrophysics Data System (ADS)

Yu, Xuelian; Chen, Qian; Gu, Guohua; Ren, Jianle; Sui, Xiubao

2015-02-01

Designing objective quality assessment of color-fused image is a very demanding and challenging task. We propose four no-reference metrics based on human visual system characteristics for objectively evaluating the quality of false color fusion image. The perceived edge metric (PEM) is defined based on visual perception model and color image gradient similarity between the fused image and the source images. The perceptual contrast metric (PCM) is established associating multi-scale contrast and varying contrast sensitivity filter (CSF) with color components. The linear combination of the standard deviation and mean value over the fused image construct the image colorfulness metric (ICM). The color comfort metric (CCM) is designed by the average saturation and the ratio of pixels with high and low saturation. The qualitative and quantitative experimental results demonstrate that the proposed metrics have a good agreement with subjective perception.

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.

Acquisition and Analysis of Dynamic Responses of a Historic Pedestrian Bridge using Video Image Processing

NASA Astrophysics Data System (ADS)

O'Byrne, Michael; Ghosh, Bidisha; Schoefs, Franck; O'Donnell, Deirdre; Wright, Robert; Pakrashi, Vikram

2015-07-01

Video based tracking is capable of analysing bridge vibrations that are characterised by large amplitudes and low frequencies. This paper presents the use of video images and associated image processing techniques to obtain the dynamic response of a pedestrian suspension bridge in Cork, Ireland. This historic structure is one of the four suspension bridges in Ireland and is notable for its dynamic nature. A video camera is mounted on the river-bank and the dynamic responses of the bridge have been measured from the video images. The dynamic response is assessed without the need of a reflector on the bridge and in the presence of various forms of luminous complexities in the video image scenes. Vertical deformations of the bridge were measured in this regard. The video image tracking for the measurement of dynamic responses of the bridge were based on correlating patches in time-lagged scenes in video images and utilisinga zero mean normalisedcross correlation (ZNCC) metric. The bridge was excited by designed pedestrian movement and by individual cyclists traversing the bridge. The time series data of dynamic displacement responses of the bridge were analysedto obtain the frequency domain response. Frequencies obtained from video analysis were checked against accelerometer data from the bridge obtained while carrying out the same set of experiments used for video image based recognition.

Encryption for confidentiality of the network and influence of this to the quality of streaming video through network

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.

Acquisition and Analysis of Dynamic Responses of a Historic Pedestrian Bridge using Video Image Processing

NASA Astrophysics Data System (ADS)

O'Byrne, Michael; Ghosh, Bidisha; Schoefs, Franck; O'Donnell, Deirdre; Wright, Robert; Pakrashi, Vikram

2015-07-01

Video based tracking is capable of analysing bridge vibrations that are characterised by large amplitudes and low frequencies. This paper presents the use of video images and associated image processing techniques to obtain the dynamic response of a pedestrian suspension bridge in Cork, Ireland. This historic structure is one of the four suspension bridges in Ireland and is notable for its dynamic nature. A video camera is mounted on the river-bank and the dynamic responses of the bridge have been measured from the video images. The dynamic response is assessed without the need of a reflector on the bridge and in the presence of various forms of luminous complexities in the video image scenes. Vertical deformations of the bridge were measured in this regard. The video image tracking for the measurement of dynamic responses of the bridge were based on correlating patches in time-lagged scenes in video images and utilisinga zero mean normalised cross correlation (ZNCC) metric. The bridge was excited by designed pedestrian movement and by individual cyclists traversing the bridge. The time series data of dynamic displacement responses of the bridge were analysedto obtain the frequency domain response. Frequencies obtained from video analysis were checked against accelerometer data from the bridge obtained while carrying out the same set of experiments used for video image based recognition.

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.

Toward objective image quality metrics: the AIC Eval Program of the JPEG

NASA Astrophysics Data System (ADS)

Richter, Thomas; Larabi, Chaker

2008-08-01

Objective quality assessment of lossy image compression codecs is an important part of the recent call of the JPEG for Advanced Image Coding. The target of the AIC ad-hoc group is twofold: First, to receive state-of-the-art still image codecs and to propose suitable technology for standardization; and second, to study objective image quality metrics to evaluate the performance of such codes. Even tthough the performance of an objective metric is defined by how well it predicts the outcome of a subjective assessment, one can also study the usefulness of a metric in a non-traditional way indirectly, namely by measuring the subjective quality improvement of a codec that has been optimized for a specific objective metric. This approach shall be demonstrated here on the recently proposed HDPhoto format14 introduced by Microsoft and a SSIM-tuned17 version of it by one of the authors. We compare these two implementations with JPEG1 in two variations and a visual and PSNR optimal JPEG200013 implementation. To this end, we use subjective and objective tests based on the multiscale SSIM and a new DCT based metric.

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.

Energy Efficient Image/Video Data Transmission on Commercial Multi-Core Processors

PubMed Central

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

Spread spectrum image watermarking based on perceptual quality metric.

PubMed

Zhang, Fan; Liu, Wenyu; Lin, Weisi; Ngan, King Ngi

2011-11-01

Efficient image watermarking calls for full exploitation of the perceptual distortion constraint. Second-order statistics of visual stimuli are regarded as critical features for perception. This paper proposes a second-order statistics (SOS)-based image quality metric, which considers the texture masking effect and the contrast sensitivity in Karhunen-Loève transform domain. Compared with the state-of-the-art metrics, the quality prediction by SOS better correlates with several subjectively rated image databases, in which the images are impaired by the typical coding and watermarking artifacts. With the explicit metric definition, spread spectrum watermarking is posed as an optimization problem: we search for a watermark to minimize the distortion of the watermarked image and to maximize the correlation between the watermark pattern and the spread spectrum carrier. The simple metric guarantees the optimal watermark a closed-form solution and a fast implementation. The experiments show that the proposed watermarking scheme can take full advantage of the distortion constraint and improve the robustness in return.

Qualitative and quantitative assessment of video transmitted by DVTS (digital video transport system) in surgical telemedicine.

PubMed

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.

Information fusion performance evaluation for motion imagery data using mutual information: initial study

NASA Astrophysics Data System (ADS)

Grieggs, Samuel M.; McLaughlin, Michael J.; Ezekiel, Soundararajan; Blasch, Erik

2015-06-01

As technology and internet use grows at an exponential rate, video and imagery data is becoming increasingly important. Various techniques such as Wide Area Motion imagery (WAMI), Full Motion Video (FMV), and Hyperspectral Imaging (HSI) are used to collect motion data and extract relevant information. Detecting and identifying a particular object in imagery data is an important step in understanding visual imagery, such as content-based image retrieval (CBIR). Imagery data is segmented and automatically analyzed and stored in dynamic and robust database. In our system, we seek utilize image fusion methods which require quality metrics. Many Image Fusion (IF) algorithms have been proposed based on different, but only a few metrics, used to evaluate the performance of these algorithms. In this paper, we seek a robust, objective metric to evaluate the performance of IF algorithms which compares the outcome of a given algorithm to ground truth and reports several types of errors. Given the ground truth of a motion imagery data, it will compute detection failure, false alarm, precision and recall metrics, background and foreground regions statistics, as well as split and merge of foreground regions. Using the Structural Similarity Index (SSIM), Mutual Information (MI), and entropy metrics; experimental results demonstrate the effectiveness of the proposed methodology for object detection, activity exploitation, and CBIR.

Video medical interpretation over 3G cellular networks: a feasibility study.

PubMed

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.

Reference View Selection in DIBR-Based Multiview Coding.

PubMed

Maugey, Thomas; Petrazzuoli, Giovanni; Frossard, Pascal; Cagnazzo, Marco; Pesquet-Popescu, Beatrice

2016-04-01

Augmented reality, interactive navigation in 3D scenes, multiview video, and other emerging multimedia applications require large sets of images, hence larger data volumes and increased resources compared with traditional video services. The significant increase in the number of images in multiview systems leads to new challenging problems in data representation and data transmission to provide high quality of experience on resource-constrained environments. In order to reduce the size of the data, different multiview video compression strategies have been proposed recently. Most of them use the concept of reference or key views that are used to estimate other images when there is high correlation in the data set. In such coding schemes, the two following questions become fundamental: 1) how many reference views have to be chosen for keeping a good reconstruction quality under coding cost constraints? And 2) where to place these key views in the multiview data set? As these questions are largely overlooked in the literature, we study the reference view selection problem and propose an algorithm for the optimal selection of reference views in multiview coding systems. Based on a novel metric that measures the similarity between the views, we formulate an optimization problem for the positioning of the reference views, such that both the distortion of the view reconstruction and the coding rate cost are minimized. We solve this new problem with a shortest path algorithm that determines both the optimal number of reference views and their positions in the image set. We experimentally validate our solution in a practical multiview distributed coding system and in the standardized 3D-HEVC multiview coding scheme. We show that considering the 3D scene geometry in the reference view, positioning problem brings significant rate-distortion improvements and outperforms the traditional coding strategy that simply selects key frames based on the distance between cameras.

Metric-driven harm: an exploration of unintended consequences of performance measurement.

PubMed

Rambur, Betty; Vallett, Carol; Cohen, Judith A; Tarule, Jill Mattuck

2013-11-01

Performance measurement is an increasingly common element of the US health care system. Typically a proxy for high quality outcomes, there has been little systematic investigation of the potential negative unintended consequences of performance metrics, including metric-driven harm. This case study details an incidence of post-surgical metric-driven harm and offers Smith's 1995 work and a patient centered, context sensitive metric model for potential adoption by nurse researchers and clinicians. Implications for further research are discussed. © 2013.

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.

Image quality assessment metric for frame accumulated image

NASA Astrophysics Data System (ADS)

Yu, Jianping; Li, Gang; Wang, Shaohui; Lin, Ling

2018-01-01

The medical image quality determines the accuracy of diagnosis, and the gray-scale resolution is an important parameter to measure image quality. But current objective metrics are not very suitable for assessing medical images obtained by frame accumulation technology. Little attention was paid to the gray-scale resolution, basically based on spatial resolution and limited to the 256 level gray scale of the existing display device. Thus, this paper proposes a metric, "mean signal-to-noise ratio" (MSNR) based on signal-to-noise in order to be more reasonable to evaluate frame accumulated medical image quality. We demonstrate its potential application through a series of images under a constant illumination signal. Here, the mean image of enough images was regarded as the reference image. Several groups of images by different frame accumulation and their MSNR were calculated. The results of the experiment show that, compared with other quality assessment methods, the metric is simpler, more effective, and more suitable for assessing frame accumulated images that surpass the gray scale and precision of the original image.

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.

Imagining life with an ostomy: Does a video intervention improve quality-of-life predictions for a medical condition that may elicit disgust?☆

PubMed Central

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

46 CFR 298.11 - Vessel requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... with accepted commercial experience and practice. (g) Metric Usage. Our preferred system of measurement and weights for Vessels and Shipyard Projects is the metric system. ...), classification societies to be ISO 9000 series registered or Quality Systems Certificate Scheme qualified IACS...

46 CFR 298.11 - Vessel requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... with accepted commercial experience and practice. (g) Metric Usage. Our preferred system of measurement and weights for Vessels and Shipyard Projects is the metric system. ...), classification societies to be ISO 9000 series registered or Quality Systems Certificate Scheme qualified IACS...

46 CFR 298.11 - Vessel requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... with accepted commercial experience and practice. (g) Metric Usage. Our preferred system of measurement and weights for Vessels and Shipyard Projects is the metric system. ...), classification societies to be ISO 9000 series registered or Quality Systems Certificate Scheme qualified IACS...

46 CFR 298.11 - Vessel requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... with accepted commercial experience and practice. (g) Metric Usage. Our preferred system of measurement and weights for Vessels and Shipyard Projects is the metric system. ...), classification societies to be ISO 9000 series registered or Quality Systems Certificate Scheme qualified IACS...

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.

46 CFR 298.11 - Vessel requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... with accepted commercial experience and practice. (g) Metric Usage. Our preferred system of measurement and weights for Vessels and Shipyard Projects is the metric system. ...), classification societies to be ISO 9000 series registered or Quality Systems Certificate Scheme qualified IACS...

Engagement with electronic screen media among students with autism spectrum disorders.

PubMed

Mineo, Beth A; Ziegler, William; Gill, Susan; Salkin, Donna

2009-01-01

This study investigated the relative engagement potential of four types of electronic screen media (ESM): animated video, video of self, video of a familiar person engaged with an immersive virtual reality (VR) game, and immersion of self in the VR game. Forty-two students with autism, varying in age and expressive communication ability, were randomly assigned to the experimental conditions. Gaze duration and vocalization served as dependent measures of engagement. The results reveal differential responding across ESM, with some variation related to the engagement metric employed. Preferences for seeing themselves on the screen, as well as for viewing the VR scenarios, emerged from the data. While the study did not yield definitive data about the relative engagement potential of ESM alternatives, it does provide a foundation for future research, including guidance related to participant profiles, stimulus characteristics, and data coding challenges.

Enhanced video indirect ophthalmoscopy (VIO) via robust mosaicing.

PubMed

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.

A randomized controlled trial of an educational video to improve quality of bowel preparation for colonoscopy.

PubMed

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.

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.

Portable color multimedia training systems based on monochrome laptop computers (CBT-in-a-briefcase), with spinoff implications for video uplink and downlink in spaceflight operations

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.

An Energy-Efficient and High-Quality Video Transmission Architecture in Wireless Video-Based Sensor Networks.

PubMed

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.

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.

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.

Video on Diet Before Outpatient Colonoscopy Does Not Improve Quality of Bowel Preparation: A Prospective, Randomized, Controlled Trial.

PubMed

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.

A probability metric for identifying high-performing facilities: an application for pay-for-performance programs.

PubMed

Shwartz, Michael; Peköz, Erol A; Burgess, James F; Christiansen, Cindy L; Rosen, Amy K; Berlowitz, Dan

2014-12-01

Two approaches are commonly used for identifying high-performing facilities on a performance measure: one, that the facility is in a top quantile (eg, quintile or quartile); and two, that a confidence interval is below (or above) the average of the measure for all facilities. This type of yes/no designation often does not do well in distinguishing high-performing from average-performing facilities. To illustrate an alternative continuous-valued metric for profiling facilities--the probability a facility is in a top quantile--and show the implications of using this metric for profiling and pay-for-performance. We created a composite measure of quality from fiscal year 2007 data based on 28 quality indicators from 112 Veterans Health Administration nursing homes. A Bayesian hierarchical multivariate normal-binomial model was used to estimate shrunken rates of the 28 quality indicators, which were combined into a composite measure using opportunity-based weights. Rates were estimated using Markov Chain Monte Carlo methods as implemented in WinBUGS. The probability metric was calculated from the simulation replications. Our probability metric allowed better discrimination of high performers than the point or interval estimate of the composite score. In a pay-for-performance program, a smaller top quantile (eg, a quintile) resulted in more resources being allocated to the highest performers, whereas a larger top quantile (eg, being above the median) distinguished less among high performers and allocated more resources to average performers. The probability metric has potential but needs to be evaluated by stakeholders in different types of delivery systems.

Reduced reference image quality assessment via sub-image similarity based redundancy measurement

NASA Astrophysics Data System (ADS)

Mou, Xuanqin; Xue, Wufeng; Zhang, Lei

2012-03-01

The reduced reference (RR) image quality assessment (IQA) has been attracting much attention from researchers for its loyalty to human perception and flexibility in practice. A promising RR metric should be able to predict the perceptual quality of an image accurately while using as few features as possible. In this paper, a novel RR metric is presented, whose novelty lies in two aspects. Firstly, it measures the image redundancy by calculating the so-called Sub-image Similarity (SIS), and the image quality is measured by comparing the SIS between the reference image and the test image. Secondly, the SIS is computed by the ratios of NSE (Non-shift Edge) between pairs of sub-images. Experiments on two IQA databases (i.e. LIVE and CSIQ databases) show that by using only 6 features, the proposed metric can work very well with high correlations between the subjective and objective scores. In particular, it works consistently well across all the distortion types.

Integrating automated support for a software management cycle into the TAME system

NASA Technical Reports Server (NTRS)

Sunazuka, Toshihiko; Basili, Victor R.

1989-01-01

Software managers are interested in the quantitative management of software quality, cost and progress. An integrated software management methodology, which can be applied throughout the software life cycle for any number purposes, is required. The TAME (Tailoring A Measurement Environment) methodology is based on the improvement paradigm and the goal/question/metric (GQM) paradigm. This methodology helps generate a software engineering process and measurement environment based on the project characteristics. The SQMAR (software quality measurement and assurance technology) is a software quality metric system and methodology applied to the development processes. It is based on the feed forward control principle. Quality target setting is carried out before the plan-do-check-action activities are performed. These methodologies are integrated to realize goal oriented measurement, process control and visual management. A metric setting procedure based on the GQM paradigm, a management system called the software management cycle (SMC), and its application to a case study based on NASA/SEL data are discussed. The expected effects of SMC are quality improvement, managerial cost reduction, accumulation and reuse of experience, and a highly visual management reporting system.

Trans-Pacific tele-ultrasound image transmission of fetal central nervous system structures.

PubMed

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.

Evaluating Core Quality for a Mars Sample Return Mission

NASA Technical Reports Server (NTRS)

Weiss, D. K.; Budney, C.; Shiraishi, L.; Klein, K.

2012-01-01

Sample return missions, including the proposed Mars Sample Return (MSR) mission, propose to collect core samples from scientifically valuable sites on Mars. These core samples would undergo extreme forces during the drilling process, and during the reentry process if the EEV (Earth Entry Vehicle) performed a hard landing on Earth. Because of the foreseen damage to the stratigraphy of the cores, it is important to evaluate each core for rock quality. However, because no core sample return mission has yet been conducted to another planetary body, it remains unclear as to how to assess the cores for rock quality. In this report, we describe the development of a metric designed to quantitatively assess the mechanical quality of any rock cores returned from Mars (or other planetary bodies). We report on the process by which we tested the metric on core samples of Mars analogue materials, and the effectiveness of the core assessment metric (CAM) in assessing rock core quality before and after the cores were subjected to shocking (g forces representative of an EEV landing).

Study of Temporal Effects on Subjective Video Quality of Experience.

PubMed

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.

Investigating the quality of video consultations performed using fourth generation (4G) mobile telecommunications.

PubMed

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.

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.

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.

PubMed

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.

Learning a Continuous-Time Streaming Video QoE Model.

PubMed

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.

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.

A model linking video gaming, sleep quality, sweet drinks consumption and obesity among children and youth.

PubMed

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.

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.

An exploratory survey of methods used to develop measures of performance

NASA Astrophysics Data System (ADS)

Hamner, Kenneth L.; Lafleur, Charles A.

1993-09-01

Nonmanufacturing organizations are being challenged to provide high-quality products and services to their customers, with an emphasis on continuous process improvement. Measures of performance, referred to as metrics, can be used to foster process improvement. The application of performance measurement to nonmanufacturing processes can be very difficult. This research explored methods used to develop metrics in nonmanufacturing organizations. Several methods were formally defined in the literature, and the researchers used a two-step screening process to determine the OMB Generic Method was most likely to produce high-quality metrics. The OMB Generic Method was then used to develop metrics. A few other metric development methods were found in use at nonmanufacturing organizations. The researchers interviewed participants in metric development efforts to determine their satisfaction and to have them identify the strengths and weaknesses of, and recommended improvements to, the metric development methods used. Analysis of participants' responses allowed the researchers to identify the key components of a sound metrics development method. Those components were incorporated into a proposed metric development method that was based on the OMB Generic Method, and should be more likely to produce high-quality metrics that will result in continuous process improvement.

Audiovisual quality estimation of mobile phone video cameras with interpretation-based quality approach

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.

A Comparison of Face to Face and Video-Based Self Care Education on Quality of Life of Hemodialysis Patients

PubMed Central

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

Sensors for 3D Imaging: Metric Evaluation and Calibration of a CCD/CMOS Time-of-Flight Camera.

PubMed

Chiabrando, Filiberto; Chiabrando, Roberto; Piatti, Dario; Rinaudo, Fulvio

2009-01-01

3D imaging with Time-of-Flight (ToF) cameras is a promising recent technique which allows 3D point clouds to be acquired at video frame rates. However, the distance measurements of these devices are often affected by some systematic errors which decrease the quality of the acquired data. In order to evaluate these errors, some experimental tests on a CCD/CMOS ToF camera sensor, the SwissRanger (SR)-4000 camera, were performed and reported in this paper. In particular, two main aspects are treated: the calibration of the distance measurements of the SR-4000 camera, which deals with evaluation of the camera warm up time period, the distance measurement error evaluation and a study of the influence on distance measurements of the camera orientation with respect to the observed object; the second aspect concerns the photogrammetric calibration of the amplitude images delivered by the camera using a purpose-built multi-resolution field made of high contrast targets.

Applying Sigma Metrics to Reduce Outliers.

PubMed

Litten, Joseph

2017-03-01

Sigma metrics can be used to predict assay quality, allowing easy comparison of instrument quality and predicting which tests will require minimal quality control (QC) rules to monitor the performance of the method. A Six Sigma QC program can result in fewer controls and fewer QC failures for methods with a sigma metric of 5 or better. The higher the number of methods with a sigma metric of 5 or better, the lower the costs for reagents, supplies, and control material required to monitor the performance of the methods. Copyright © 2016 Elsevier Inc. All rights reserved.

Exploring s-CIELAB as a scanner metric for print uniformity

NASA Astrophysics Data System (ADS)

Hertel, Dirk W.

2005-01-01

The s-CIELAB color difference metric combines the standard CIELAB metric for perceived color difference with spatial contrast sensitivity filtering. When studying the performance of digital image processing algorithms, maps of spatial color difference between 'before' and 'after' images are a measure of perceived image difference. A general image quality metric can be obtained by modeling the perceived difference from an ideal image. This paper explores the s-CIELAB concept for evaluating the quality of digital prints. Prints present the challenge that the 'ideal print' which should serve as the reference when calculating the delta E* error map is unknown, and thus be estimated from the scanned print. A reasonable estimate of what the ideal print 'should have been' is possible at least for images of known content such as flat fields or continuous wedges, where the error map can be calculated against a global or local mean. While such maps showing the perceived error at each pixel are extremely useful when analyzing print defects, it is desirable to statistically reduce them to a more manageable dataset. Examples of digital print uniformity are given, and the effect of specific print defects on the s-CIELAB delta E* metric are discussed.

The power metric: a new statistically robust enrichment-type metric for virtual screening applications with early recovery capability.

PubMed

Lopes, Julio Cesar Dias; Dos Santos, Fábio Mendes; Martins-José, Andrelly; Augustyns, Koen; De Winter, Hans

2017-01-01

A new metric for the evaluation of model performance in the field of virtual screening and quantitative structure-activity relationship applications is described. This metric has been termed the power metric and is defined as the fraction of the true positive rate divided by the sum of the true positive and false positive rates, for a given cutoff threshold. The performance of this metric is compared with alternative metrics such as the enrichment factor, the relative enrichment factor, the receiver operating curve enrichment factor, the correct classification rate, Matthews correlation coefficient and Cohen's kappa coefficient. The performance of this new metric is found to be quite robust with respect to variations in the applied cutoff threshold and ratio of the number of active compounds to the total number of compounds, and at the same time being sensitive to variations in model quality. It possesses the correct characteristics for its application in early-recognition virtual screening problems.

Investigating emergency room service quality using lean manufacturing.

PubMed

Abdelhadi, Abdelhakim

2015-01-01

The purpose of this paper is to investigate a lean manufacturing metric called Takt time as a benchmark evaluation measure to evaluate a public hospital's service quality. Lean manufacturing is an established managerial philosophy with a proven track record in industry. A lean metric called Takt time is applied as a measure to compare the relative efficiency between two emergency departments (EDs) belonging to the same public hospital. Outcomes guide managers to improve patient services and increase hospital performances. The patient treatment lead time within the hospital's two EDs (one department serves male and the other female patients) are the study's focus. A lean metric called Takt time is used to find the service's relative efficiency. Findings show that the lean manufacturing metric called Takt time can be used as an effective way to measure service efficiency by analyzing relative efficiency and identifies bottlenecks in different departments providing the same services. The paper presents a new procedure to compare relative efficiency between two EDs. It can be applied to any healthcare facility.

A Locally Weighted Fixation Density-Based Metric for Assessing the Quality of Visual Saliency Predictions

NASA Astrophysics Data System (ADS)

Gide, Milind S.; Karam, Lina J.

2016-08-01

With the increased focus on visual attention (VA) in the last decade, a large number of computational visual saliency methods have been developed over the past few years. These models are traditionally evaluated by using performance evaluation metrics that quantify the match between predicted saliency and fixation data obtained from eye-tracking experiments on human observers. Though a considerable number of such metrics have been proposed in the literature, there are notable problems in them. In this work, we discuss shortcomings in existing metrics through illustrative examples and propose a new metric that uses local weights based on fixation density which overcomes these flaws. To compare the performance of our proposed metric at assessing the quality of saliency prediction with other existing metrics, we construct a ground-truth subjective database in which saliency maps obtained from 17 different VA models are evaluated by 16 human observers on a 5-point categorical scale in terms of their visual resemblance with corresponding ground-truth fixation density maps obtained from eye-tracking data. The metrics are evaluated by correlating metric scores with the human subjective ratings. The correlation results show that the proposed evaluation metric outperforms all other popular existing metrics. Additionally, the constructed database and corresponding subjective ratings provide an insight into which of the existing metrics and future metrics are better at estimating the quality of saliency prediction and can be used as a benchmark.

The data quality analyzer: A quality control program for seismic data

NASA Astrophysics Data System (ADS)

Ringler, A. T.; Hagerty, M. T.; Holland, J.; Gonzales, A.; Gee, L. S.; Edwards, J. D.; Wilson, D.; Baker, A. M.

2015-03-01

The U.S. Geological Survey's Albuquerque Seismological Laboratory (ASL) has several initiatives underway to enhance and track the quality of data produced from ASL seismic stations and to improve communication about data problems to the user community. The Data Quality Analyzer (DQA) is one such development and is designed to characterize seismic station data quality in a quantitative and automated manner. The DQA consists of a metric calculator, a PostgreSQL database, and a Web interface: The metric calculator, SEEDscan, is a Java application that reads and processes miniSEED data and generates metrics based on a configuration file. SEEDscan compares hashes of metadata and data to detect changes in either and performs subsequent recalculations as needed. This ensures that the metric values are up to date and accurate. SEEDscan can be run as a scheduled task or on demand. The PostgreSQL database acts as a central hub where metric values and limited station descriptions are stored at the channel level with one-day granularity. The Web interface dynamically loads station data from the database and allows the user to make requests for time periods of interest, review specific networks and stations, plot metrics as a function of time, and adjust the contribution of various metrics to the overall quality grade of the station. The quantification of data quality is based on the evaluation of various metrics (e.g., timing quality, daily noise levels relative to long-term noise models, and comparisons between broadband data and event synthetics). Users may select which metrics contribute to the assessment and those metrics are aggregated into a "grade" for each station. The DQA is being actively used for station diagnostics and evaluation based on the completed metrics (availability, gap count, timing quality, deviation from a global noise model, deviation from a station noise model, coherence between co-located sensors, and comparison between broadband data and synthetics for earthquakes) on stations in the Global Seismographic Network and Advanced National Seismic System.

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.

A unified framework of unsupervised subjective optimized bit allocation for multiple video object coding

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.

Network-aware scalable video monitoring system for emergency situations with operator-managed fidelity control

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.

YouTube as a potential training method for laparoscopic cholecystectomy.

PubMed

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.

Is perception of quality more important than technical quality in patient video cases?

PubMed

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.

Academic podcasting: quality media delivery.

PubMed

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.

Development and Implementation of a Design Metric for Systems Containing Long-Term Fluid Loops

NASA Technical Reports Server (NTRS)

Steele, John W.

2016-01-01

John Steele, a chemist and technical fellow from United Technologies Corporation, provided a water quality module to assist engineers and scientists with a metric tool to evaluate risks associated with the design of space systems with fluid loops. This design metric is a methodical, quantitative, lessons-learned based means to evaluate the robustness of a long-term fluid loop system design. The tool was developed by a cross-section of engineering disciplines who had decades of experience and problem resolution.

Real time biometric surveillance with gait recognition

NASA Astrophysics Data System (ADS)

Mohapatra, Subasish; Swain, Anisha; Das, Manaswini; Mohanty, Subhadarshini

2018-04-01

Bio metric surveillance has become indispensable for every system in the recent years. The contribution of bio metric authentication, identification, and screening purposes are widely used in various domains for preventing unauthorized access. A large amount of data needs to be updated, segregated and safeguarded from malicious software and misuse. Bio metrics is the intrinsic characteristics of each individual. Recently fingerprints, iris, passwords, unique keys, and cards are commonly used for authentication purposes. These methods have various issues related to security and confidentiality. These systems are not yet automated to provide the safety and security. The gait recognition system is the alternative for overcoming the drawbacks of the recent bio metric based authentication systems. Gait recognition is newer as it hasn't been implemented in the real-world scenario so far. This is an un-intrusive system that requires no knowledge or co-operation of the subject. Gait is a unique behavioral characteristic of every human being which is hard to imitate. The walking style of an individual teamed with the orientation of joints in the skeletal structure and inclinations between them imparts the unique characteristic. A person can alter one's own external appearance but not skeletal structure. These are real-time, automatic systems that can even process low-resolution images and video frames. In this paper, we have proposed a gait recognition system and compared the performance with conventional bio metric identification systems.

A blinded assessment of video quality in wearable technology for telementoring in open surgery: the Google Glass experience.

PubMed

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 as a Potential Training Resource for Laparoscopic Fundoplication.

PubMed

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.

Clinician Ratings of Interpreter Mediated Visits in Underserved Primary Care Settings with Ad hoc, In-person Professional, and Video Conferencing Modes

PubMed Central

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

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…

Estimation of velocities via optical flow

NASA Astrophysics Data System (ADS)

Popov, A.; Miller, A.; Miller, B.; Stepanyan, K.

2017-02-01

This article presents an approach to the optical flow (OF) usage as a general navigation means providing the information about the linear and angular vehicle's velocities. The term of "OF" came from opto-electronic devices where it corresponds to a video sequence of images related to the camera motion either over static surfaces or set of objects. Even if the positions of these objects are unknown in advance, one can estimate the camera motion provided just by video sequence itself and some metric information, such as distance between the objects or the range to the surface. This approach is applicable to any passive observation system which is able to produce a sequence of images, such as radio locator or sonar. Here the UAV application of the OF is considered since it is historically

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.

YouTube as a potential training method for laparoscopic cholecystectomy

PubMed Central

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

On the definition of adapted audio/video profiles for high-quality video calling services over LTE/4G

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).

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.

Comparing masked target transform volume (MTTV) clutter metric to human observer evaluation of visual clutter

NASA Astrophysics Data System (ADS)

Camp, H. A.; Moyer, Steven; Moore, Richard K.

2010-04-01

The Night Vision and Electronic Sensors Directorate's current time-limited search (TLS) model, which makes use of the targeting task performance (TTP) metric to describe image quality, does not explicitly account for the effects of visual clutter on observer performance. The TLS model is currently based on empirical fits to describe human performance for a time of day, spectrum and environment. Incorporating a clutter metric into the TLS model may reduce the number of these empirical fits needed. The masked target transform volume (MTTV) clutter metric has been previously presented and compared to other clutter metrics. Using real infrared imagery of rural images with varying levels of clutter, NVESD is currently evaluating the appropriateness of the MTTV metric. NVESD had twenty subject matter experts (SME) rank the amount of clutter in each scene in a series of pair-wise comparisons. MTTV metric values were calculated and then compared to the SME observers rankings. The MTTV metric ranked the clutter in a similar manner to the SME evaluation, suggesting that the MTTV metric may emulate SME response. This paper is a first step in quantifying clutter and measuring the agreement to subjective human evaluation.

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.

Evaluation techniques and metrics for assessment of pan+MSI fusion (pansharpening)

NASA Astrophysics Data System (ADS)

Mercovich, Ryan A.

2015-05-01

Fusion of broadband panchromatic data with narrow band multispectral data - pansharpening - is a common and often studied problem in remote sensing. Many methods exist to produce data fusion results with the best possible spatial and spectral characteristics, and a number have been commercially implemented. This study examines the output products of 4 commercial implementations with regard to their relative strengths and weaknesses for a set of defined image characteristics and analyst use-cases. Image characteristics used are spatial detail, spatial quality, spectral integrity, and composite color quality (hue and saturation), and analyst use-cases included a variety of object detection and identification tasks. The imagery comes courtesy of the RIT SHARE 2012 collect. Two approaches are used to evaluate the pansharpening methods, analyst evaluation or qualitative measure and image quality metrics or quantitative measures. Visual analyst evaluation results are compared with metric results to determine which metrics best measure the defined image characteristics and product use-cases and to support future rigorous characterization the metrics' correlation with the analyst results. Because pansharpening represents a trade between adding spatial information from the panchromatic image, and retaining spectral information from the MSI channels, the metrics examined are grouped into spatial improvement metrics and spectral preservation metrics. A single metric to quantify the quality of a pansharpening method would necessarily be a combination of weighted spatial and spectral metrics based on the importance of various spatial and spectral characteristics for the primary task of interest. Appropriate metrics and weights for such a combined metric are proposed here, based on the conducted analyst evaluation. Additionally, during this work, a metric was developed specifically focused on assessment of spatial structure improvement relative to a reference image and independent of scene content. Using analysis of Fourier transform images, a measure of high-frequency content is computed in small sub-segments of the image. The average increase in high-frequency content across the image is used as the metric, where averaging across sub-segments combats the scene dependent nature of typical image sharpness techniques. This metric had an improved range of scores, better representing difference in the test set than other common spatial structure metrics.

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.

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.

A professional and cost effective digital video editing and image storage system for the operating room.

PubMed

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.

Improvement of impact noise in a passenger car utilizing sound metric based on wavelet transform

NASA Astrophysics Data System (ADS)

Lee, Sang-Kwon; Kim, Ho-Wuk; Na, Eun-Woo

2010-08-01

A new sound metric for impact sound is developed based on the continuous wavelet transform (CWT), a useful tool for the analysis of non-stationary signals such as impact noise. Together with new metric, two other conventional sound metrics related to sound modulation and fluctuation are also considered. In all, three sound metrics are employed to develop impact sound quality indexes for several specific impact courses on the road. Impact sounds are evaluated subjectively by 25 jurors. The indexes are verified by comparing the correlation between the index output and results of a subjective evaluation based on a jury test. These indexes are successfully applied to an objective evaluation for improvement of the impact sound quality for cases where some parts of the suspension system of the test car are modified.

Objective Video Quality Assessment Based on Machine Learning for Underwater Scientific Applications

PubMed Central

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

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)

Recognizing human activities using appearance metric feature and kinematics feature

NASA Astrophysics Data System (ADS)

Qian, Huimin; Zhou, Jun; Lu, Xinbiao; Wu, Xinye

2017-05-01

The problem of automatically recognizing human activities from videos through the fusion of the two most important cues, appearance metric feature and kinematics feature, is considered. And a system of two-dimensional (2-D) Poisson equations is introduced to extract the more discriminative appearance metric feature. Specifically, the moving human blobs are first detected out from the video by background subtraction technique to form a binary image sequence, from which the appearance feature designated as the motion accumulation image and the kinematics feature termed as centroid instantaneous velocity are extracted. Second, 2-D discrete Poisson equations are employed to reinterpret the motion accumulation image to produce a more differentiated Poisson silhouette image, from which the appearance feature vector is created through the dimension reduction technique called bidirectional 2-D principal component analysis, considering the balance between classification accuracy and time consumption. Finally, a cascaded classifier based on the nearest neighbor classifier and two directed acyclic graph support vector machine classifiers, integrated with the fusion of the appearance feature vector and centroid instantaneous velocity vector, is applied to recognize the human activities. Experimental results on the open databases and a homemade one confirm the recognition performance of the proposed algorithm.

Full-frame video stabilization with motion inpainting.

PubMed

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.

Rendering-based video-CT registration with physical constraints for image-guided endoscopic sinus surgery

NASA Astrophysics Data System (ADS)

Otake, Y.; Leonard, S.; Reiter, A.; Rajan, P.; Siewerdsen, J. H.; Ishii, M.; Taylor, R. H.; Hager, G. D.

2015-03-01

We present a system for registering the coordinate frame of an endoscope to pre- or intra- operatively acquired CT data based on optimizing the similarity metric between an endoscopic image and an image predicted via rendering of CT. Our method is robust and semi-automatic because it takes account of physical constraints, specifically, collisions between the endoscope and the anatomy, to initialize and constrain the search. The proposed optimization method is based on a stochastic optimization algorithm that evaluates a large number of similarity metric functions in parallel on a graphics processing unit. Images from a cadaver and a patient were used for evaluation. The registration error was 0.83 mm and 1.97 mm for cadaver and patient images respectively. The average registration time for 60 trials was 4.4 seconds. The patient study demonstrated robustness of the proposed algorithm against a moderate anatomical deformation.

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

PubMed Central

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

Efficient data replication for the delivery of high-quality video content over P2P VoD advertising networks

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.

VQone MATLAB toolbox: A graphical experiment builder for image and video quality evaluations: VQone MATLAB toolbox.

PubMed

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/).

Driving photomask supplier quality through automation

NASA Astrophysics Data System (ADS)

Russell, Drew; Espenscheid, Andrew

2007-10-01

In 2005, Freescale Semiconductor's newly centralized mask data prep organization (MSO) initiated a project to develop an automated global quality validation system for photomasks delivered to Freescale Semiconductor fabs. The system handles Certificate of Conformance (CofC) quality metric collection, validation, reporting and an alert system for all photomasks shipped to Freescale fabs from all qualified global suppliers. The completed system automatically collects 30+ quality metrics for each photomask shipped. Other quality metrics are generated from the collected data and quality metric conformance is automatically validated to specifications or control limits with failure alerts emailed to fab photomask and mask data prep engineering. A quality data warehouse stores the data for future analysis, which is performed quarterly. The improved access to data provided by the system has improved Freescale engineers' ability to spot trends and opportunities for improvement with our suppliers' processes. This paper will review each phase of the project, current system capabilities and quality system benefits for both our photomask suppliers and Freescale.

Multivariate Analyses of Quality Metrics for Crystal Structures in the PDB Archive.

PubMed

Shao, Chenghua; Yang, Huanwang; Westbrook, John D; Young, Jasmine Y; Zardecki, Christine; Burley, Stephen K

2017-03-07

Following deployment of an augmented validation system by the Worldwide Protein Data Bank (wwPDB) partnership, the quality of crystal structures entering the PDB has improved. Of significance are improvements in quality measures now prominently displayed in the wwPDB validation report. Comparisons of PDB depositions made before and after introduction of the new reporting system show improvements in quality measures relating to pairwise atom-atom clashes, side-chain torsion angle rotamers, and local agreement between the atomic coordinate structure model and experimental electron density data. These improvements are largely independent of resolution limit and sample molecular weight. No significant improvement in the quality of associated ligands was observed. Principal component analysis revealed that structure quality could be summarized with three measures (Rfree, real-space R factor Z score, and a combined molecular geometry quality metric), which can in turn be reduced to a single overall quality metric readily interpretable by all PDB archive users. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of landscape disturbance on the quality of terrestrial sediment carbon in temperate streams

NASA Astrophysics Data System (ADS)

Fox, James F.; Ford, William I.

2016-09-01

Recent studies have shown the super saturation of fluvial networks with respect to carbon dioxide, and the concept that the high carbon dioxide is at least partially the result of turnover of sediment organic carbon that ranges in age from years to millennia. Currently, there is a need for more highly resolved studies at stream and river scales that enable estimates of terrestrial carbon turnover within fluvial networks. Our objective was to develop a new isotope-based metric to estimate the quality of sediment organic carbon delivered to temperate streams and to use the new metric to estimate carbon quality across landscape disturbance gradients. Carbon quality is defined to be consistent with in-stream turnover and our metric is used to measure the labile or recalcitrant nature of the terrestrial-derived carbon within streams. Our hypothesis was that intensively-disturbed landscapes would tend to produce low quality carbon because deep, recalcitrant soil carbon would be eroded and transported to the fluvial system while moderately disturbed or undisturbed landscapes would tend to produce higher quality carbon from well-developed surface soils and litter. The hypothesis was tested by applying the new carbon quality metric to 15 temperate streams with a wide range of landscape disturbance levels. We find that our hypothesis premised on an indirect relationship between the extent of landscape disturbance and the quality of sediment carbon in streams holds true for moderate and high disturbances but not for un-disturbed forests. We explain the results based on the connectivity, or dis-connectivity, between terrestrial carbon sources and pathways for sediment transport. While pathways are typically un-limited for disturbed landscapes, the un-disturbed forests have dis-connectivity between labile carbon of the forest floor and the stream corridor. Only in the case when trees fell into the stream corridor due to severe ice storms did the quality of sediment carbon increase in the streams. We argue that as scientists continue to estimate the in-stream turnover of terrestrially-derived carbon in fluvial carbon budgets, the assumption of pathway connectivity between carbon sources to the stream should be justified.

Practical, Real-Time, and Robust Watermarking on the Spatial Domain for High-Definition Video Contents

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.

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.

Quality of experience enhancement of high efficiency video coding video streaming in wireless packet networks using multiple description coding

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.

Head-camera video recordings of trauma core competency procedures can evaluate surgical resident's technical performance as well as colocated evaluators.

PubMed

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.

Partially supervised speaker clustering.

PubMed

Tang, Hao; Chu, Stephen Mingyu; Hasegawa-Johnson, Mark; Huang, Thomas S

2012-05-01

Content-based multimedia indexing, retrieval, and processing as well as multimedia databases demand the structuring of the media content (image, audio, video, text, etc.), one significant goal being to associate the identity of the content to the individual segments of the signals. In this paper, we specifically address the problem of speaker clustering, the task of assigning every speech utterance in an audio stream to its speaker. We offer a complete treatment to the idea of partially supervised speaker clustering, which refers to the use of our prior knowledge of speakers in general to assist the unsupervised speaker clustering process. By means of an independent training data set, we encode the prior knowledge at the various stages of the speaker clustering pipeline via 1) learning a speaker-discriminative acoustic feature transformation, 2) learning a universal speaker prior model, and 3) learning a discriminative speaker subspace, or equivalently, a speaker-discriminative distance metric. We study the directional scattering property of the Gaussian mixture model (GMM) mean supervector representation of utterances in the high-dimensional space, and advocate exploiting this property by using the cosine distance metric instead of the euclidean distance metric for speaker clustering in the GMM mean supervector space. We propose to perform discriminant analysis based on the cosine distance metric, which leads to a novel distance metric learning algorithm—linear spherical discriminant analysis (LSDA). We show that the proposed LSDA formulation can be systematically solved within the elegant graph embedding general dimensionality reduction framework. Our speaker clustering experiments on the GALE database clearly indicate that 1) our speaker clustering methods based on the GMM mean supervector representation and vector-based distance metrics outperform traditional speaker clustering methods based on the “bag of acoustic features” representation and statistical model-based distance metrics, 2) our advocated use of the cosine distance metric yields consistent increases in the speaker clustering performance as compared to the commonly used euclidean distance metric, 3) our partially supervised speaker clustering concept and strategies significantly improve the speaker clustering performance over the baselines, and 4) our proposed LSDA algorithm further leads to state-of-the-art speaker clustering performance.

International Space Station (ISS)

NASA Image and Video Library

2000-12-04

This video still depicts the recently deployed starboard and port solar arrays towering over the International Space Station (ISS). The video was recorded on STS-97's 65th orbit. Delivery, assembly, and activation of the solar arrays was the main mission objective of STS-97. The electrical power system, which is built into a 73-meter (240-foot) long solar array structure consists of solar arrays, radiators, batteries, and electronics, and will provide the power necessary for the first ISS crews to live and work in the U.S. segment. The entire 15.4-metric ton (17-ton) package is called the P6 Integrated Truss Segment, and is the heaviest and largest element yet delivered to the station aboard a space shuttle. The STS-97 crew of five launched aboard the Space Shuttle Orbiter Endeavor on November 30, 2000 for an 11 day mission.

Self-supervised online metric learning with low rank constraint for scene categorization.

PubMed

Cong, Yang; Liu, Ji; Yuan, Junsong; Luo, Jiebo

2013-08-01

Conventional visual recognition systems usually train an image classifier in a bath mode with all training data provided in advance. However, in many practical applications, only a small amount of training samples are available in the beginning and many more would come sequentially during online recognition. Because the image data characteristics could change over time, it is important for the classifier to adapt to the new data incrementally. In this paper, we present an online metric learning method to address the online scene recognition problem via adaptive similarity measurement. Given a number of labeled data followed by a sequential input of unseen testing samples, the similarity metric is learned to maximize the margin of the distance among different classes of samples. By considering the low rank constraint, our online metric learning model not only can provide competitive performance compared with the state-of-the-art methods, but also guarantees convergence. A bi-linear graph is also defined to model the pair-wise similarity, and an unseen sample is labeled depending on the graph-based label propagation, while the model can also self-update using the more confident new samples. With the ability of online learning, our methodology can well handle the large-scale streaming video data with the ability of incremental self-updating. We evaluate our model to online scene categorization and experiments on various benchmark datasets and comparisons with state-of-the-art methods demonstrate the effectiveness and efficiency of our algorithm.

A Novel Approach to High Definition, High-Contrast Video Capture in Abdominal Surgery

PubMed Central

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

Efficacy of video-music therapy on quality of life improvement in a group of patients with Alzheimer's disease: a pre-post study.

PubMed

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.

Compressed ultrasound video image-quality evaluation using a Likert scale and Kappa statistical analysis

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.

Program Manager: Journal of the Defense Systems Management College. Volume 19, Number 5, September-October 1990

DTIC Science & Technology

1990-10-01

International Defense Cooperation Agreements; Quality Force Deployment; How Contractors See Systems Acquisition; DOD Metric Transition Plans and Actions; Proposals for Innovation In Service Quality . (sdw)

Efficacy of single and multi-metric fish-based indices in tracking anthropogenic pressures in estuaries: An 8-year case study.

PubMed

Martinho, Filipe; Nyitrai, Daniel; Crespo, Daniel; Pardal, Miguel A

2015-12-15

Facing a generalized increase in water degradation, several programmes have been implemented for protecting and enhancing the water quality and associated wildlife, which rely on ecological indicators to assess the degree of deviation from a pristine state. Here, single (species number, Shannon-Wiener H', Pielou J') and multi-metric (Estuarine Fish Assessment Index, EFAI) community-based ecological quality measures were evaluated in a temperate estuary over an 8-year period (2005-2012), and established their relationships with an anthropogenic pressure index (API). Single metric indices were highly variable and neither concordant amongst themselves nor with the EFAI. The EFAI was the only index significantly correlated with the API, indicating that higher ecological quality was associated with lower anthropogenic pressure. Pressure scenarios were related with specific fish community composition, as a result of distinct food web complexity and nursery functioning of the estuary. Results were discussed in the scope of the implementation of water protection programmes. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Subjective Quality Assessment of Underwater Video for Scientific Applications

PubMed Central

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

Future of the PCI Readmission Metric.

PubMed

Wasfy, Jason H; Yeh, Robert W

2016-03-01

Between 2013 and 2014, the Centers for Medicare and Medicaid Services and the National Cardiovascular Data Registry publically reported risk-adjusted 30-day readmission rates after percutaneous coronary intervention (PCI) as a pilot project. A key strength of this public reporting effort included risk adjustment with clinical rather than administrative data. Furthermore, because readmission after PCI is common, expensive, and preventable, this metric has substantial potential to improve quality and value in American cardiology care. Despite this, concerns about the metric exist. For example, few PCI readmissions are caused by procedural complications, limiting the extent to which improved procedural technique can reduce readmissions. Also, similar to other readmission measures, PCI readmission is associated with socioeconomic status and race. Accordingly, the metric may unfairly penalize hospitals that care for underserved patients. Perhaps in the context of these limitations, Centers for Medicare and Medicaid Services has not yet included PCI readmission among metrics that determine Medicare financial penalties. Nevertheless, provider organizations may still wish to focus on this metric to improve value for cardiology patients. PCI readmission is associated with low-risk chest discomfort and patient anxiety. Therefore, patient education, improved triage mechanisms, and improved care coordination offer opportunities to minimize PCI readmissions. Because PCI readmission is common and costly, reducing PCI readmission offers provider organizations a compelling target to improve the quality of care, and also performance in contracts involve shared financial risk. © 2016 American Heart Association, Inc.

Subjective Quality Assessment of Underwater Video for Scientific Applications.

PubMed

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.

Heterogeneous sharpness for cross-spectral face recognition

NASA Astrophysics Data System (ADS)

Cao, Zhicheng; Schmid, Natalia A.

2017-05-01

Matching images acquired in different electromagnetic bands remains a challenging problem. An example of this type of comparison is matching active or passive infrared (IR) against a gallery of visible face images, known as cross-spectral face recognition. Among many unsolved issues is the one of quality disparity of the heterogeneous images. Images acquired in different spectral bands are of unequal image quality due to distinct imaging mechanism, standoff distances, or imaging environment, etc. To reduce the effect of quality disparity on the recognition performance, one can manipulate images to either improve the quality of poor-quality images or to degrade the high-quality images to the level of the quality of their heterogeneous counterparts. To estimate the level of discrepancy in quality of two heterogeneous images a quality metric such as image sharpness is needed. It provides a guidance in how much quality improvement or degradation is appropriate. In this work we consider sharpness as a relative measure of heterogeneous image quality. We propose a generalized definition of sharpness by first achieving image quality parity and then finding and building a relationship between the image quality of two heterogeneous images. Therefore, the new sharpness metric is named heterogeneous sharpness. Image quality parity is achieved by experimentally finding the optimal cross-spectral face recognition performance where quality of the heterogeneous images is varied using a Gaussian smoothing function with different standard deviation. This relationship is established using two models; one of them involves a regression model and the other involves a neural network. To train, test and validate the model, we use composite operators developed in our lab to extract features from heterogeneous face images and use the sharpness metric to evaluate the face image quality within each band. Images from three different spectral bands visible light, near infrared, and short-wave infrared are considered in this work. Both error of a regression model and validation error of a neural network are analyzed.

Sleep quality is negatively related to video gaming volume in adults.

PubMed

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.

Cardiac ultrasonography over 4G wireless networks using a tele-operated robot

PubMed Central

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

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…

Educational Colonoscopy Video Enhances Bowel Preparation Quality and Comprehension in an Inner City Population.

PubMed

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).

Graphics to H.264 video encoding for 3D scene representation and interaction on mobile devices using region of interest

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.

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.

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.

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…

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.

Automatic red eye correction and its quality metric

NASA Astrophysics Data System (ADS)

Safonov, Ilia V.; Rychagov, Michael N.; Kang, KiMin; Kim, Sang Ho

2008-01-01

The red eye artifacts are troublesome defect of amateur photos. Correction of red eyes during printing without user intervention and making photos more pleasant for an observer are important tasks. The novel efficient technique of automatic correction of red eyes aimed for photo printers is proposed. This algorithm is independent from face orientation and capable to detect paired red eyes as well as single red eyes. The approach is based on application of 3D tables with typicalness levels for red eyes and human skin tones and directional edge detection filters for processing of redness image. Machine learning is applied for feature selection. For classification of red eye regions a cascade of classifiers including Gentle AdaBoost committee from Classification and Regression Trees (CART) is applied. Retouching stage includes desaturation, darkening and blending with initial image. Several versions of approach implementation using trade-off between detection and correction quality, processing time, memory volume are possible. The numeric quality criterion of automatic red eye correction is proposed. This quality metric is constructed by applying Analytic Hierarchy Process (AHP) for consumer opinions about correction outcomes. Proposed numeric metric helped to choose algorithm parameters via optimization procedure. Experimental results demonstrate high accuracy and efficiency of the proposed algorithm in comparison with existing solutions.

Evaluation of in-network adaptation of scalable high efficiency video coding (SHVC) in mobile environments

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.

Evaluation of differences in quality of experience features for test stimuli of good-only and bad-only overall audiovisual quality

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.

App Usage Factor: A Simple Metric to Compare the Population Impact of Mobile Medical Apps.

PubMed

Lewis, Thomas Lorchan; Wyatt, Jeremy C

2015-08-19

One factor when assessing the quality of mobile apps is quantifying the impact of a given app on a population. There is currently no metric which can be used to compare the population impact of a mobile app across different health care disciplines. The objective of this study is to create a novel metric to characterize the impact of a mobile app on a population. We developed the simple novel metric, app usage factor (AUF), defined as the logarithm of the product of the number of active users of a mobile app with the median number of daily uses of the app. The behavior of this metric was modeled using simulated modeling in Python, a general-purpose programming language. Three simulations were conducted to explore the temporal and numerical stability of our metric and a simulated app ecosystem model using a simulated dataset of 20,000 apps. Simulations confirmed the metric was stable between predicted usage limits and remained stable at extremes of these limits. Analysis of a simulated dataset of 20,000 apps calculated an average value for the app usage factor of 4.90 (SD 0.78). A temporal simulation showed that the metric remained stable over time and suitable limits for its use were identified. A key component when assessing app risk and potential harm is understanding the potential population impact of each mobile app. Our metric has many potential uses for a wide range of stakeholders in the app ecosystem, including users, regulators, developers, and health care professionals. Furthermore, this metric forms part of the overall estimate of risk and potential for harm or benefit posed by a mobile medical app. We identify the merits and limitations of this metric, as well as potential avenues for future validation and research.

An observational clinical and video-polysomnographic study of the effects of rotigotine in sleep disorder in Parkinson's disease.

PubMed

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.

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.

Active and passive spatial learning in human navigation: acquisition of survey knowledge.

PubMed

Chrastil, Elizabeth R; Warren, William H

2013-09-01

It seems intuitively obvious that active exploration of a new environment would lead to better spatial learning than would passive visual exposure. It is unclear, however, which components of active learning contribute to spatial knowledge, and previous literature is decidedly mixed. This experiment tests the contributions of 4 components to metric survey knowledge: visual, vestibular, and podokinetic information and cognitive decision making. In the learning phase, 6 groups of participants learned the locations of 8 objects in a virtual hedge maze by (a) walking, (b) being pushed in a wheelchair, or (c) watching a video, crossed with (1) making decisions about their path or (2) being guided through the maze. In the test phase, survey knowledge was assessed by having participants walk a novel shortcut from a starting object to the remembered location of a test object, with the maze removed. Performance was slightly better than chance in the passive video condition. The addition of vestibular information did not improve performance in the wheelchair condition, but the addition of podokinetic information significantly improved angular accuracy in the walking condition. In contrast, there was no effect of decision making in any condition. The results indicate that visual and podokinetic information significantly contribute to survey knowledge, whereas vestibular information and decision making do not. We conclude that podokinetic information is the primary component of active learning for the acquisition of metric survey knowledge. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Content-based management service for medical videos.

PubMed

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.

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.

78 FR 52195 - Announcement of Requirements and Registration for “Healthy Young America Video Contest”

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...

Development and application of a novel metric to assess effectiveness of biomedical data

PubMed Central

Bloom, Gregory C; Eschrich, Steven; Hang, Gang; Schabath, Matthew B; Bhansali, Neera; Hoerter, Andrew M; Morgan, Scott; Fenstermacher, David A

2013-01-01

Objective Design a metric to assess the comparative effectiveness of biomedical data elements within a study that incorporates their statistical relatedness to a given outcome variable as well as a measurement of the quality of their underlying data. Materials and methods The cohort consisted of 874 patients with adenocarcinoma of the lung, each with 47 clinical data elements. The p value for each element was calculated using the Cox proportional hazard univariable regression model with overall survival as the endpoint. An attribute or A-score was calculated by quantification of an element's four quality attributes; Completeness, Comprehensiveness, Consistency and Overall-cost. An effectiveness or E-score was obtained by calculating the conditional probabilities of the p-value and A-score within the given data set with their product equaling the effectiveness score (E-score). Results The E-score metric provided information about the utility of an element beyond an outcome-related p value ranking. E-scores for elements age-at-diagnosis, gender and tobacco-use showed utility above what their respective p values alone would indicate due to their relative ease of acquisition, that is, higher A-scores. Conversely, elements surgery-site, histologic-type and pathological-TNM stage were down-ranked in comparison to their p values based on lower A-scores caused by significantly higher acquisition costs. Conclusions A novel metric termed E-score was developed which incorporates standard statistics with data quality metrics and was tested on elements from a large lung cohort. Results show that an element's underlying data quality is an important consideration in addition to p value correlation to outcome when determining the element's clinical or research utility in a study. PMID:23975264

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.

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.

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...

Potential usefulness of a video printer for producing secondary images from digitized chest radiographs

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).

A Linear Algebra Measure of Cluster Quality.

ERIC Educational Resources Information Center

Mather, Laura A.

2000-01-01

Discussion of models for information retrieval focuses on an application of linear algebra to text clustering, namely, a metric for measuring cluster quality based on the theory that cluster quality is proportional to the number of terms that are disjoint across the clusters. Explains term-document matrices and clustering algorithms. (Author/LRW)

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.

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.

MobileASL: intelligibility of sign language video over mobile phones.

PubMed

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.

Quantitative Analysis of Color Differences within High Contrast, Low Power Reversible Electrophoretic Displays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giera, Brian; Bukosky, Scott; Lee, Elaine

Here, quantitative color analysis is performed on videos of high contrast, low power reversible electrophoretic deposition (EPD)-based displays operated under different applied voltages. This analysis is coded in an open-source software, relies on a color differentiation metric, ΔE * 00, derived from digital video, and provides an intuitive relationship between the operating conditions of the devices and their performance. Time-dependent ΔE * 00 color analysis reveals color relaxation behavior, recoverability for different voltage sequences, and operating conditions that can lead to optimal performance.

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.

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.

Quantitative Analysis of Color Differences within High Contrast, Low Power Reversible Electrophoretic Displays

DOE PAGES

Giera, Brian; Bukosky, Scott; Lee, Elaine; ...

2018-01-23

Here, quantitative color analysis is performed on videos of high contrast, low power reversible electrophoretic deposition (EPD)-based displays operated under different applied voltages. This analysis is coded in an open-source software, relies on a color differentiation metric, ΔE * 00, derived from digital video, and provides an intuitive relationship between the operating conditions of the devices and their performance. Time-dependent ΔE * 00 color analysis reveals color relaxation behavior, recoverability for different voltage sequences, and operating conditions that can lead to optimal performance.

Secure and Efficient Reactive Video Surveillance for Patient Monitoring.

PubMed

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

PubMed Central

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

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.

Participant satisfaction with appearance-based versus health-based educational videos promoting sunscreen use: a randomized controlled trial.

PubMed

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.

For Video Games, Bad News Is Good News: News Reporting of Violent Video Game Studies.

PubMed

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.

The Albuquerque Seismological Laboratory Data Quality Analyzer

NASA Astrophysics Data System (ADS)

Ringler, A. T.; Hagerty, M.; Holland, J.; Gee, L. S.; Wilson, D.

2013-12-01

The U.S. Geological Survey's Albuquerque Seismological Laboratory (ASL) has several efforts underway to improve data quality at its stations. The Data Quality Analyzer (DQA) is one such development. The DQA is designed to characterize station data quality in a quantitative and automated manner. Station quality is based on the evaluation of various metrics, such as timing quality, noise levels, sensor coherence, and so on. These metrics are aggregated into a measurable grade for each station. The DQA consists of a website, a metric calculator (Seedscan), and a PostgreSQL database. The website allows the user to make requests for various time periods, review specific networks and stations, adjust weighting of the station's grade, and plot metrics as a function of time. The website dynamically loads all station data from a PostgreSQL database. The database is central to the application; it acts as a hub where metric values and limited station descriptions are stored. Data is stored at the level of one sensor's channel per day. The database is populated by Seedscan. Seedscan reads and processes miniSEED data, to generate metric values. Seedscan, written in Java, compares hashes of metadata and data to detect changes and perform subsequent recalculations. This ensures that the metric values are up to date and accurate. Seedscan can be run in a scheduled task or on demand by way of a config file. It will compute metrics specified in its configuration file. While many metrics are currently in development, some are completed and being actively used. These include: availability, timing quality, gap count, deviation from the New Low Noise Model, deviation from a station's noise baseline, inter-sensor coherence, and data-synthetic fits. In all, 20 metrics are planned, but any number could be added. ASL is actively using the DQA on a daily basis for station diagnostics and evaluation. As Seedscan is scheduled to run every night, data quality analysts are able to then use the website to diagnose changes in noise levels or other anomalous data. This allows for errors to be corrected quickly and efficiently. The code is designed to be flexible for adding metrics and portable for use in other networks. We anticipate further development of the DQA by improving the existing web-interface, adding more metrics, adding an interface to facilitate the verification of historic station metadata and performance, and an interface to allow better monitoring of data quality goals.

Modeling the time--varying subjective quality of HTTP video streams with rate adaptations.

PubMed

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.

Effects of music and music video interventions on sleep quality: A randomized controlled trial in adults with sleep disturbances.

PubMed

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.

Interactive Video Coding and Transmission over Heterogeneous Wired-to-Wireless IP Networks Using an Edge Proxy

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.

SU-E-I-71: Quality Assessment of Surrogate Metrics in Multi-Atlas-Based Image Segmentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, T; Ruan, D

Purpose: With the ever-growing data of heterogeneous quality, relevance assessment of atlases becomes increasingly critical for multi-atlas-based image segmentation. However, there is no universally recognized best relevance metric and even a standard to compare amongst candidates remains elusive. This study, for the first time, designs a quantification to assess relevance metrics’ quality, based on a novel perspective of the metric as surrogate for inferring the inaccessible oracle geometric agreement. Methods: We first develop an inference model to relate surrogate metrics in image space to the underlying oracle relevance metric in segmentation label space, with a monotonically non-decreasing function subject tomore » random perturbations. Subsequently, we investigate model parameters to reveal key contributing factors to surrogates’ ability in prognosticating the oracle relevance value, for the specific task of atlas selection. Finally, we design an effective contract-to-noise ratio (eCNR) to quantify surrogates’ quality based on insights from these analyses and empirical observations. Results: The inference model was specialized to a linear function with normally distributed perturbations, with surrogate metric exemplified by several widely-used image similarity metrics, i.e., MSD/NCC/(N)MI. Surrogates’ behaviors in selecting the most relevant atlases were assessed under varying eCNR, showing that surrogates with high eCNR dominated those with low eCNR in retaining the most relevant atlases. In an end-to-end validation, NCC/(N)MI with eCNR of 0.12 compared to MSD with eCNR of 0.10 resulted in statistically better segmentation with mean DSC of about 0.85 and the first and third quartiles of (0.83, 0.89), compared to MSD with mean DSC of 0.84 and the first and third quartiles of (0.81, 0.89). Conclusion: The designed eCNR is capable of characterizing surrogate metrics’ quality in prognosticating the oracle relevance value. It has been demonstrated to be correlated with the performance of relevant atlas selection and ultimate label fusion.« less

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…

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…

Mississippi's New Forestry Best Management Practices Video

Treesearch

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,...

A comparison of video review and feedback device measurement of chest compressions quality during pediatric cardiopulmonary resuscitation.

PubMed

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.

Questionable validity of the catheter-associated urinary tract infection metric used for value-based purchasing.

PubMed

Calderon, Lindsay E; Kavanagh, Kevin T; Rice, Mara K

2015-10-01

Catheter-associated urinary tract infections (CAUTIs) occur in 290,000 US hospital patients annually, with an estimated cost of $290 million. Two different measurement systems are being used to track the US health care system's performance in lowering the rate of CAUTIs. Since 2010, the Agency for Healthcare Research and Quality (AHRQ) metric has shown a 28.2% decrease in CAUTI, whereas the Centers for Disease Control and Prevention metric has shown a 3%-6% increase in CAUTI since 2009. Differences in data acquisition and the definition of the denominator may explain this discrepancy. The AHRQ metric analyzes chart-audited data and reflects both catheter use and care. The Centers for Disease Control and Prevention metric analyzes self-reported data and primarily reflects catheter care. Because analysis of the AHRQ metric showed a progressive change in performance over time and the scientific literature supports the importance of catheter use in the prevention of CAUTI, it is suggested that risk-adjusted catheter-use data be incorporated into metrics that are used for determining facility performance and for value-based purchasing initiatives. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

The Use of Smart Glasses for Surgical Video Streaming.

PubMed

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.

Assessing the quality of restored images in optical long-baseline interferometry

NASA Astrophysics Data System (ADS)

Gomes, Nuno; Garcia, Paulo J. V.; Thiébaut, Éric

2017-03-01

Assessing the quality of aperture synthesis maps is relevant for benchmarking image reconstruction algorithms, for the scientific exploitation of data from optical long-baseline interferometers, and for the design/upgrade of new/existing interferometric imaging facilities. Although metrics have been proposed in these contexts, no systematic study has been conducted on the selection of a robust metric for quality assessment. This article addresses the question: what is the best metric to assess the quality of a reconstructed image? It starts by considering several metrics and selecting a few based on general properties. Then, a variety of image reconstruction cases are considered. The observational scenarios are phase closure and phase referencing at the Very Large Telescope Interferometer (VLTI), for a combination of two, three, four and six telescopes. End-to-end image reconstruction is accomplished with the MIRA software, and several merit functions are put to test. It is found that convolution by an effective point spread function is required for proper image quality assessment. The effective angular resolution of the images is superior to naive expectation based on the maximum frequency sampled by the array. This is due to the prior information used in the aperture synthesis algorithm and to the nature of the objects considered. The ℓ1-norm is the most robust of all considered metrics, because being linear it is less sensitive to image smoothing by high regularization levels. For the cases considered, this metric allows the implementation of automatic quality assessment of reconstructed images, with a performance similar to human selection.

Compressive Video Recovery Using Block Match Multi-Frame Motion Estimation Based on Single Pixel Cameras

PubMed Central

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

3D scene reconstruction based on multi-view distributed video coding in the Zernike domain for mobile applications

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.

Teaching Surgical Procedures with Movies: Tips for High-quality Video Clips.

PubMed

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.

Metric and morphological assessment of facial features: a study on three European populations.

PubMed

Ritz-Timme, S; Gabriel, P; Tutkuviene, J; Poppa, P; Obertová, Z; Gibelli, D; De Angelis, D; Ratnayake, M; Rizgeliene, R; Barkus, A; Cattaneo, C

2011-04-15

Identification from video surveillance systems is becoming more and more frequent in the forensic practice. In this field, different techniques have been improved such as height estimation and gait analysis. However, the most natural approach for identifying a person in everyday life is based on facial characteristics. Scientifically, faces can be described using morphological and metric assessment of facial features. The morphological approach is largely affected by the subjective opinion of the observer, which can be mitigated by the application of descriptive atlases. In addition, this approach requires one to investigate which are the most common and rare facial characteristics in different populations. For the metric approach further studies are necessary in order to point out possible metric differences within and between different populations. The acquisition of statistically adequate population data may provide useful information for the reconstruction of biological profiles of unidentified individuals, particularly concerning ethnic affiliation, and possibly also for personal identification. This study presents the results of the morphological and metric assessment of the head and face of 900 male subjects between 20 and 31 years from Italy, Germany and Lithuania. The evaluation of the morphological traits was performed using the DMV atlas with 43 pre-defined facial characteristics. The frequencies of the types of facial features were calculated for each population in order to establish the rarest characteristics which may be used for the purpose of a biological profile and consequently for personal identification. Metric analysis performed in vivo included 24 absolute measurements and 24 indices of the head and face, including body height and body weight. The comparison of the frequencies of morphological facial features showed many similarities between the samples from Germany, Italy and Lithuania. However, several characteristics were rare or significantly more or less common in one population compared to the other two. On the other hand, all measurements and indices, except for labial width and intercanthal-mouth index showed significant differences between the three populations. As far as comparisons with other samples are concerned, the three European Caucasian samples differed from North American Caucasian, African and Asian groups as concerns the frequency of the morphological traits and the mean values of the metric analysis. The metric and morphological data collected from three European populations may be useful for forensic purposes in the construction of biological profiles and in screening for personal identification. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

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.

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.

Retrieval evaluation and distance learning from perceived similarity between endomicroscopy videos.

PubMed

André, Barbara; Vercauteren, Tom; Buchner, Anna M; Wallace, Michael B; Ayache, Nicholas

2011-01-01

Evaluating content-based retrieval (CBR) is challenging because it requires an adequate ground-truth. When the available groundtruth is limited to textual metadata such as pathological classes, retrieval results can only be evaluated indirectly, for example in terms of classification performance. In this study we first present a tool to generate perceived similarity ground-truth that enables direct evaluation of endomicroscopic video retrieval. This tool uses a four-points Likert scale and collects subjective pairwise similarities perceived by multiple expert observers. We then evaluate against the generated ground-truth a previously developed dense bag-of-visual-words method for endomicroscopic video retrieval. Confirming the results of previous indirect evaluation based on classification, our direct evaluation shows that this method significantly outperforms several other state-of-the-art CBR methods. In a second step, we propose to improve the CBR method by learning an adjusted similarity metric from the perceived similarity ground-truth. By minimizing a margin-based cost function that differentiates similar and dissimilar video pairs, we learn a weight vector applied to the visual word signatures of videos. Using cross-validation, we demonstrate that the learned similarity distance is significantly better correlated with the perceived similarity than the original visual-word-based distance.

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.

Digital Elevation Model from Non-Metric Camera in Uas Compared with LIDAR Technology

NASA Astrophysics Data System (ADS)

Dayamit, O. M.; Pedro, M. F.; Ernesto, R. R.; Fernando, B. L.

2015-08-01

Digital Elevation Model (DEM) data as a representation of surface topography is highly demanded for use in spatial analysis and modelling. Aimed to that issue many methods of acquisition data and process it are developed, from traditional surveying until modern technology like LIDAR. On the other hands, in a past four year the development of Unamend Aerial System (UAS) aimed to Geomatic bring us the possibility to acquire data about surface by non-metric digital camera on board in a short time with good quality for some analysis. Data collectors have attracted tremendous attention on UAS due to possibility of the determination of volume changes over time, monitoring of the breakwaters, hydrological modelling including flood simulation, drainage networks, among others whose support in DEM for proper analysis. The DEM quality is considered as a combination of DEM accuracy and DEM suitability so; this paper is aimed to analyse the quality of the DEM from non-metric digital camera on UAS compared with a DEM from LIDAR corresponding to same geographic space covering 4 km2 in Artemisa province, Cuba. This area is in a frame of urban planning whose need to know the topographic characteristics in order to analyse hydrology behaviour and decide the best place for make roads, building and so on. Base on LIDAR technology is still more accurate method, it offer us a pattern for test DEM from non-metric digital camera on UAS, whose are much more flexible and bring a solution for many applications whose needs DEM of detail.

The Quality of Open-Access Video-Based Orthopaedic Instructional Content for the Shoulder Physical Exam is Inconsistent.

PubMed

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.

Video quality of 3G videophones for telephone cardiopulmonary resuscitation.

PubMed

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.

Does Multimedia Education with 3D Animation Impact Quality and Duration of Urologists' Interactions with their Prostate Cancer Patients?

PubMed

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.

Resource optimized TTSH-URA for multimedia stream authentication in swallowable-capsule-based wireless body sensor networks.

PubMed

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.

Instructional analysis of lecture video recordings and its application for quality improvement of medical lectures.

PubMed

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.

App Usage Factor: A Simple Metric to Compare the Population Impact of Mobile Medical Apps

PubMed Central

Wyatt, Jeremy C

2015-01-01

Background One factor when assessing the quality of mobile apps is quantifying the impact of a given app on a population. There is currently no metric which can be used to compare the population impact of a mobile app across different health care disciplines. Objective The objective of this study is to create a novel metric to characterize the impact of a mobile app on a population. Methods We developed the simple novel metric, app usage factor (AUF), defined as the logarithm of the product of the number of active users of a mobile app with the median number of daily uses of the app. The behavior of this metric was modeled using simulated modeling in Python, a general-purpose programming language. Three simulations were conducted to explore the temporal and numerical stability of our metric and a simulated app ecosystem model using a simulated dataset of 20,000 apps. Results Simulations confirmed the metric was stable between predicted usage limits and remained stable at extremes of these limits. Analysis of a simulated dataset of 20,000 apps calculated an average value for the app usage factor of 4.90 (SD 0.78). A temporal simulation showed that the metric remained stable over time and suitable limits for its use were identified. Conclusions A key component when assessing app risk and potential harm is understanding the potential population impact of each mobile app. Our metric has many potential uses for a wide range of stakeholders in the app ecosystem, including users, regulators, developers, and health care professionals. Furthermore, this metric forms part of the overall estimate of risk and potential for harm or benefit posed by a mobile medical app. We identify the merits and limitations of this metric, as well as potential avenues for future validation and research. PMID:26290093

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.

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.

Calculation and use of an environment's characteristic software metric set

NASA Technical Reports Server (NTRS)

Basili, Victor R.; Selby, Richard W., Jr.

1985-01-01

Since both cost/quality and production environments differ, this study presents an approach for customizing a characteristic set of software metrics to an environment. The approach is applied in the Software Engineering Laboratory (SEL), a NASA Goddard production environment, to 49 candidate process and product metrics of 652 modules from six (51,000 to 112,000 lines) projects. For this particular environment, the method yielded the characteristic metric set (source lines, fault correction effort per executable statement, design effort, code effort, number of I/O parameters, number of versions). The uses examined for a characteristic metric set include forecasting the effort for development, modification, and fault correction of modules based on historical data.

Clustered-dot halftoning with direct binary search.

PubMed

Goyal, Puneet; Gupta, Madhur; Staelin, Carl; Fischer, Mani; Shacham, Omri; Allebach, Jan P

2013-02-01

In this paper, we present a new algorithm for aperiodic clustered-dot halftoning based on direct binary search (DBS). The DBS optimization framework has been modified for designing clustered-dot texture, by using filters with different sizes in the initialization and update steps of the algorithm. Following an intuitive explanation of how the clustered-dot texture results from this modified framework, we derive a closed-form cost metric which, when minimized, equivalently generates stochastic clustered-dot texture. An analysis of the cost metric and its influence on the texture quality is presented, which is followed by a modification to the cost metric to reduce computational cost and to make it more suitable for screen design.

Modified fuzzy c-means applied to a Bragg grating-based spectral imager for material clustering

NASA Astrophysics Data System (ADS)

Rodríguez, Aida; Nieves, Juan Luis; Valero, Eva; Garrote, Estíbaliz; Hernández-Andrés, Javier; Romero, Javier

2012-01-01

We have modified the Fuzzy C-Means algorithm for an application related to segmentation of hyperspectral images. Classical fuzzy c-means algorithm uses Euclidean distance for computing sample membership to each cluster. We have introduced a different distance metric, Spectral Similarity Value (SSV), in order to have a more convenient similarity measure for reflectance information. SSV distance metric considers both magnitude difference (by the use of Euclidean distance) and spectral shape (by the use of Pearson correlation). Experiments confirmed that the introduction of this metric improves the quality of hyperspectral image segmentation, creating spectrally more dense clusters and increasing the number of correctly classified pixels.

YouTube videos as a source of medical information during the Ebola hemorrhagic fever epidemic.

PubMed

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.

Veterinary students' usage and perception of video teaching resources.

PubMed

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.

Evaluation of ride quality prediction methods for operational military helicopters

NASA Technical Reports Server (NTRS)

Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

1984-01-01

The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots' discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

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.

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.

Picturing Video

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.

Integer-Linear-Programing Optimization in Scalable Video Multicast with Adaptive Modulation and Coding in Wireless Networks

PubMed Central

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 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…

Sound quality evaluation of air conditioning sound rating metric

NASA Astrophysics Data System (ADS)

Hodgdon, Kathleen K.; Peters, Jonathan A.; Burkhardt, Russell C.; Atchley, Anthony A.; Blood, Ingrid M.

2003-10-01

A product's success can depend on its acoustic signature as much as on the product's performance. The consumer's perception can strongly influence their satisfaction with and confidence in the product. A metric that can rate the content of the spectrum, and predict its consumer preference, is a valuable tool for manufacturers. The current method of assessing acoustic signatures from residential air conditioning units is defined in the Air Conditioning and Refrigeration Institute (ARI 270) 1995 Standard for Sound Rating of Outdoor Unitary Equipment. The ARI 270 metric, and modified versions of that metric, were implemented in software with the flexibility to modify the features applied. Numerous product signatures were analyzed to generate a set of synthesized spectra that targeted spectral configurations that challenged the metric's abilities. A subjective jury evaluation was conducted to establish the consumer preference for those spectra. Statistical correlations were conducted to assess the degree of relationship between the subjective preferences and the various metric calculations. Recommendations were made for modifications to improve the current metric's ability to predict subjective preference. [Research supported by the Air Conditioning and Refrigeration Institute.

Adaptive distance metric learning for diffusion tensor image segmentation.

PubMed

Kong, Youyong; Wang, Defeng; Shi, Lin; Hui, Steve C N; Chu, Winnie C W

2014-01-01

High quality segmentation of diffusion tensor images (DTI) is of key interest in biomedical research and clinical application. In previous studies, most efforts have been made to construct predefined metrics for different DTI segmentation tasks. These methods require adequate prior knowledge and tuning parameters. To overcome these disadvantages, we proposed to automatically learn an adaptive distance metric by a graph based semi-supervised learning model for DTI segmentation. An original discriminative distance vector was first formulated by combining both geometry and orientation distances derived from diffusion tensors. The kernel metric over the original distance and labels of all voxels were then simultaneously optimized in a graph based semi-supervised learning approach. Finally, the optimization task was efficiently solved with an iterative gradient descent method to achieve the optimal solution. With our approach, an adaptive distance metric could be available for each specific segmentation task. Experiments on synthetic and real brain DTI datasets were performed to demonstrate the effectiveness and robustness of the proposed distance metric learning approach. The performance of our approach was compared with three classical metrics in the graph based semi-supervised learning framework.

Gaze-Aware Streaming Solutions for the Next Generation of Mobile VR Experiences.

PubMed

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.

Staff acceptance of video monitoring for coordination: a video system to support perioperative situation awareness.

PubMed

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.

Adaptive Distance Metric Learning for Diffusion Tensor Image Segmentation

PubMed Central

Kong, Youyong; Wang, Defeng; Shi, Lin; Hui, Steve C. N.; Chu, Winnie C. W.

2014-01-01

High quality segmentation of diffusion tensor images (DTI) is of key interest in biomedical research and clinical application. In previous studies, most efforts have been made to construct predefined metrics for different DTI segmentation tasks. These methods require adequate prior knowledge and tuning parameters. To overcome these disadvantages, we proposed to automatically learn an adaptive distance metric by a graph based semi-supervised learning model for DTI segmentation. An original discriminative distance vector was first formulated by combining both geometry and orientation distances derived from diffusion tensors. The kernel metric over the original distance and labels of all voxels were then simultaneously optimized in a graph based semi-supervised learning approach. Finally, the optimization task was efficiently solved with an iterative gradient descent method to achieve the optimal solution. With our approach, an adaptive distance metric could be available for each specific segmentation task. Experiments on synthetic and real brain DTI datasets were performed to demonstrate the effectiveness and robustness of the proposed distance metric learning approach. The performance of our approach was compared with three classical metrics in the graph based semi-supervised learning framework. PMID:24651858

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.

Teaching Surgical Procedures with Movies: Tips for High-quality Video Clips

PubMed Central

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

Task-based detectability comparison of exponential transformation of free-response operating characteristic (EFROC) curve and channelized Hotelling observer (CHO)

NASA Astrophysics Data System (ADS)

Khobragade, P.; Fan, Jiahua; Rupcich, Franco; Crotty, Dominic J.; Gilat Schmidt, Taly

2016-03-01

This study quantitatively evaluated the performance of the exponential transformation of the free-response operating characteristic curve (EFROC) metric, with the Channelized Hotelling Observer (CHO) as a reference. The CHO has been used for image quality assessment of reconstruction algorithms and imaging systems and often it is applied to study the signal-location-known cases. The CHO also requires a large set of images to estimate the covariance matrix. In terms of clinical applications, this assumption and requirement may be unrealistic. The newly developed location-unknown EFROC detectability metric is estimated from the confidence scores reported by a model observer. Unlike the CHO, EFROC does not require a channelization step and is a non-parametric detectability metric. There are few quantitative studies available on application of the EFROC metric, most of which are based on simulation data. This study investigated the EFROC metric using experimental CT data. A phantom with four low contrast objects: 3mm (14 HU), 5mm (7HU), 7mm (5 HU) and 10 mm (3 HU) was scanned at dose levels ranging from 25 mAs to 270 mAs and reconstructed using filtered backprojection. The area under the curve values for CHO (AUC) and EFROC (AFE) were plotted with respect to different dose levels. The number of images required to estimate the non-parametric AFE metric was calculated for varying tasks and found to be less than the number of images required for parametric CHO estimation. The AFE metric was found to be more sensitive to changes in dose than the CHO metric. This increased sensitivity and the assumption of unknown signal location may be useful for investigating and optimizing CT imaging methods. Future work is required to validate the AFE metric against human observers.

The influence of motion quality on responses towards video playback stimuli.

PubMed

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.

Transmission of live laparoscopic surgery over the Internet2.

PubMed

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.

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, 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...

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.

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...

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…

Effects of Video-Feedback Interaction Training for Professional Caregivers of Children and Adults with Visual and Intellectual Disabilities

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…

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...

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.

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.

A GPS Phase-Locked Loop Performance Metric Based on the Phase Discriminator Output

PubMed Central

Stevanovic, Stefan; Pervan, Boris

2018-01-01

We propose a novel GPS phase-lock loop (PLL) performance metric based on the standard deviation of tracking error (defined as the discriminator’s estimate of the true phase error), and explain its advantages over the popular phase jitter metric using theory, numerical simulation, and experimental results. We derive an augmented GPS phase-lock loop (PLL) linear model, which includes the effect of coherent averaging, to be used in conjunction with this proposed metric. The augmented linear model allows more accurate calculation of tracking error standard deviation in the presence of additive white Gaussian noise (AWGN) as compared to traditional linear models. The standard deviation of tracking error, with a threshold corresponding to half of the arctangent discriminator pull-in region, is shown to be a more reliable/robust measure of PLL performance under interference conditions than the phase jitter metric. In addition, the augmented linear model is shown to be valid up until this threshold, which facilitates efficient performance prediction, so that time-consuming direct simulations and costly experimental testing can be reserved for PLL designs that are much more likely to be successful. The effect of varying receiver reference oscillator quality on the tracking error metric is also considered. PMID:29351250

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.

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.

Quality metrics for sensor images

NASA Technical Reports Server (NTRS)

Ahumada, AL

1993-01-01

Methods are needed for evaluating the quality of augmented visual displays (AVID). Computational quality metrics will help summarize, interpolate, and extrapolate the results of human performance tests with displays. The FLM Vision group at NASA Ames has been developing computational models of visual processing and using them to develop computational metrics for similar problems. For example, display modeling systems use metrics for comparing proposed displays, halftoning optimizing methods use metrics to evaluate the difference between the halftone and the original, and image compression methods minimize the predicted visibility of compression artifacts. The visual discrimination models take as input two arbitrary images A and B and compute an estimate of the probability that a human observer will report that A is different from B. If A is an image that one desires to display and B is the actual displayed image, such an estimate can be regarded as an image quality metric reflecting how well B approximates A. There are additional complexities associated with the problem of evaluating the quality of radar and IR enhanced displays for AVID tasks. One important problem is the question of whether intruding obstacles are detectable in such displays. Although the discrimination model can handle detection situations by making B the original image A plus the intrusion, this detection model makes the inappropriate assumption that the observer knows where the intrusion will be. Effects of signal uncertainty need to be added to our models. A pilot needs to make decisions rapidly. The models need to predict not just the probability of a correct decision, but the probability of a correct decision by the time the decision needs to be made. That is, the models need to predict latency as well as accuracy. Luce and Green have generated models for auditory detection latencies. Similar models are needed for visual detection. Most image quality models are designed for static imagery. Watson has been developing a general spatial-temporal vision model to optimize video compression techniques. These models need to be adapted and calibrated for AVID applications.

Quantitative evaluation for accumulative calibration error and video-CT registration errors in electromagnetic-tracked endoscopy.

PubMed

Liu, Sheena Xin; Gutiérrez, Luis F; Stanton, Doug

2011-05-01

Electromagnetic (EM)-guided endoscopy has demonstrated its value in minimally invasive interventions. Accuracy evaluation of the system is of paramount importance to clinical applications. Previously, a number of researchers have reported the results of calibrating the EM-guided endoscope; however, the accumulated errors of an integrated system, which ultimately reflect intra-operative performance, have not been characterized. To fill this vacancy, we propose a novel system to perform this evaluation and use a 3D metric to reflect the intra-operative procedural accuracy. This paper first presents a portable design and a method for calibration of an electromagnetic (EM)-tracked endoscopy system. An evaluation scheme is then described that uses the calibration results and EM-CT registration to enable real-time data fusion between CT and endoscopic video images. We present quantitative evaluation results for estimating the accuracy of this system using eight internal fiducials as the targets on an anatomical phantom: the error is obtained by comparing the positions of these targets in the CT space, EM space and endoscopy image space. To obtain 3D error estimation, the 3D locations of the targets in the endoscopy image space are reconstructed from stereo views of the EM-tracked monocular endoscope. Thus, the accumulated errors are evaluated in a controlled environment, where the ground truth information is present and systematic performance (including the calibration error) can be assessed. We obtain the mean in-plane error to be on the order of 2 pixels. To evaluate the data integration performance for virtual navigation, target video-CT registration error (TRE) is measured as the 3D Euclidean distance between the 3D-reconstructed targets of endoscopy video images and the targets identified in CT. The 3D error (TRE) encapsulates EM-CT registration error, EM-tracking error, fiducial localization error, and optical-EM calibration error. We present in this paper our calibration method and a virtual navigation evaluation system for quantifying the overall errors of the intra-operative data integration. We believe this phantom not only offers us good insights to understand the systematic errors encountered in all phases of an EM-tracked endoscopy procedure but also can provide quality control of laboratory experiments for endoscopic procedures before the experiments are transferred from the laboratory to human subjects.

Profiles of the evaluators: impact of psychographic variables on the consumer-oriented quality assessment of mobile television

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.

Comparison of macroinvertebrate-derived stream quality metrics between snag and riffle habitats

USGS Publications Warehouse

Stepenuck, K.F.; Crunkilton, R.L.; Bozek, Michael A.; Wang, L.

2008-01-01

We compared benthic macroinvertebrate assemblage structure at snag and riffle habitats in 43 Wisconsin streams across a range of watershed urbanization using a variety of stream quality metrics. Discriminant analysis indicated that dominant taxa at riffles and snags differed; Hydropsychid caddisflies (Hydropsyche betteni and Cheumatopsyche spp.) and elmid beetles (Optioservus spp. and Stenemlis spp.) typified riffles, whereas isopods (Asellus intermedius) and amphipods (Hyalella azteca and Gammarus pseudolimnaeus) predominated in snags. Analysis of covariance indicated that samples from snag and riffle habitats differed significantly in their response to the urbanization gradient for the Hilsenhoff biotic index (BI), Shannon's diversity index, and percent of filterers, shredders, and pollution intolerant Ephemeroptera, Plecoptera, and Trichoptera (EPT) at each stream site (p ??? 0.10). These differences suggest that although macroinvertebrate assemblages present in either habitat type are sensitive to detecting the effects of urbanization, metrics derived from different habitats should not be intermixed when assessing stream quality through biomonitoring. This can be a limitation to resource managers who wish to compare water quality among streams where the same habitat type is not available at all stream locations, or where a specific habitat type (i.e., a riffle) is required to determine a metric value (i.e., BI). To account for differences in stream quality at sites lacking riffle habitat, snag-derived metric values can be adjusted based on those obtained from riffles that have been exposed to the same level of urbanization. Comparison of nonlinear regression equations that related stream quality metric values from the two habitat types to percent watershed urbanization indicated that snag habitats had on average 30.2 fewer percent EPT individuals, a lower diversity index value than riffles, and a BI value of 0.29 greater than riffles. ?? 2008 American Water Resources Association.

Sensor fusion and augmented reality with the SAFIRE system

NASA Astrophysics Data System (ADS)

Saponaro, Philip; Treible, Wayne; Phelan, Brian; Sherbondy, Kelly; Kambhamettu, Chandra

2018-04-01

The Spectrally Agile Frequency-Incrementing Reconfigurable (SAFIRE) mobile radar system was developed and exercised at an arid U.S. test site. The system can detect hidden target using radar, a global positioning system (GPS), dual stereo color cameras, and dual stereo thermal cameras. An Augmented Reality (AR) software interface allows the user to see a single fused video stream containing the SAR, color, and thermal imagery. The stereo sensors allow the AR system to display both fused 2D imagery and 3D metric reconstructions, where the user can "fly" around the 3D model and switch between the modalities.

Transfusion rate as a quality metric: is blood conservation a learnable skill?

PubMed

Paone, Gaetano; Brewer, Robert; Likosky, Donald S; Theurer, Patricia F; Bell, Gail F; Cogan, Chad M; Prager, Richard L

2013-10-01

Between January 2008 and December 2012, a multicenter quality collaborative initiated a focus on blood conservation as a quality metric, with educational presentations and quarterly reporting of institutional-level perioperative transfusion rates and outcomes. This prospective cohort study was undertaken to determine the effect of that initiative on transfusion rates after isolated coronary artery bypass grafting (CABG). Between January 1, 2008, and December 31, 2012, 30,271 patients underwent isolated CABG in Michigan. Evaluated were annual crude and adjusted trends in overall transfusion rates for red blood cells (RBCs), fresh frozen plasma (FFP), and platelets, and in operative death. Transfusion rates continuously decreased for all blood products. RBC use decreased from 56.4% in 2008 (baseline) to 38.3% in 2012, FFP use decreased from 14.8% to 9.1%, and platelet use decreased from 20.5% to 13.4% (ptrend < 0.001 for all). A significant reduction occurred in deep sternal wound infection, reoperation for bleeding, renal failure, prolonged ventilation, initial ventilator time, and intensive care unit duration. The percentage of patients discharged home significantly increased (ptrend < 0.001). Mortality rates did not differ significantly (ptrend = 0.11). In a multicenter quality collaborative, increased attention to transfusion-related outcomes and blood conservation techniques, coincident with regular reporting and review of perioperative transfusion rates as a quality metric, was associated with a significant decrease in blood product utilization. These reductions were concurrent with significant improvement in most perioperative outcomes. This intervention was also safe, as it was not associated with any increases in mortality. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

An Evaluation of Educational Neurological Eye Movement Disorder Videos Posted on Internet Video Sharing Sites.

PubMed

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.

SU-G-BRB-16: Vulnerabilities in the Gamma Metric

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neal, B; Siebers, J

Purpose: To explore vulnerabilities in the gamma index metric that undermine its wide use as a radiation therapy quality assurance tool. Methods: 2D test field pairs (images) are created specifically to achieve high gamma passing rates, but to also include gross errors by exploiting the distance-to-agreement and percent-passing components of the metric. The first set has no requirement of clinical practicality, but is intended to expose vulnerabilities. The second set exposes clinically realistic vulnerabilities. To circumvent limitations inherent to user-specific tuning of prediction algorithms to match measurements, digital test cases are manually constructed, thereby mimicking high-quality image prediction. Results: Withmore » a 3 mm distance-to-agreement metric, changing field size by ±6 mm results in a gamma passing rate over 99%. For a uniform field, a lattice of passing points spaced 5 mm apart results in a passing rate of 100%. Exploiting the percent-passing component, a 10×10 cm{sup 2} field can have a 95% passing rate when an 8 cm{sup 2}=2.8×2.8 cm{sup 2} highly out-of-tolerance (e.g. zero dose) square is missing from the comparison image. For clinically realistic vulnerabilities, an arc plan for which a 2D image is created can have a >95% passing rate solely due to agreement in the lateral spillage, with the failing 5% in the critical target region. A field with an integrated boost (e.g whole brain plus small metastases) could neglect the metastases entirely, yet still pass with a 95% threshold. All the failure modes described would be visually apparent on a gamma-map image. Conclusion: The %gamma<1 metric has significant vulnerabilities. High passing rates can obscure critical faults in hypothetical and delivered radiation doses. Great caution should be used with gamma as a QA metric; users should inspect the gamma-map. Visual analysis of gamma-maps may be impractical for cine acquisition.« less

Development of new UV-I. I. Cerenkov Viewing Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuribara, Masayuki; Nemoto, Koshichi

1994-02-01

The Cerenkov glow images from boiling-water reactors (BWR) and pressurized-water reactors (PWR) irradiated fuel assemblies are generally used for inspections. However, sometimes it is difficult or impossible to identify the image by the conventional Cerenkov Viewing Device (CVD), because of the long cooling time and/or low burnup. Now a new UV-I.I. (Ultra-Violet light Image Intensifier) CVD has been developed, which can detect the very weak Cerenkov glow from spent fuel assemblies. As this new device uses the newly developed proximity focused type UV-I.I., Cerenkov photons are used efficiently, producing better quality Cerenkov glow images. Moreover, since the image is convertedmore » to a video signal, it is easy to improve the signal to noise ratio (S/N) by an image processor. The new CVD was tested at BWR and PWR power plants in Japan, with fuel burnups ranging from 6,200--33,000 MWD/MTU (megawatt days per metric ton of uranium) and cooling times ranging from 370 to 6,200 d. The tests showed that the new CVD is superior to the conventional STA/CRIEPI CVD, and could detect very feeble Cerenkov glow images using an image processor.« less

Measuring perceived video quality of MPEG enhancement by people with impaired vision

PubMed Central

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

An Opportunistic Routing Mechanism Combined with Long-Term and Short-Term Metrics for WMN

PubMed Central

Piao, Xianglan; Qiu, Tie

2014-01-01

WMN (wireless mesh network) is a useful wireless multihop network with tremendous research value. The routing strategy decides the performance of network and the quality of transmission. A good routing algorithm will use the whole bandwidth of network and assure the quality of service of traffic. Since the routing metric ETX (expected transmission count) does not assure good quality of wireless links, to improve the routing performance, an opportunistic routing mechanism combined with long-term and short-term metrics for WMN based on OLSR (optimized link state routing) and ETX is proposed in this paper. This mechanism always chooses the highest throughput links to improve the performance of routing over WMN and then reduces the energy consumption of mesh routers. The simulations and analyses show that the opportunistic routing mechanism is better than the mechanism with the metric of ETX. PMID:25250379

Evaluation of ride quality prediction methods for helicopter interior noise and vibration environments

NASA Technical Reports Server (NTRS)

Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

1984-01-01

The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

High-grade video compression of echocardiographic studies: a multicenter validation study of selected motion pictures expert groups (MPEG)-4 algorithms.

PubMed

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.

Quality of pharmaceutical care at the pharmacy counter: patients' experiences versus video observation.

PubMed

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.

A new method for digital video documentation in surgical procedures and minimally invasive surgery.

PubMed

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.

Mobile videoconferencing for enhanced emergency medical communication - a shot in the dark or a walk in the park? ‒‒ A simulation study.

PubMed

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.

An opportunistic routing mechanism combined with long-term and short-term metrics for WMN.

PubMed

Sun, Weifeng; Wang, Haotian; Piao, Xianglan; Qiu, Tie

2014-01-01

WMN (wireless mesh network) is a useful wireless multihop network with tremendous research value. The routing strategy decides the performance of network and the quality of transmission. A good routing algorithm will use the whole bandwidth of network and assure the quality of service of traffic. Since the routing metric ETX (expected transmission count) does not assure good quality of wireless links, to improve the routing performance, an opportunistic routing mechanism combined with long-term and short-term metrics for WMN based on OLSR (optimized link state routing) and ETX is proposed in this paper. This mechanism always chooses the highest throughput links to improve the performance of routing over WMN and then reduces the energy consumption of mesh routers. The simulations and analyses show that the opportunistic routing mechanism is better than the mechanism with the metric of ETX.

Optimal colour quality of LED clusters based on memory colours.

PubMed

Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

2011-03-28

The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant.

Estimating Depolarization with the Jones Matrix Quality Factor

NASA Astrophysics Data System (ADS)

Hilfiker, James N.; Hale, Jeffrey S.; Herzinger, Craig M.; Tiwald, Tom; Hong, Nina; Schöche, Stefan; Arwin, Hans

2017-11-01

Mueller matrix (MM) measurements offer the ability to quantify the depolarization capability of a sample. Depolarization can be estimated using terms such as the depolarization index or the average degree of polarization. However, these calculations require measurement of the complete MM. We propose an alternate depolarization metric, termed the Jones matrix quality factor, QJM, which does not require the complete MM. This metric provides a measure of how close, in a least-squares sense, a Jones matrix can be found to the measured Mueller matrix. We demonstrate and compare the use of QJM to other traditional calculations of depolarization for both isotropic and anisotropic depolarizing samples; including non-uniform coatings, anisotropic crystal substrates, and beetle cuticles that exhibit both depolarization and circular diattenuation.

Converting laserdisc video to digital video: a demonstration project using brain animations.

PubMed

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.

Improving Software Quality and Management Through Use of Service Level Agreements

DTIC Science & Technology

2005-03-01

many who believe that the quality of the development process is the best predictor of software product quality. ( Fenton ) Repeatable software processes...reduced errors per KLOC for small projects ( Fenton ), and the quality management metric (QMM) (Machniak, Osmundson). There are also numerous IEEE 14...attention to cosmetic user interface issues and any problems that may arise with the prototype. (Sawyer) The validation process is also another check

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.

Video Communication Program.

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…

Video image processing greatly enhances contrast, quality, and speed in polarization-based microscopy

PubMed Central

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

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.

Analysis of Open Education Service Quality with the Descriptive-Quantitative Approach

ERIC Educational Resources Information Center

Priyogi, Bilih; Santoso, Harry B.; Berliyanto; Hasibuan, Zainal A.

2017-01-01

The concept of Open Education (OE) is based on the philosophy of e-Learning which aims to provide learning environment anywhere, anytime, and for anyone. One of the main issue in the development of OE services is the availability of the quality assurance mechanism. This study proposes a metric for measuring the quality of OE service. Based on…

Measuring Balance Across Multiple Radar Receiver Channels.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doerry, Armin W.; Bickel, Douglas L.

When radar receivers employ multiple channels, the general intent is for the receive channels to be as alike as possible, if not as ideal as possible. This is usually done via prudent hardware design, supplemented by system calibration. Towards this end, we require a quality metric for ascertaining the goodness of a radar channel, and the degree of match to sibling channels. We propose a relevant and useable metric to do just that. Acknowledgements This report was the result of an unfunded research and development activity.

Quality of audio-assisted versus video-assisted dispatcher-instructed bystander cardiopulmonary resuscitation: A systematic review and meta-analysis.

PubMed

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.

EVALUATION OF METRIC PRECISION FOR A RIPARIAN FOREST SURVEY

EPA Science Inventory

This paper evaluates the performance of a protocol to monitor riparian forests in western Oregon based on the quality of the data obtained from a recent field survey. Precision and accuracy are the criteria used to determine the quality of 19 field metrics. The field survey con...

Automated Video-Based Analysis of Contractility and Calcium Flux in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Cultured over Different Spatial Scales.

PubMed

Huebsch, Nathaniel; Loskill, Peter; Mandegar, Mohammad A; Marks, Natalie C; Sheehan, Alice S; Ma, Zhen; Mathur, Anurag; Nguyen, Trieu N; Yoo, Jennie C; Judge, Luke M; Spencer, C Ian; Chukka, Anand C; Russell, Caitlin R; So, Po-Lin; Conklin, Bruce R; Healy, Kevin E

2015-05-01

Contractile motion is the simplest metric of cardiomyocyte health in vitro, but unbiased quantification is challenging. We describe a rapid automated method, requiring only standard video microscopy, to analyze the contractility of human-induced pluripotent stem cell-derived cardiomyocytes (iPS-CM). New algorithms for generating and filtering motion vectors combined with a newly developed isogenic iPSC line harboring genetically encoded calcium indicator, GCaMP6f, allow simultaneous user-independent measurement and analysis of the coupling between calcium flux and contractility. The relative performance of these algorithms, in terms of improving signal to noise, was tested. Applying these algorithms allowed analysis of contractility in iPS-CM cultured over multiple spatial scales from single cells to three-dimensional constructs. This open source software was validated with analysis of isoproterenol response in these cells, and can be applied in future studies comparing the drug responsiveness of iPS-CM cultured in different microenvironments in the context of tissue engineering.

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)

Automated Video-Based Analysis of Contractility and Calcium Flux in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Cultured over Different Spatial Scales

PubMed Central

Huebsch, Nathaniel; Loskill, Peter; Mandegar, Mohammad A.; Marks, Natalie C.; Sheehan, Alice S.; Ma, Zhen; Mathur, Anurag; Nguyen, Trieu N.; Yoo, Jennie C.; Judge, Luke M.; Spencer, C. Ian; Chukka, Anand C.; Russell, Caitlin R.; So, Po-Lin

2015-01-01

Contractile motion is the simplest metric of cardiomyocyte health in vitro, but unbiased quantification is challenging. We describe a rapid automated method, requiring only standard video microscopy, to analyze the contractility of human-induced pluripotent stem cell-derived cardiomyocytes (iPS-CM). New algorithms for generating and filtering motion vectors combined with a newly developed isogenic iPSC line harboring genetically encoded calcium indicator, GCaMP6f, allow simultaneous user-independent measurement and analysis of the coupling between calcium flux and contractility. The relative performance of these algorithms, in terms of improving signal to noise, was tested. Applying these algorithms allowed analysis of contractility in iPS-CM cultured over multiple spatial scales from single cells to three-dimensional constructs. This open source software was validated with analysis of isoproterenol response in these cells, and can be applied in future studies comparing the drug responsiveness of iPS-CM cultured in different microenvironments in the context of tissue engineering. PMID:25333967

Video Compression

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.

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.

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.

Open-source telemedicine platform for wireless medical video communication.

PubMed

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.

Evaluation of image deblurring methods via a classification metric

NASA Astrophysics Data System (ADS)

Perrone, Daniele; Humphreys, David; Lamb, Robert A.; Favaro, Paolo

2012-09-01

The performance of single image deblurring algorithms is typically evaluated via a certain discrepancy measure between the reconstructed image and the ideal sharp image. The choice of metric, however, has been a source of debate and has also led to alternative metrics based on human visual perception. While fixed metrics may fail to capture some small but visible artifacts, perception-based metrics may favor reconstructions with artifacts that are visually pleasant. To overcome these limitations, we propose to assess the quality of reconstructed images via a task-driven metric. In this paper we consider object classification as the task and therefore use the rate of classification as the metric to measure deblurring performance. In our evaluation we use data with different types of blur in two cases: Optical Character Recognition (OCR), where the goal is to recognise characters in a black and white image, and object classification with no restrictions on pose, illumination and orientation. Finally, we show how off-the-shelf classification algorithms benefit from working with deblurred images.

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.

Live versus Video Observations: Comparing the Reliability and Validity of Two Methods of Assessing Classroom Quality

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…

Twelve tips for reducing production time and increasing long-term usability of instructional video.

PubMed

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.

Veterinary students' usage and perception of video teaching resources

PubMed Central

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

Feasibility Study of Utilization of Action Camera, GoPro Hero 4, Google Glass, and Panasonic HX-A100 in Spine Surgery.

PubMed

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.

Concept-oriented indexing of video databases: toward semantic sensitive retrieval and browsing.

PubMed

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.

Robotic Telesurgery Research

DTIC Science & Technology

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

Examining the Quality of Preservice Science Teachers' Written Reflections When Using Video Recordings, Audio Recordings, and Memories of a Teaching Event

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…

Active Video Games as a Training Tool for Individuals With Chronic Respiratory Diseases: A SYSTEMATIC REVIEW.

PubMed

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.

Optimization of Regression Models of Experimental Data Using Confirmation Points

NASA Technical Reports Server (NTRS)

Ulbrich, N.

2010-01-01

A new search metric is discussed that may be used to better assess the predictive capability of different math term combinations during the optimization of a regression model of experimental data. The new search metric can be determined for each tested math term combination if the given experimental data set is split into two subsets. The first subset consists of data points that are only used to determine the coefficients of the regression model. The second subset consists of confirmation points that are exclusively used to test the regression model. The new search metric value is assigned after comparing two values that describe the quality of the fit of each subset. The first value is the standard deviation of the PRESS residuals of the data points. The second value is the standard deviation of the response residuals of the confirmation points. The greater of the two values is used as the new search metric value. This choice guarantees that both standard deviations are always less or equal to the value that is used during the optimization. Experimental data from the calibration of a wind tunnel strain-gage balance is used to illustrate the application of the new search metric. The new search metric ultimately generates an optimized regression model that was already tested at regression model independent confirmation points before it is ever used to predict an unknown response from a set of regressors.

Eye of the Beholder: Stage Entrance Behavior and Facial Expression Affect Continuous Quality Ratings in Music Performance

PubMed Central

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

Evaluation of color mapping algorithms in different color spaces

NASA Astrophysics Data System (ADS)

Bronner, Timothée.-Florian; Boitard, Ronan; Pourazad, Mahsa T.; Nasiopoulos, Panos; Ebrahimi, Touradj

2016-09-01

The color gamut supported by current commercial displays is only a subset of the full spectrum of colors visible by the human eye. In High-Definition (HD) television technology, the scope of the supported colors covers 35.9% of the full visible gamut. For comparison, Ultra High-Definition (UHD) television, which is currently being deployed on the market, extends this range to 75.8%. However, when reproducing content with a wider color gamut than that of a television, typically UHD content on HD television, some original color information may lie outside the reproduction capabilities of the television. Efficient gamut mapping techniques are required in order to fit the colors of any source content into the gamut of a given display. The goal of gamut mapping is to minimize the distortion, in terms of perceptual quality, when converting video from one color gamut to another. It is assumed that the efficiency of gamut mapping depends on the color space in which it is computed. In this article, we evaluate 14 gamut mapping techniques, 12 combinations of two projection methods across six color spaces as well as R'G'B' Clipping and wrong gamut interpretation. Objective results, using the CIEDE2000 metric, show that the R'G'B' Clipping is slightly outperformed by only one combination of color space and projection method. However, analysis of images shows that R'G'B' Clipping can result in loss of contrast in highly saturated images, greatly impairing the quality of the mapped image.

Quality measurement for rhinosinusitis: a review from the Quality Improvement Committee of the American Rhinologic Society.

PubMed

Rudmik, Luke; Mattos, Jose; Schneider, John; Manes, Peter R; Stokken, Janalee K; Lee, Jivianne; Higgins, Thomas S; Schlosser, Rodney J; Reh, Douglas D; Setzen, Michael; Soler, Zachary M

2017-09-01

Measuring quality outcomes is an important prerequisite to improve quality of care. Rhinosinusitis represents a high value target to improve quality of care because it has a high prevalence of disease, large economic burden, and large practice variation. In this study we review the current state of quality measurement for management of both acute (ARS) and chronic rhinosinusitis (CRS). The major national quality metric repositories and clearinghouses were queried. Additional searches included the American Academy of Otolaryngology-Head and Neck Surgery database, PubMed, and Google to attempt to capture any additional quality metrics. Seven quality metrics for ARS and 4 quality metrics for CRS were identified. ARS metrics focused on appropriateness of diagnosis (n = 1), antibiotic prescribing (n = 4), and radiologic imaging (n = 2). CRS quality metrics focused on appropriateness of diagnosis (n = 1), radiologic imaging (n = 1), and measurement of patient quality of life (n = 2). The Physician Quality Reporting System (PQRS) currently tracks 3 ARS quality metrics and 1 CRS quality metric. There are no outcome-based rhinosinusitis quality metrics and no metrics that assess domains of safety, patient-centeredness, and timeliness of care. The current status of quality measurement for rhinosinusitis has focused primarily on the quality domain of efficiency and process measures for ARS. More work is needed to develop, validate, and track outcome-based quality metrics along with CRS-specific metrics. Although there has been excellent work done to improve quality measurement for rhinosinusitis, there remain major gaps and challenges that need to be considered during the development of future metrics. © 2017 ARS-AAOA, LLC.

Development of quality metrics for ambulatory pediatric cardiology: Infection prevention.

PubMed

Johnson, Jonathan N; Barrett, Cindy S; Franklin, Wayne H; Graham, Eric M; Halnon, Nancy J; Hattendorf, Brandy A; Krawczeski, Catherine D; McGovern, James J; O'Connor, Matthew J; Schultz, Amy H; Vinocur, Jeffrey M; Chowdhury, Devyani; Anderson, Jeffrey B

2017-12-01

In 2012, the American College of Cardiology's (ACC) Adult Congenital and Pediatric Cardiology Council established a program to develop quality metrics to guide ambulatory practices for pediatric cardiology. The council chose five areas on which to focus their efforts; chest pain, Kawasaki Disease, tetralogy of Fallot, transposition of the great arteries after arterial switch, and infection prevention. Here, we sought to describe the process, evaluation, and results of the Infection Prevention Committee's metric design process. The infection prevention metrics team consisted of 12 members from 11 institutions in North America. The group agreed to work on specific infection prevention topics including antibiotic prophylaxis for endocarditis, rheumatic fever, and asplenia/hyposplenism; influenza vaccination and respiratory syncytial virus prophylaxis (palivizumab); preoperative methods to reduce intraoperative infections; vaccinations after cardiopulmonary bypass; hand hygiene; and testing to identify splenic function in patients with heterotaxy. An extensive literature review was performed. When available, previously published guidelines were used fully in determining metrics. The committee chose eight metrics to submit to the ACC Quality Metric Expert Panel for review. Ultimately, metrics regarding hand hygiene and influenza vaccination recommendation for patients did not pass the RAND analysis. Both endocarditis prophylaxis metrics and the RSV/palivizumab metric passed the RAND analysis but fell out during the open comment period. Three metrics passed all analyses, including those for antibiotic prophylaxis in patients with heterotaxy/asplenia, for influenza vaccination compliance in healthcare personnel, and for adherence to recommended regimens of secondary prevention of rheumatic fever. The lack of convincing data to guide quality improvement initiatives in pediatric cardiology is widespread, particularly in infection prevention. Despite this, three metrics were able to be developed for use in the ACC's quality efforts for ambulatory practice. © 2017 Wiley Periodicals, Inc.

Application of online measures to monitor and evaluate multiplatform fusion performance

NASA Astrophysics Data System (ADS)

Stubberud, Stephen C.; Kowalski, Charlene; Klamer, Dale M.

1999-07-01

A primary concern of multiplatform data fusion is assessing the quality and utility of data shared among platforms. Constraints such as platform and sensor capability and task load necessitate development of an on-line system that computes a metric to determine which other platform can provide the best data for processing. To determine data quality, we are implementing an approach based on entropy coupled with intelligent agents. To determine data quality, we are implementing an approach based on entropy coupled with intelligent agents. Entropy measures quality of processed information such as localization, classification, and ambiguity in measurement-to-track association. Lower entropy scores imply less uncertainty about a particular target. When new information is provided, we compuete the level of improvement a particular track obtains from one measurement to another. The measure permits us to evaluate the utility of the new information. We couple entropy with intelligent agents that provide two main data gathering functions: estimation of another platform's performance and evaluation of the new measurement data's quality. Both functions result from the entropy metric. The intelligent agent on a platform makes an estimate of another platform's measurement and provides it to its own fusion system, which can then incorporate it, for a particular target. A resulting entropy measure is then calculated and returned to its own agent. From this metric, the agent determines a perceived value of the offboard platform's measurement. If the value is satisfactory, the agent requests the measurement from the other platform, usually by interacting with the other platform's agent. Once the actual measurement is received, again entropy is computed and the agent assesses its estimation process and refines it accordingly.

Viewers' perceptions of a YouTube music therapy session video.

PubMed

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.

A Single Conjunction Risk Assessment Metric: the F-Value

NASA Technical Reports Server (NTRS)

Frigm, Ryan Clayton; Newman, Lauri K.

2009-01-01

The Conjunction Assessment Team at NASA Goddard Space Flight Center provides conjunction risk assessment for many NASA robotic missions. These risk assessments are based on several figures of merit, such as miss distance, probability of collision, and orbit determination solution quality. However, these individual metrics do not singly capture the overall risk associated with a conjunction, making it difficult for someone without this complete understanding to take action, such as an avoidance maneuver. The goal of this analysis is to introduce a single risk index metric that can easily convey the level of risk without all of the technical details. The proposed index is called the conjunction "F-value." This paper presents the concept of the F-value and the tuning of the metric for use in routine Conjunction Assessment operations.

Simultaneous compression and encryption for secure real-time secure transmission of sensitive video transmission

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.

Quality of pharmaceutical care at the pharmacy counter: patients’ experiences versus video observation

PubMed Central

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

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.

Overlay accuracy fundamentals

NASA Astrophysics Data System (ADS)

Kandel, Daniel; Levinski, Vladimir; Sapiens, Noam; Cohen, Guy; Amit, Eran; Klein, Dana; Vakshtein, Irina

2012-03-01

Currently, the performance of overlay metrology is evaluated mainly based on random error contributions such as precision and TIS variability. With the expected shrinkage of the overlay metrology budget to < 0.5nm, it becomes crucial to include also systematic error contributions which affect the accuracy of the metrology. Here we discuss fundamental aspects of overlay accuracy and a methodology to improve accuracy significantly. We identify overlay mark imperfections and their interaction with the metrology technology, as the main source of overlay inaccuracy. The most important type of mark imperfection is mark asymmetry. Overlay mark asymmetry leads to a geometrical ambiguity in the definition of overlay, which can be ~1nm or less. It is shown theoretically and in simulations that the metrology may enhance the effect of overlay mark asymmetry significantly and lead to metrology inaccuracy ~10nm, much larger than the geometrical ambiguity. The analysis is carried out for two different overlay metrology technologies: Imaging overlay and DBO (1st order diffraction based overlay). It is demonstrated that the sensitivity of DBO to overlay mark asymmetry is larger than the sensitivity of imaging overlay. Finally, we show that a recently developed measurement quality metric serves as a valuable tool for improving overlay metrology accuracy. Simulation results demonstrate that the accuracy of imaging overlay can be improved significantly by recipe setup optimized using the quality metric. We conclude that imaging overlay metrology, complemented by appropriate use of measurement quality metric, results in optimal overlay accuracy.

Testing of the Apollo 15 Metric Camera System.

NASA Technical Reports Server (NTRS)

Helmering, R. J.; Alspaugh, D. H.

1972-01-01

Description of tests conducted (1) to assess the quality of Apollo 15 Metric Camera System data and (2) to develop production procedures for total block reduction. Three strips of metric photography over the Hadley Rille area were selected for the tests. These photographs were utilized in a series of evaluation tests culminating in an orbitally constrained block triangulation solution. Results show that film deformations up to 25 and 5 microns are present in the mapping and stellar materials, respectively. Stellar reductions can provide mapping camera orientations with an accuracy that is consistent with the accuracies of other parameters in the triangulation solutions. Pointing accuracies of 4 to 10 microns can be expected for the mapping camera materials, depending on variations in resolution caused by changing sun angle conditions.

Feasibility study of transmission of OTV camera control information in the video vertical blanking interval

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.

Implementation and Analysis of Real-Time Streaming Protocols

PubMed Central

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

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.

Does training with 3D videos improve decision-making in team invasion sports?

PubMed

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.

Benefit from NASA

NASA Image and Video Library

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.

Implementation and Analysis of Real-Time Streaming Protocols.

PubMed

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.

Using Supplementary Video in Multimedia Instruction as a Teaching Tool to Increase Efficiency of Learning and Quality of Experience

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…

Use of Video Modeling and Video Prompting Interventions for Teaching Daily Living Skills to Individuals with Autism Spectrum Disorders: A Review

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…

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.

YouTube as an information source for pediatric adenotonsillectomy and ear tube surgery.

PubMed

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.

Naval Research Laboratory 1984 Review.

DTIC Science & Technology

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

North Dakota Interactive Video Network: A Practical Guide to Teleconferencing and Distance Education.

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…

A Comparison of Video- and Audio-Mediated Listening Tests with Many-Facet Rasch Modeling and Differential Distractor Functioning

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…

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.

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.

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.

Correlating optical bench performance with clinical defocus curves in varifocal and trifocal intraocular lenses.

PubMed

Plaza-Puche, Ana B; Alió, Jorge L; MacRae, Scott; Zheleznyak, Len; Sala, Esperanza; Yoon, Geunyoung

2015-05-01

To investigate the correlations existing between a trifocal intraocular lens (IOL) and a varifocal IOL using the "ex vivo" optical bench through-focus image quality analysis and the clinical visual performance in real patients by study of the defocus curves. This prospective, consecutive, nonrandomized, comparative study included a total of 64 eyes of 42 patients. Three groups of eyes were differentiated according to the IOL implanted: 22 eyes implanted with the varifocal Lentis Mplus LS-313 IOL (Oculentis GmbH, Berlin, Germany); 22 eyes implanted with the trifocal FineVision IOL (Physiol, Liege, Belgium), and 20 eyes implanted with the monofocal Acrysof SA60AT IOL (Alcon Laboratories, Inc., Fort Worth, TX). Visual outcomes and defocus curve were evaluated postoperatively. Optical bench through-focus performance was quantified by computing an image quality metric and the cross-correlation coefficient between an unaberrated reference image and captured retinal images from a model eye with a 3.0-mm artificial pupil. Statistically significant differences among defocus curves of different IOLs were detected for the levels of defocus from -4.00 to -1.00 diopters (D) (P < .01). Significant correlations were found between the optical bench image quality metric results and logMAR visual acuity scale in all groups (Lentis Mplus group: r = -0.97, P < .01; FineVision group: r = -0.82, P < .01; Acrys of group: r = -0.99, P < .01). Linear predicting models were obtained. Significant correlations were found between logMAR visual acuity and image quality metric for the multifocal and monofocal IOLs analyzed. This finding enables surgeons to predict visual outcomes from the optical bench analysis. Copyright 2015, SLACK Incorporated.

Assessing oral health-related quality of life in children and adolescents: a systematic review and standardized comparison of available instruments.

PubMed

Zaror, Carlos; Pardo, Yolanda; Espinoza-Espinoza, Gerardo; Pont, Àngels; Muñoz-Millán, Patricia; Martínez-Zapata, María José; Vilagut, Gemma; Forero, Carlos G; Garin, Olatz; Alonso, Jordi; Ferrer, Montse

2018-03-22

To obtain a systematic and standardized evaluation of the current evidence on development process, metric properties, and administration issues of oral health-related quality of life instruments available for children and adolescents. A systematic search until October 2016 was conducted in PubMed, Embase, Lilacs, SciELO, and Cochrane databases. Articles with information regarding the development process, metric properties, and administration issues of pediatric instruments measuring oral health-related quality of life were eligible for inclusion. Two researchers independently evaluated each instrument applying the Evaluating Measures of Patient-Reported Outcomes (EMPRO) tool. An overall and seven attribute-specific EMPRO scores were calculated (range 0-100, worst to best): measurement model, reliability, validity, responsiveness, interpretability, burden, and alternative forms. We identified 18 instruments evaluated in 132 articles. From five instruments designed for preschoolers, the Early Childhood Oral Health Impact Scale (ECOHIS) obtained the highest overall EMPRO score (82.2). Of nine identified for schoolchildren and adolescents, the best rated instrument was the Child Perceptions Questionnaire 11-14 (82.1). Among the four instruments developed for any age, the Family Impact Scale (FIS) obtained the highest scores (80.3). The evidence supports the use of the ECOHIS for preschoolers, while the age is a key factor when choosing among the four recommended instruments for schoolchildren and adolescents. Instruments for specific conditions, symptoms, or treatments need further research on metric properties. Our results facilitate decision-making on the correct oral health-related quality of life instrument selection for any certain study purpose and population during the childhood and adolescence life cycle.

Tools for observational gait analysis in patients with stroke: a systematic review.

PubMed

Ferrarello, Francesco; Bianchi, Valeria Anna Maria; Baccini, Marco; Rubbieri, Gaia; Mossello, Enrico; Cavallini, Maria Chiara; Marchionni, Niccolò; Di Bari, Mauro

2013-12-01

Stroke severely affects walking ability, and assessment of gait kinematics is important in defining diagnosis, planning treatment, and evaluating interventions in stroke rehabilitation. Although observational gait analysis is the most common approach to evaluate gait kinematics, tools useful for this purpose have received little attention in the scientific literature and have not been thoroughly reviewed. The aims of this systematic review were to identify tools proposed to conduct observational gait analysis in adults with a stroke, to summarize evidence concerning their quality, and to assess their implementation in rehabilitation research and clinical practice. An extensive search was performed of original articles reporting on visual/observational tools developed to investigate gait kinematics in adults with a stroke. Two reviewers independently selected studies, extracted data, assessed quality of the included studies, and scored the metric properties and clinical utility of each tool. Rigor in reporting metric properties and dissemination of the tools also was evaluated. Five tools were identified, not all of which had been tested adequately for their metric properties. Evaluation of content validity was partially satisfactory. Reliability was poorly investigated in all but one tool. Concurrent validity and sensitivity to change were shown for 3 and 2 tools, respectively. Overall, adequate levels of quality were rarely reached. The dissemination of the tools was poor. Based on critical appraisal, the Gait Assessment and Intervention Tool shows a good level of quality, and its use in stroke rehabilitation is recommended. Rigorous studies are needed for the other tools in order to establish their usefulness.

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.

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.

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).

Open-Source Telemedicine Platform for Wireless Medical Video Communication

PubMed Central

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

Measuring economic complexity of countries and products: which metric to use?

NASA Astrophysics Data System (ADS)

Mariani, Manuel Sebastian; Vidmer, Alexandre; Medo, Matsúš; Zhang, Yi-Cheng

2015-11-01

Evaluating the economies of countries and their relations with products in the global market is a central problem in economics, with far-reaching implications to our theoretical understanding of the international trade as well as to practical applications, such as policy making and financial investment planning. The recent Economic Complexity approach aims to quantify the competitiveness of countries and the quality of the exported products based on the empirical observation that the most competitive countries have diversified exports, whereas developing countries only export few low quality products - typically those exported by many other countries. Two different metrics, Fitness-Complexity and the Method of Reflections, have been proposed to measure country and product score in the Economic Complexity framework. We use international trade data and a recent ranking evaluation measure to quantitatively compare the ability of the two metrics to rank countries and products according to their importance in the network. The results show that the Fitness-Complexity metric outperforms the Method of Reflections in both the ranking of products and the ranking of countries. We also investigate a generalization of the Fitness-Complexity metric and show that it can produce improved rankings provided that the input data are reliable.

NMF-Based Image Quality Assessment Using Extreme Learning Machine.

PubMed

Wang, Shuigen; Deng, Chenwei; Lin, Weisi; Huang, Guang-Bin; Zhao, Baojun

2017-01-01

Numerous state-of-the-art perceptual image quality assessment (IQA) algorithms share a common two-stage process: distortion description followed by distortion effects pooling. As for the first stage, the distortion descriptors or measurements are expected to be effective representatives of human visual variations, while the second stage should well express the relationship among quality descriptors and the perceptual visual quality. However, most of the existing quality descriptors (e.g., luminance, contrast, and gradient) do not seem to be consistent with human perception, and the effects pooling is often done in ad-hoc ways. In this paper, we propose a novel full-reference IQA metric. It applies non-negative matrix factorization (NMF) to measure image degradations by making use of the parts-based representation of NMF. On the other hand, a new machine learning technique [extreme learning machine (ELM)] is employed to address the limitations of the existing pooling techniques. Compared with neural networks and support vector regression, ELM can achieve higher learning accuracy with faster learning speed. Extensive experimental results demonstrate that the proposed metric has better performance and lower computational complexity in comparison with the relevant state-of-the-art approaches.

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.

High efficiency video coding for ultrasound video communication in m-health systems.

PubMed

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.

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.

76 FR 45397 - Export Inspection and Weighing Waiver for High Quality Specialty Grain Transported in Containers

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-29

... compared to an average $0.34 per metric ton for traditional grain exports. On December 13, 2005, GIPSA... mandatory inspection and weighing requirements of the USGSA that would adversely affect the marketing system... established the waiver to facilitate the marketing of high quality specialty grain by eliminating the burden...

Floristic Quality Index for woodland ground flora restoration: Utility and effectiveness in a fire-managed landscape

Treesearch

Calvin J. Maginel; Benjamin O. Knapp; John M. Kabrick; Rose-Marie Muzika

2016-01-01

Monitoring is a critical component of ecological restoration and requires the use of metrics that are meaningful and interpretable. We analyzed the effectiveness of the Floristic Quality Index (FQI), a vegetative community metric based on species richness and the level of sensitivity to anthropogenic disturbance of individual species present (Coefficient of...

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.

Multimedia in 1992.

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)

Correlation between the signal-to-noise ratio improvement factor (KSNR) and clinical image quality for chest imaging with a computed radiography system

NASA Astrophysics Data System (ADS)

Moore, C. S.; Wood, T. J.; Saunderson, J. R.; Beavis, A. W.

2015-12-01

This work assessed the appropriateness of the signal-to-noise ratio improvement factor (KSNR) as a metric for the optimisation of computed radiography (CR) of the chest. The results of a previous study in which four experienced image evaluators graded computer simulated chest images using a visual grading analysis scoring (VGAS) scheme to quantify the benefit of using an anti-scatter grid were used for the clinical image quality measurement (number of simulated patients  =  80). The KSNR was used to calculate the improvement in physical image quality measured in a physical chest phantom. KSNR correlation with VGAS was assessed as a function of chest region (lung, spine and diaphragm/retrodiaphragm), and as a function of x-ray tube voltage in a given chest region. The correlation of the latter was determined by the Pearson correlation coefficient. VGAS and KSNR image quality metrics demonstrated no correlation in the lung region but did show correlation in the spine and diaphragm/retrodiaphragmatic regions. However, there was no correlation as a function of tube voltage in any region; a Pearson correlation coefficient (R) of  -0.93 (p  =  0.015) was found for lung, a coefficient (R) of  -0.95 (p  =  0.46) was found for spine, and a coefficient (R) of  -0.85 (p  =  0.015) was found for diaphragm. All demonstrate strong negative correlations indicating conflicting results, i.e. KSNR increases with tube voltage but VGAS decreases. Medical physicists should use the KSNR metric with caution when assessing any potential improvement in clinical chest image quality when introducing an anti-scatter grid for CR imaging, especially in the lung region. This metric may also be a limited descriptor of clinical chest image quality as a function of tube voltage when a grid is used routinely.

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.

Interpolation of Water Quality Along Stream Networks from Synoptic Data

NASA Astrophysics Data System (ADS)

Lyon, S. W.; Seibert, J.; Lembo, A. J.; Walter, M. T.; Gburek, W. J.; Thongs, D.; Schneiderman, E.; Steenhuis, T. S.

2005-12-01

Effective catchment management requires water quality monitoring that identifies major pollutant sources and transport and transformation processes. While traditional monitoring schemes involve regular sampling at fixed locations in the stream, there is an interest synoptic or `snapshot' sampling to quantify water quality throughout a catchment. This type of sampling enables insights to biogeochemical behavior throughout a stream network at low flow conditions. Since baseflow concentrations are temporally persistence, they are indicative of the health of the ecosystems. A major problem with snapshot sampling is the lack of analytical techniques to represent the spatially distributed data in a manner that is 1) easily understood, 2) representative of the stream network, and 3) capable of being used to develop land management scenarios. This study presents a kriging application using the landscape composition of the contributing area along a stream network to define a new distance metric. This allows for locations that are more `similar' to stay spatially close together while less similar locations `move' further apart. We analyze a snapshot sampling campaign consisting of 125 manually collected grab samples during a summer recession flow period in the Townbrook Research Watershed. The watershed is located in the Catskill region of New York State and represents the mixed forest-agriculture land uses of the region. Our initial analysis indicated that stream nutrients (nitrogen and phosphorus) and chemical (major cations and anions) concentrations are controlled by the composition of landscape characteristics (landuse classes and soil types) surrounding the stream. Based on these relationships, an intuitively defined distance metric is developed by combining the traditional distance between observations and the relative difference in composition of contributing area. This metric is used to interpolate between the sampling locations with traditional geostatistic techniques (semivariograms and ordinary kriging). The resulting interpolations provide continuous stream nutrient and chemical concentrations with reduced kriging RMSE (i.e., the interpolation fits the actual data better) performed without path restriction to the stream channel (i.e., the current default for most geostatistical packages) or performed with an in-channel, Euclidean distance metric (i.e., `as the fish swims' distance). In addition to being quantifiably better, the new metric also produces maps of stream concentrations that match expected continuous stream concentrations based on expert knowledge of the watershed. This analysis and its resulting stream concentration maps provide a representation of spatially distributed synoptic data that can be used to quantify water quality for more effective catchment management that focuses on pollutant sources and transport and transformation processes.

Defining quality for distal pancreatectomy: does the laparoscopic approach protect patients from poor quality outcomes?

PubMed

Baker, Marshall S; Sherman, Karen L; Stocker, Susan; Hayman, Amanda V; Bentrem, David J; Prinz, Richard A; Talamonti, Mark S

2013-02-01

Established systems for grading postoperative complications do not change the assigned grade when multiple interventions or readmissions are required to manage a complication. Studies using these systems may misrepresent outcomes for the surgical procedures being evaluated. We define a quality outcome for distal pancreatectomy (DP) and use this metric to compare laparoscopic distal pancreatectomy (LDP) to open distal pancreatectomy (ODP). Records for patients undergoing DP between January 2006 and December 2009 were reviewed. Clavien-Dindo grade IIIb, IV, and V complications were classified as severe adverse--poor quality--postoperative outcomes (SAPOs). II and IIIa complications requiring either significantly prolonged overall lengths of stay including readmissions within 90 days or more than one invasive intervention were also classified as SAPOs. By Clavien-Dindo system alone, 91 % of DP patients had either no complication or a low/moderate grade (I, II, IIIa) complication. Using our reclassification, however, 25 % had a SAPO. Patients undergoing LDP demonstrated a Clavien-Dindo complication profile identical to that for SDP but demonstrated significantly shorter overall lengths of stay, were less likely to require perioperative transfusion, and less likely to have a SAPO. Established systems undergrade the severity of some complications following DP. Using a procedure-specific metric for quality, we demonstrate that LDP affords a higher quality postoperative outcome than ODP.

Meteorologically estimated exposure but not distance predicts asthma symptoms in schoolchildren in the environs of a petrochemical refinery: a cross-sectional study

PubMed Central

2009-01-01

Background Community concern about asthma prompted an epidemiological study of children living near a petrochemical refinery in Cape Town, South Africa. Because of resource constraints and the complexity of refinery emissions, neither direct environmental measurements nor modelling of airborne pollutants was possible. Instead a meteorologically derived exposure metric was calculated with the refinery as the putative point source. The study aimed to determine whether (1) asthma symptom prevalences were elevated compared to comparable areas in Cape Town and (2) whether there was an association between asthma symptom prevalences and the derived exposure metric. Methods A cross-sectional study was carried out of all consenting school children aged 11 to 14 years attending schools in a defined area, utilizing the International Study of Asthma and Allergy in Childhood (ISAAC) written and video questionnaires. Information was collected on potential confounders, e.g. parental history of atopic disease, active and passive smoking by the participant, birth order, number of children in the home and distance from a major road. The exposure metric combined residential distance of each child from the refinery with a wind vector in the form of wind speed, wind direction and proportion of the year blown. Results A total of 2,361 children from 17 schools met the criteria for inclusion. In multivariate analysis, meteorologically estimated exposure (MEE), but not simple distance from the refinery, was positively associated with having to take an inhaler to school [odds ratio per interquartile range (OR) 1.22, 95% confidence interval (CI) 1.06-1.40], and with a number of video elicited asthma symptoms, including recent waking with wheezing (OR 1.33, 95% CI 1.06-1.66) and frequent wheezing at rest (OR 1.27, 95% CI 1.05 - 1.54). Symptom prevalences were higher than in other areas of the city, with frequent waking with wheezing being in great excess (OR 8.92, 95% CI 4.79-16.63). Conclusion The results support the hypothesis of an increased prevalence of asthma symptoms among children in the area as a result of refinery emissions and provide a substantive basis for community concern. The methodology also provides a low cost means of testing hypotheses about point source pollutant effects on surrounding populations of children. PMID:19781087

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.

Effective deep learning training for single-image super-resolution in endomicroscopy exploiting video-registration-based reconstruction.

PubMed

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.

Quality optimization of H.264/AVC video transmission over noisy environments using a sparse regression framework

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.

Requirement Metrics for Risk Identification

NASA Technical Reports Server (NTRS)

Hammer, Theodore; Huffman, Lenore; Wilson, William; Rosenberg, Linda; Hyatt, Lawrence

1996-01-01

The Software Assurance Technology Center (SATC) is part of the Office of Mission Assurance of the Goddard Space Flight Center (GSFC). The SATC's mission is to assist National Aeronautics and Space Administration (NASA) projects to improve the quality of software which they acquire or develop. The SATC's efforts are currently focused on the development and use of metric methodologies and tools that identify and assess risks associated with software performance and scheduled delivery. This starts at the requirements phase, where the SATC, in conjunction with software projects at GSFC and other NASA centers is working to identify tools and metric methodologies to assist project managers in identifying and mitigating risks. This paper discusses requirement metrics currently being used at NASA in a collaborative effort between the SATC and the Quality Assurance Office at GSFC to utilize the information available through the application of requirements management tools.

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.

A qualitative analysis of methotrexate self-injection education videos on YouTube.

PubMed

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.

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.

An Evaluation of a Diabetes Self-Management Education (DSME) Intervention Delivered Using Avatar-Based Technology: Certified Diabetes Educators' Ratings and Perceptions.

PubMed

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.

Educational Quality of YouTube Videos in Thumb Exercises for Carpometacarpal Osteoarthritis: A Search on Current Practice.

PubMed

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.

Video-based instructions for surgical hand disinfection as a replacement for conventional tuition? A randomised, blind comparative study.

PubMed

Weber, Uwe; Constantinescu, Mihai A; Woermann, Ulrich; Schmitz, Felix; Schnabel, Kai

2016-01-01

Various different learning methods are available for planning tuition regarding the introduction to surgical hand disinfection. These learning methods should help to organise and deal with this topic. The use of a video film is an alternative to conventional tuition due to the real presentation possibilities of practical demonstration. This study examines by way of comparison which form of communication is more effective for learning and applying surgical hand disinfection for medical students in their first year of studies: video-based instruction or conventional tuition. A total of 50 first-year medical students were randomly allocated either to the "Conventional Instruction" (CI) study group or to the "Video-based Instruction" (VI) study group. The conventional instruction was carried out by an experienced nurse preceptor/nurse educator for the operating theatre who taught the preparatory measures and the actual procedure in a two-minute lesson. The second group watched a two-minute video sequence with identical content. Afterwards, both groups demonstrated practically the knowledge they had acquired at an individual practical test station. The quality (a) of the preparation and (b) of the procedure as well as (c) the quality of the results was assessed by 6 blind experts using a check list. The acceptability of the respective teaching method was also asked about using a questionnaire. The group performance did not differ either in the preparation (t=-78, p<0.44) or in the quality (t=-99, p<0.34). With respect to performance, it was possible to demonstrate a strong treatment effect. In the practical (t=-3.33, p<0.002, d=0.943) and in the total score (t=-2.65, p<0.011, d=0.751), the group with video-based instruction achieved a significantly better result. In response to the question as to which of the two learning methods they would prefer, the significant majority (60.4%) of students stated video instruction. In this study, the use of the video-based instruction emerged as the more effective teaching method for learning surgical hand disinfection for medical students and is preferable to conventional instruction. The video instruction is associated with a higher learning effectiveness, efficiency and acceptability.

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.

Building a Patient-Reported Outcome Metric Database: One Hospital's Experience.

PubMed

Rana, Adam J

2016-06-01

A number of provisions exist within the Patient Protection and Affordable Care Act that focus on improving the delivery of health care in the United States, including quality of care. From a total joint arthroplasty perspective, the issue of quality increasingly refers to quantifying patient-reported outcome metrics (PROMs). This article describes one hospital's experience in building and maintaining an electronic PROM database for a practice of 6 board-certified orthopedic surgeons. The surgeons advocated to and worked with the hospital to contract with a joint registry database company and hire a research assistant. They implemented a standardized process for all surgical patients to fill out patient-reported outcome questionnaires at designated intervals. To date, the group has collected patient-reported outcome metric data for >4500 cases. The data are frequently used in different venues at the hospital including orthopedic quality metric and research meetings. In addition, the results were used to develop an annual outcome report. The annual report is given to patients and primary care providers, and portions of it are being used in discussions with insurance carriers. Building an electronic database to collect PROMs is a group undertaking and requires a physician champion. A considerable amount of work needs to be done up front to make its introduction a success. Once established, a PROM database can provide a significant amount of information and data that can be effectively used in multiple capacities. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessing precision, bias and sigma-metrics of 53 measurands of the Alinity ci system.

PubMed

Westgard, Sten; Petrides, Victoria; Schneider, Sharon; Berman, Marvin; Herzogenrath, Jörg; Orzechowski, Anthony

2017-12-01

Assay performance is dependent on the accuracy and precision of a given method. These attributes can be combined into an analytical Sigma-metric, providing a simple value for laboratorians to use in evaluating a test method's capability to meet its analytical quality requirements. Sigma-metrics were determined for 37 clinical chemistry assays, 13 immunoassays, and 3 ICT methods on the Alinity ci system. Analytical Performance Specifications were defined for the assays, following a rationale of using CLIA goals first, then Ricos Desirable goals when CLIA did not regulate the method, and then other sources if the Ricos Desirable goal was unrealistic. A precision study was conducted at Abbott on each assay using the Alinity ci system following the CLSI EP05-A2 protocol. Bias was estimated following the CLSI EP09-A3 protocol using samples with concentrations spanning the assay's measuring interval tested in duplicate on the Alinity ci system and ARCHITECT c8000 and i2000 SR systems, where testing was also performed at Abbott. Using the regression model, the %bias was estimated at an important medical decisions point. Then the Sigma-metric was estimated for each assay and was plotted on a method decision chart. The Sigma-metric was calculated using the equation: Sigma-metric=(%TEa-|%bias|)/%CV. The Sigma-metrics and Normalized Method Decision charts demonstrate that a majority of the Alinity assays perform at least at five Sigma or higher, at or near critical medical decision levels. More than 90% of the assays performed at Five and Six Sigma. None performed below Three Sigma. Sigma-metrics plotted on Normalized Method Decision charts provide useful evaluations of performance. The majority of Alinity ci system assays had sigma values >5 and thus laboratories can expect excellent or world class performance. Laboratorians can use these tools as aids in choosing high-quality products, further contributing to the delivery of excellent quality healthcare for patients. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

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.

Improving Quality Metric Adherence to Minimally Invasive Breast Biopsy among Surgeons Within a Multihospital Health Care System.

PubMed

Tjoe, Judy A; Greer, Danielle M; Ihde, Sue E; Bares, Diane A; Mikkelson, Wendy M; Weese, James L

2015-09-01

Minimally invasive breast biopsy (MIBB) is the procedure of choice for diagnosing breast lesions indeterminate for malignancy. Multihospital health care systems face challenges achieving systemwide adherence to standardized guidelines among surgeons with varying practice patterns. This study tested whether providing individual feedback about surgeons' use of MIBB to diagnose breast malignancies improved quality metric adherence across a large health care organization. We conducted a prospective matched-pairs study to test differences (or lack of agreement) between periods before and after intervention. All analytical cases of primary breast cancer diagnosed during 2011 (period 1) and from July 2012 to June 2013 (period 2) across a multihospital health care system were reviewed for initial diagnosis by MIBB or open surgical biopsy. Open surgical biopsy was considered appropriate care only if MIBB could not be performed for reasons listed in the American Society of Breast Surgeons' quality measure for preoperative diagnosis of breast cancer. Individual and systemwide results of adherence to the MIBB metric during period 1 were sent to each surgeon in June 2012 and were later compared with period 2 results using McNemar's test of marginal homogeneity for matched binary responses. Forty-six surgeons were evaluated on use of MIBB to diagnose breast cancer. In period 1, metric adherence for 100% of cases was achieved by 37 surgeons, for a systemwide 100% compliance rate of 80.4%. After notification of individual performance, 44 of 46 surgeons used MIBB solely or otherwise appropriate care to diagnose breast cancer, which improved systemwide compliance to 95.7%. Providing individual and systemwide performance results to surgeons can increase self-awareness of practice patterns when diagnosing breast cancer, leading to standardized best-practice care across a large health care organization. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Video Elicitation Interviews: A Qualitative Research Method for Investigating Physician-Patient Interactions

PubMed Central

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

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.

Video elicitation interviews: a qualitative research method for investigating physician-patient interactions.

PubMed

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.

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.

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...

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...

Benefits of utilizing CellProfiler as a characterization tool for U–10Mo nuclear fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collette, R.; Douglas, J.; Patterson, L.

2015-07-15

Automated image processing techniques have the potential to aid in the performance evaluation of nuclear fuels by eliminating judgment calls that may vary from person-to-person or sample-to-sample. Analysis of in-core fuel performance is required for design and safety evaluations related to almost every aspect of the nuclear fuel cycle. This study presents a methodology for assessing the quality of uranium–molybdenum fuel images and describes image analysis routines designed for the characterization of several important microstructural properties. The analyses are performed in CellProfiler, an open-source program designed to enable biologists without training in computer vision or programming to automatically extract cellularmore » measurements from large image sets. The quality metric scores an image based on three parameters: the illumination gradient across the image, the overall focus of the image, and the fraction of the image that contains scratches. The metric presents the user with the ability to ‘pass’ or ‘fail’ an image based on a reproducible quality score. Passable images may then be characterized through a separate CellProfiler pipeline, which enlists a variety of common image analysis techniques. The results demonstrate the ability to reliably pass or fail images based on the illumination, focus, and scratch fraction of the image, followed by automatic extraction of morphological data with respect to fission gas voids, interaction layers, and grain boundaries. - Graphical abstract: Display Omitted - Highlights: • A technique is developed to score U–10Mo FIB-SEM image quality using CellProfiler. • The pass/fail metric is based on image illumination, focus, and area scratched. • Automated image analysis is performed in pipeline fashion to characterize images. • Fission gas void, interaction layer, and grain boundary coverage data is extracted. • Preliminary characterization results demonstrate consistency of the algorithm.« less

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...

The quality of video information on burn first aid available on YouTube.

PubMed

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.

Clinical applications of commercially available video recording and monitoring systems: inexpensive, high-quality video recording and monitoring systems for endoscopy and microsurgery.

PubMed

Tsunoda, Koichi; Tsunoda, Atsunobu; Ishimoto, ShinnIchi; Kimura, Satoko

2006-01-01

The exclusive charge-coupled device (CCD) camera system for the endoscope and electronic fiberscopes are in widespread use. However, both are usually stationary in an office or examination room, and a wheeled cart is needed for mobility. The total costs of the CCD camera system and electronic fiberscopy system are at least US Dollars 10,000 and US Dollars 30,000, respectively. Recently, the performance of audio and visual instruments has improved dramatically, with a concomitant reduction in their cost. Commercially available CCD video cameras with small monitors have become common. They provide excellent image quality and are much smaller and less expensive than previous models. The authors have developed adaptors for the popular mini-digital video (mini-DV) camera. The camera also provides video and acoustic output signals; therefore, the endoscopic images can be viewed on a large monitor simultaneously. The new system (a mini-DV video camera and an adaptor) costs only US Dollars 1,000. Therefore, the system is both cost-effective and useful for the outpatient clinic or casualty setting, or on house calls for the purpose of patient education. In the future, the authors plan to introduce the clinical application of a high-vision camera and an infrared camera as medical instruments for clinical and research situations.

Secured web-based video repository for multicenter studies

PubMed Central

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

Measuring quality in anatomic pathology.

PubMed

Raab, Stephen S; Grzybicki, Dana Marie

2008-06-01

This article focuses mainly on diagnostic accuracy in measuring quality in anatomic pathology, noting that measuring any quality metric is complex and demanding. The authors discuss standardization and its variability within and across areas of care delivery and efforts involving defining and measuring error to achieve pathology quality and patient safety. They propose that data linking error to patient outcome are critical for developing quality improvement initiatives targeting errors that cause patient harm in addition to using methods of root cause analysis, beyond those traditionally used in cytologic-histologic correlation, to assist in the development of error reduction and quality improvement plans.

Satellite Power System (SPS) environmental impacts, preliminary assessment

NASA Technical Reports Server (NTRS)

Livingston, F. R.

1978-01-01

Present power plant assessment factors are used to present satellite power system (SPS) impacts. In contrast to oil, gas, nuclear and coal fueled power plants, the SPS and hydroelectric power plants produce air, water, and solid waste emissions only during the construction phase. Land use impacts result from the placement of rectennas used for microwave receiving and rectifying. Air quality impacts of the SPS resulting from the construction phase amount to 0.405 metric tons per megawatt year. Solid wastes impacts are 0.108 metric tons per year of operation. Other impacts such as those caused by heavy lift launch vehicle sites are also discussed.

Sleep state classification using pressure sensor mats.

PubMed

Baran Pouyan, M; Nourani, M; Pompeo, M

2015-08-01

Sleep state detection is valuable in assessing patient's sleep quality and in-bed general behavior. In this paper, a novel classification approach of sleep states (sleep, pre-wake, wake) is proposed that uses only surface pressure sensors. In our method, a mobility metric is defined based on successive pressure body maps. Then, suitable statistical features are computed based on the mobility metric. Finally, a customized random forest classifier is employed to identify various classes including a new class for pre-wake state. Our algorithm achieves 96.1% and 88% accuracies for two (sleep, wake) and three (sleep, pre-wake, wake) class identification, respectively.

Educational Video Recording and Editing for The Hand Surgeon

PubMed Central

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

Water surface modeling from a single viewpoint video.

PubMed

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.

Method for 3D noncontact measurements of cut trees package area

NASA Astrophysics Data System (ADS)

Knyaz, Vladimir A.; Vizilter, Yuri V.

2001-02-01

Progress in imaging sensors and computers create the background for numerous 3D imaging application for wide variety of manufacturing activity. Many demands for automated precise measurements are in wood branch of industry. One of them is the accurate volume definition for cut trees carried on the truck. The key point for volume estimation is determination of the front area of the cut tree package. To eliminate slow and inaccurate manual measurements being now in practice the experimental system for automated non-contact wood measurements is developed. The system includes two non-metric CCD video cameras, PC as central processing unit, frame grabbers and original software for image processing and 3D measurements. The proposed method of measurement is based on capturing the stereo pair of front of trees package and performing the image orthotranformation into the front plane. This technique allows to process transformed image for circle shapes recognition and calculating their area. The metric characteristics of the system are provided by special camera calibration procedure. The paper presents the developed method of 3D measurements, describes the hardware used for image acquisition and the software realized the developed algorithms, gives the productivity and precision characteristics of the system.

Comparing Phylogenetic Trees by Matching Nodes Using the Transfer Distance Between Partitions.

PubMed

Bogdanowicz, Damian; Giaro, Krzysztof

2017-05-01

Ability to quantify dissimilarity of different phylogenetic trees describing the relationship between the same group of taxa is required in various types of phylogenetic studies. For example, such metrics are used to assess the quality of phylogeny construction methods, to define optimization criteria in supertree building algorithms, or to find horizontal gene transfer (HGT) events. Among the set of metrics described so far in the literature, the most commonly used seems to be the Robinson-Foulds distance. In this article, we define a new metric for rooted trees-the Matching Pair (MP) distance. The MP metric uses the concept of the minimum-weight perfect matching in a complete bipartite graph constructed from partitions of all pairs of leaves of the compared phylogenetic trees. We analyze the properties of the MP metric and present computational experiments showing its potential applicability in tasks related to finding the HGT events.

Task-oriented lossy compression of magnetic resonance images

NASA Astrophysics Data System (ADS)

Anderson, Mark C.; Atkins, M. Stella; Vaisey, Jacques

1996-04-01

A new task-oriented image quality metric is used to quantify the effects of distortion introduced into magnetic resonance images by lossy compression. This metric measures the similarity between a radiologist's manual segmentation of pathological features in the original images and the automated segmentations performed on the original and compressed images. The images are compressed using a general wavelet-based lossy image compression technique, embedded zerotree coding, and segmented using a three-dimensional stochastic model-based tissue segmentation algorithm. The performance of the compression system is then enhanced by compressing different regions of the image volume at different bit rates, guided by prior knowledge about the location of important anatomical regions in the image. Application of the new system to magnetic resonance images is shown to produce compression results superior to the conventional methods, both subjectively and with respect to the segmentation similarity metric.

Comparing Phylogenetic Trees by Matching Nodes Using the Transfer Distance Between Partitions

PubMed Central

Giaro, Krzysztof

2017-01-01

Abstract Ability to quantify dissimilarity of different phylogenetic trees describing the relationship between the same group of taxa is required in various types of phylogenetic studies. For example, such metrics are used to assess the quality of phylogeny construction methods, to define optimization criteria in supertree building algorithms, or to find horizontal gene transfer (HGT) events. Among the set of metrics described so far in the literature, the most commonly used seems to be the Robinson–Foulds distance. In this article, we define a new metric for rooted trees—the Matching Pair (MP) distance. The MP metric uses the concept of the minimum-weight perfect matching in a complete bipartite graph constructed from partitions of all pairs of leaves of the compared phylogenetic trees. We analyze the properties of the MP metric and present computational experiments showing its potential applicability in tasks related to finding the HGT events. PMID:28177699

Quantitative evaluation of low-cost frame-grabber boards for personal computers.

PubMed

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.

Comparative study of probability distribution distances to define a metric for the stability of multi-source biomedical research data.

PubMed

Sáez, Carlos; Robles, Montserrat; García-Gómez, Juan Miguel

2013-01-01

Research biobanks are often composed by data from multiple sources. In some cases, these different subsets of data may present dissimilarities among their probability density functions (PDF) due to spatial shifts. This, may lead to wrong hypothesis when treating the data as a whole. Also, the overall quality of the data is diminished. With the purpose of developing a generic and comparable metric to assess the stability of multi-source datasets, we have studied the applicability and behaviour of several PDF distances over shifts on different conditions (such as uni- and multivariate, different types of variable, and multi-modality) which may appear in real biomedical data. From the studied distances, we found information-theoretic based and Earth Mover's Distance to be the most practical distances for most conditions. We discuss the properties and usefulness of each distance according to the possible requirements of a general stability metric.

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.

Annual Technical Symposium (28th): Achieving Technical and Management Excellence. Held in Arlington, Virginia on April 11, 1991,

DTIC Science & Technology

1991-04-11

Perplexed: Think Energy Again. Video Enhanced SECAT - An Energy Program; Quality Ship Service Power with an Integrated Diesel Electric Propulsion...DIesign Branch (5011), NAVSEA * "Think Energy Again! Video Enhanced SECAT - 5 An Energy Program"’ Hasan Pehlivan, Mechanical Engineer/Ship Trials, Surface...1.015, or 1.5% increase.) Association of Scientists and Engineers 28th Annual Technical Symposium, 11 April 1991 THINK ENERGY AGAIN! A VIDEO ENHANCED

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…

A Simple Composite Metric for the Assessment of Glycemic Status from Continuous Glucose Monitoring Data: Implications for Clinical Practice and the Artificial Pancreas.

PubMed

Hirsch, Irl B; Balo, Andrew K; Sayer, Kevin; Garcia, Arturo; Buckingham, Bruce A; Peyser, Thomas A

2017-06-01

The potential clinical benefits of continuous glucose monitoring (CGM) have been recognized for many years, but CGM is used by a small fraction of patients with diabetes. One obstacle to greater use of the technology is the lack of simplified tools for assessing glycemic control from CGM data without complicated visual displays of data. We developed a simple new metric, the personal glycemic state (PGS), to assess glycemic control solely from continuous glucose monitoring data. PGS is a composite index that assesses four domains of glycemic control: mean glucose, glycemic variability, time in range and frequency and severity of hypoglycemia. The metric was applied to data from six clinical studies for the G4 Platinum continuous glucose monitoring system (Dexcom, San Diego, CA). The PGS was also applied to data from a study of artificial pancreas comparing results from open loop and closed loop in adolescents and in adults. The new metric for glycemic control, PGS, was able to characterize the quality of glycemic control in a wide range of study subjects with various mean glucose, minimal, moderate, and excessive glycemic variability and subjects on open loop versus closed loop control. A new composite metric for the assessment of glycemic control based on CGM data has been defined for use in assessing glycemic control in clinical practice and research settings. The new metric may help rapidly identify problems in glycemic control and may assist with optimizing diabetes therapy during time-constrained physician office visits.

Empirical Assessment of the Impact of Low-Cost Generic Programs on Adherence-Based Quality Measures

PubMed Central

Pauly, Nathan J.; Talbert, Jeffery C.; Brown, Joshua D.

2017-01-01

In the United States, federally-funded health plans are mandated to measure the quality of care. Adherence-based medication quality metrics depend on completeness of administrative claims data for accurate measurement. Low-cost generic programs (LCGPs) cause medications fills to be missing from claims data as medications are not adjudicated through a patient’s insurance. This study sought to assess the magnitude of the impact of LCGPs on these quality measures. Data from the 2012–2013 Medical Expenditure Panel Survey (MEPS) were used. Medication fills for select medication classes were classified as LCGP fills and individuals were classified as never, sometimes, and always users of LCGPs. Individuals were classified based on insurance type (private, Medicare, Medicaid, dual-eligible). The proportion of days covered (PDC) was calculated for each medication class and the proportion of users with PDC ≥ 0.80 was reported as an observed metric for what would be calculated based on claims data and a true metric which included missing medication fills due to LCGPs. True measures of adherence were higher than the observed measures. The effect’s magnitude was highest for private insurance and for medication classes utilized more often through LCGPs. Thus, medication-based quality measures may be underestimated due to LCGPs. PMID:28970427

Perceptual full-reference quality assessment of stereoscopic images by considering binocular visual characteristics.

PubMed

Shao, Feng; Lin, Weisi; Gu, Shanbo; Jiang, Gangyi; Srikanthan, Thambipillai

2013-05-01

Perceptual quality assessment is a challenging issue in 3D signal processing research. It is important to study 3D signal directly instead of studying simple extension of the 2D metrics directly to the 3D case as in some previous studies. In this paper, we propose a new perceptual full-reference quality assessment metric of stereoscopic images by considering the binocular visual characteristics. The major technical contribution of this paper is that the binocular perception and combination properties are considered in quality assessment. To be more specific, we first perform left-right consistency checks and compare matching error between the corresponding pixels in binocular disparity calculation, and classify the stereoscopic images into non-corresponding, binocular fusion, and binocular suppression regions. Also, local phase and local amplitude maps are extracted from the original and distorted stereoscopic images as features in quality assessment. Then, each region is evaluated independently by considering its binocular perception property, and all evaluation results are integrated into an overall score. Besides, a binocular just noticeable difference model is used to reflect the visual sensitivity for the binocular fusion and suppression regions. Experimental results show that compared with the relevant existing metrics, the proposed metric can achieve higher consistency with subjective assessment of stereoscopic images.

Application of a simple, affordable quality metric tool to colorectal, upper gastrointestinal, hernia, and hepatobiliary surgery patients: the HARM score.

PubMed

Brady, Justin T; Ko, Bona; Hohmann, Samuel F; Crawshaw, Benjamin P; Leinicke, Jennifer A; Steele, Scott R; Augestad, Knut M; Delaney, Conor P

2018-06-01

Quality is the major driver for both clinical and financial assessment. There remains a need for simple, affordable, quality metric tools to evaluate patient outcomes, which led us to develop the HospitAl length of stay, Readmission and Mortality (HARM) score. We hypothesized that the HARM score would be a reliable tool to assess patient outcomes across various surgical specialties. From 2011 to 2015, we identified colorectal, hepatobiliary, upper gastrointestinal, and hernia surgery admissions using the Vizient Clinical Database. Individual and hospital HARM scores were calculated from length of stay, 30-day readmission, and mortality rates. We evaluated the correlation of HARM scores with complication rates using the Clavien-Dindo classification. We identified 525,083 surgical patients: 206,981 colorectal, 164,691 hepatobiliary, 97,157 hernia, and 56,254 upper gastrointestinal. Overall, 53.8% of patients were admitted electively with a mean HARM score of 2.24; 46.2% were admitted emergently with a mean HARM score of 1.45 (p < 0.0001). All HARM components correlated with patient complications on logistic regression (p < 0.0001). The mean length of stay increased from 3.2 ± 1.8 days for a HARM score < 2 to 15.1 ± 12.2 days for a HARM score > 4 (p < 0.001). In elective admissions, for HARM categories of < 2, 2-< 3, 3-4, and > 4, complication rates were 9.3, 23.2, 38.8, and 71.6%, respectively. There was a similar trend for increasing HARM score in emergent admissions as well. For all surgical procedure categories, increasing HARM score, with and without risk adjustment, correlated with increasing severity of complications by Clavien-Dindo classification. The HARM score is an easy-to-use quality metric that correlates with increasing complication rates and complication severity across multiple surgical disciplines when evaluated on a large administrative database. This inexpensive tool could be adopted across multiple institutions to compare the quality of surgical care.

YouTube as a source of clinical skills education.

PubMed

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.

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.

The Completeness of the Fossil Record of Mesozoic Birds: Implications for Early Avian Evolution

PubMed Central

Brocklehurst, Neil; Upchurch, Paul; Mannion, Philip D.; O'Connor, Jingmai

2012-01-01

Many palaeobiological analyses have concluded that modern birds (Neornithes) radiated no earlier than the Maastrichtian, whereas molecular clock studies have argued for a much earlier origination. Here, we assess the quality of the fossil record of Mesozoic avian species, using a recently proposed character completeness metric which calculates the percentage of phylogenetic characters that can be scored for each taxon. Estimates of fossil record quality are plotted against geological time and compared to estimates of species level diversity, sea level, and depositional environment. Geographical controls on the avian fossil record are investigated by comparing the completeness scores of species in different continental regions and latitudinal bins. Avian fossil record quality varies greatly with peaks during the Tithonian-early Berriasian, Aptian, and Coniacian–Santonian, and troughs during the Albian-Turonian and the Maastrichtian. The completeness metric correlates more strongly with a ‘sampling corrected’ residual diversity curve of avian species than with the raw taxic diversity curve, suggesting that the abundance and diversity of birds might influence the probability of high quality specimens being preserved. There is no correlation between avian completeness and sea level, the number of fluviolacustrine localities or a recently constructed character completeness metric of sauropodomorph dinosaurs. Comparisons between the completeness of Mesozoic birds and sauropodomorphs suggest that small delicate vertebrate skeletons are more easily destroyed by taphonomic processes, but more easily preserved whole. Lagerstätten deposits might therefore have a stronger impact on reconstructions of diversity of smaller organisms relative to more robust forms. The relatively poor quality of the avian fossil record in the Late Cretaceous combined with very patchy regional sampling means that it is possible neornithine lineages were present throughout this interval but have not yet been sampled or are difficult to identify because of the fragmentary nature of the specimens. PMID:22761723

Emergency Video Telemedicine Consultation for Newborn Resuscitations: The Mayo Clinic Experience.

PubMed

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.

Wireless live streaming video of laparoscopic surgery: a bandwidth analysis for handheld computers.

PubMed

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.

Feasibility of dynamic cardiac ultrasound transmission via mobile phone for basic emergency teleconsultation.

PubMed

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.

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.

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.

Benefit from NASA

NASA Image and Video Library

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.

Deriving video content type from HEVC bitstream semantics

NASA Astrophysics Data System (ADS)

Nightingale, James; Wang, Qi; Grecos, Christos; Goma, Sergio R.

2014-05-01

As network service providers seek to improve customer satisfaction and retention levels, they are increasingly moving from traditional quality of service (QoS) driven delivery models to customer-centred quality of experience (QoE) delivery models. QoS models only consider metrics derived from the network however, QoE models also consider metrics derived from within the video sequence itself. Various spatial and temporal characteristics of a video sequence have been proposed, both individually and in combination, to derive methods of classifying video content either on a continuous scale or as a set of discrete classes. QoE models can be divided into three broad categories, full reference, reduced reference and no-reference models. Due to the need to have the original video available at the client for comparison, full reference metrics are of limited practical value in adaptive real-time video applications. Reduced reference metrics often require metadata to be transmitted with the bitstream, while no-reference metrics typically operate in the decompressed domain at the client side and require significant processing to extract spatial and temporal features. This paper proposes a heuristic, no-reference approach to video content classification which is specific to HEVC encoded bitstreams. The HEVC encoder already makes use of spatial characteristics to determine partitioning of coding units and temporal characteristics to determine the splitting of prediction units. We derive a function which approximates the spatio-temporal characteristics of the video sequence by using the weighted averages of the depth at which the coding unit quadtree is split and the prediction mode decision made by the encoder to estimate spatial and temporal characteristics respectively. Since the video content type of a sequence is determined by using high level information parsed from the video stream, spatio-temporal characteristics are identified without the need for full decoding and can be used in a timely manner to aid decision making in QoE oriented adaptive real time streaming.

Feathering effect detection and artifact agglomeration index-based video deinterlacing technique

NASA Astrophysics Data System (ADS)

Martins, André Luis; Rodrigues, Evandro Luis Linhari; de Paiva, Maria Stela Veludo

2018-03-01

Several video deinterlacing techniques have been developed, and each one presents a better performance in certain conditions. Occasionally, even the most modern deinterlacing techniques create frames with worse quality than primitive deinterlacing processes. This paper validates that the final image quality can be improved by combining different types of deinterlacing techniques. The proposed strategy is able to select between two types of deinterlaced frames and, if necessary, make the local correction of the defects. This decision is based on an artifact agglomeration index obtained from a feathering effect detection map. Starting from a deinterlaced frame produced by the "interfield average" method, the defective areas are identified, and, if deemed appropriate, these areas are replaced by pixels generated through the "edge-based line average" method. Test results have proven that the proposed technique is able to produce video frames with higher quality than applying a single deinterlacing technique through getting what is good from intra- and interfield methods.

Potential Adverse Effects of Violent Video Gaming: Interpersonal- Affective Traits Are Rather Impaired Than Disinhibition in Young Adults

PubMed Central

Kimmig, Ann-Christin S.; Andringa, Gerda; Derntl, Birgit

2018-01-01

The increasing trend of mass shootings, which were associated with excessive use of violent video games, fueled the debate of possible effects violent video games may have on adolescents and young adults. The aim of this study was to investigate the possible link between violent video gaming effects and the disposition of adverse behavior traits such as interpersonal-affective deficits and disinhibition. Data of 167 young adults, collected by an online questionnaire battery, were analyzed for lifetime video game exposure differences (i.e., non-gamers, non-violent video gamers, stopped violent video game users, and ongoing violent video game users) as well as for recent exposure effects on adverse behavior traits (Levenson’s Psychopathy Scale), while controlling for other potentially confounding lifestyle factors. While interpersonal-affective deficits were significantly higher in participants with ongoing violent video game exposure compared to non-gamers and non-violent video gamers, disinhibition was significantly higher in both – stopped and ongoing – violent video game exposure groups compared to non-gamers. Recent violent video game exposure was a stronger predictor for interpersonal-affective deficits, but was also significant for disinhibition. Considering that we observed small to medium effects in a sample of young adults with little to moderate use of violent video games highlights the importance of further investigating the potential adverse effects of violent video games on quality of social relationships. PMID:29867689

Potential Adverse Effects of Violent Video Gaming: Interpersonal- Affective Traits Are Rather Impaired Than Disinhibition in Young Adults.

PubMed

Kimmig, Ann-Christin S; Andringa, Gerda; Derntl, Birgit

2018-01-01

The increasing trend of mass shootings, which were associated with excessive use of violent video games, fueled the debate of possible effects violent video games may have on adolescents and young adults. The aim of this study was to investigate the possible link between violent video gaming effects and the disposition of adverse behavior traits such as interpersonal-affective deficits and disinhibition. Data of 167 young adults, collected by an online questionnaire battery, were analyzed for lifetime video game exposure differences (i.e., non-gamers, non-violent video gamers, stopped violent video game users, and ongoing violent video game users) as well as for recent exposure effects on adverse behavior traits (Levenson's Psychopathy Scale), while controlling for other potentially confounding lifestyle factors. While interpersonal-affective deficits were significantly higher in participants with ongoing violent video game exposure compared to non-gamers and non-violent video gamers, disinhibition was significantly higher in both - stopped and ongoing - violent video game exposure groups compared to non-gamers. Recent violent video game exposure was a stronger predictor for interpersonal-affective deficits, but was also significant for disinhibition. Considering that we observed small to medium effects in a sample of young adults with little to moderate use of violent video games highlights the importance of further investigating the potential adverse effects of violent video games on quality of social relationships.

Flexible Macroblock Ordering for Context-Aware Ultrasound Video Transmission over Mobile WiMAX

PubMed Central

Martini, Maria G.; Hewage, Chaminda T. E. R.

2010-01-01

The most recent network technologies are enabling a variety of new applications, thanks to the provision of increased bandwidth and better management of Quality of Service. Nevertheless, telemedical services involving multimedia data are still lagging behind, due to the concern of the end users, that is, clinicians and also patients, about the low quality provided. Indeed, emerging network technologies should be appropriately exploited by designing the transmission strategy focusing on quality provision for end users. Stemming from this principle, we propose here a context-aware transmission strategy for medical video transmission over WiMAX systems. Context, in terms of regions of interest (ROI) in a specific session, is taken into account for the identification of multiple regions of interest, and compression/transmission strategies are tailored to such context information. We present a methodology based on H.264 medical video compression and Flexible Macroblock Ordering (FMO) for ROI identification. Two different unequal error protection methodologies, providing higher protection to the most diagnostically relevant data, are presented. PMID:20827292

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.

Habitat connectivity as a metric for aquatic microhabitat quality: Application to Chinook salmon spawning habitat

Treesearch

Ryan Carnie; Daniele Tonina; Jim McKean; Daniel Isaak

2016-01-01

Quality of fish habitat at the scale of a single fish, at the metre resolution, which we defined here as microhabitat, has been primarily evaluated on short reaches, and their results have been extended through long river segments with methods that do not account for connectivity, a measure of the spatial distribution of habitat patches. However, recent...

Teaching Goes On: Assessment Models and the Case of an Internally Displaced Higher Education Institution in the Somali Republic

ERIC Educational Resources Information Center

Nur, Yusuf Ahmed; Grabner-Hagen, Melissa; Saam, Julie Reinhardt

2013-01-01

The metric for assessing the quality of a university within a traditional Western setting is well established. Evaluation of higher education institutions within developing countries, however, is not as clear-cut. In this paper the efficacy of quality assessment measures are examined through the case study of a university in the Somali Republic,…

An efficient approach for video information retrieval

NASA Astrophysics Data System (ADS)

Dong, Daoguo; Xue, Xiangyang

2005-01-01

Today, more and more video information can be accessed through internet, satellite, etc.. Retrieving specific video information from large-scale video database has become an important and challenging research topic in the area of multimedia information retrieval. In this paper, we introduce a new and efficient index structure OVA-File, which is a variant of VA-File. In OVA-File, the approximations close to each other in data space are stored in close positions of the approximation file. The benefit is that only a part of approximations close to the query vector need to be visited to get the query result. Both shot query algorithm and video clip algorithm are proposed to support video information retrieval efficiently. The experimental results showed that the queries based on OVA-File were much faster than that based on VA-File with small loss of result quality.

China Report, Political, Sociological and Military Affairs.

DTIC Science & Technology

1985-07-25

increase in televisions and video tapes in the 1980’s. "We have to face the challenge by improving quality," writes Yuan Wenshu, vice-chairman of the...are healthy and useful may be restored after approval has been granted. All video cassettes must be inspected and only those which are really...healthy and useful may be used in a broadcasting program. Third, all dance halls, video cassette shows and "prize-oriented games" will be operated by the

Multiple Generations on Video Tape Recorders.

ERIC Educational Resources Information Center

Wiens, Jacob H.

Helical scan video tape recorders were tested for their dubbing characteristics in order to make selection data available to media personnel. The equipment, two recorders of each type tested, was submitted by the manufacturers. The test was designed to produce quality evaluations for three generations of a single tape, thereby encompassing all…

HEVC optimizations for medical environments

NASA Astrophysics Data System (ADS)

Fernández, D. G.; Del Barrio, A. A.; Botella, Guillermo; García, Carlos; Meyer-Baese, Uwe; Meyer-Baese, Anke

2016-05-01

HEVC/H.265 is the most interesting and cutting-edge topic in the world of digital video compression, allowing to reduce by half the required bandwidth in comparison with the previous H.264 standard. Telemedicine services and in general any medical video application can benefit from the video encoding advances. However, the HEVC is computationally expensive to implement. In this paper a method for reducing the HEVC complexity in the medical environment is proposed. The sequences that are typically processed in this context contain several homogeneous regions. Leveraging these regions, it is possible to simplify the HEVC flow while maintaining a high-level quality. In comparison with the HM16.2 standard, the encoding time is reduced up to 75%, with a negligible quality loss. Moreover, the algorithm is straightforward to implement in any hardware platform.

Body worn camera

NASA Astrophysics Data System (ADS)

Aishwariya, A.; Pallavi Sudhir, Gulavani; Garg, Nemesa; Karthikeyan, B.

2017-11-01

A body worn camera is small video camera worn on the body, typically used by police officers to record arrests, evidence from crime scenes. It helps preventing and resolving complaints brought by members of the public; and strengthening police transparency, performance, and accountability. The main constants of this type of the system are video format, resolution, frames rate, and audio quality. This system records the video in .mp4 format with 1080p resolution and 30 frames per second. One more important aspect to while designing this system is amount of power the system requires as battery management becomes very critical. The main design challenges are Size of the Video, Audio for the video. Combining both audio and video and saving it in .mp4 format, Battery, size that is required for 8 hours of continuous recording, Security. For prototyping this system is implemented using Raspberry Pi model B.

Comparison of H.265/HEVC encoders

NASA Astrophysics Data System (ADS)

Trochimiuk, Maciej

2016-09-01

The H.265/HEVC is the state-of-the-art video compression standard, which allows the bitrate reduction up to 50% compared with its predecessor, H.264/AVC, maintaining equal perceptual video quality. The growth in coding efficiency was achieved by increasing the number of available intra- and inter-frame prediction features and improvements in existing ones, such as entropy encoding and filtering. Nevertheless, to achieve real-time performance of the encoder, simplifications in algorithm are inevitable. Some features and coding modes shall be skipped, to reduce time needed to evaluate modes forwarded to rate-distortion optimisation. Thus, the potential acceleration of the encoding process comes at the expense of coding efficiency. In this paper, a trade-off between video quality and encoding speed of various H.265/HEVC encoders is discussed.

Metric Evaluation Pipeline for 3d Modeling of Urban Scenes

NASA Astrophysics Data System (ADS)

Bosch, M.; Leichtman, A.; Chilcott, D.; Goldberg, H.; Brown, M.

2017-05-01

Publicly available benchmark data and metric evaluation approaches have been instrumental in enabling research to advance state of the art methods for remote sensing applications in urban 3D modeling. Most publicly available benchmark datasets have consisted of high resolution airborne imagery and lidar suitable for 3D modeling on a relatively modest scale. To enable research in larger scale 3D mapping, we have recently released a public benchmark dataset with multi-view commercial satellite imagery and metrics to compare 3D point clouds with lidar ground truth. We now define a more complete metric evaluation pipeline developed as publicly available open source software to assess semantically labeled 3D models of complex urban scenes derived from multi-view commercial satellite imagery. Evaluation metrics in our pipeline include horizontal and vertical accuracy and completeness, volumetric completeness and correctness, perceptual quality, and model simplicity. Sources of ground truth include airborne lidar and overhead imagery, and we demonstrate a semi-automated process for producing accurate ground truth shape files to characterize building footprints. We validate our current metric evaluation pipeline using 3D models produced using open source multi-view stereo methods. Data and software is made publicly available to enable further research and planned benchmarking activities.

Video techniques and data compared with observation in emergency trauma care

PubMed Central

Mackenzie, C; Xiao, Y

2003-01-01

Video recording is underused in improving patient safety and understanding performance shaping factors in patient care. We report our experience of using video recording techniques in a trauma centre, including how to gain cooperation of clinicians for video recording of their workplace performance, identify strengths of video compared with observation, and suggest processes for consent and maintenance of confidentiality of video records. Video records are a rich source of data for documenting clinician performance which reveal safety and systems issues not identified by observation. Emergency procedures and video records of critical events identified patient safety, clinical, quality assurance, systems failures, and ergonomic issues. Video recording is a powerful feedback and training tool and provides a reusable record of events that can be repeatedly reviewed and used as research data. It allows expanded analyses of time critical events, trauma resuscitation, anaesthesia, and surgical tasks. To overcome some of the key obstacles in deploying video recording techniques, researchers should (1) develop trust with video recorded subjects, (2) obtain clinician participation for introduction of a new protocol or line of investigation, (3) report aggregated video recorded data and use clinician reviews for feedback on covert processes and cognitive analyses, and (4) involve multidisciplinary experts in medicine and nursing. PMID:14645896

The effect of interference on delta modulation encoded video signals

NASA Technical Reports Server (NTRS)

Schilling, D. L.

1979-01-01

An adaptive delta modulator which encodes composite color video signals was shown to provide a good response when operating at 16 Mb/s and near-commercial quality at 23Mb/s. The ADM was relatively immune to channel errors. The system design is discussed and circuit diagrams are included.

Watermarking textures in video games

NASA Astrophysics Data System (ADS)

Liu, Huajian; Berchtold, Waldemar; Schäfer, Marcel; Lieb, Patrick; Steinebach, Martin

2014-02-01

Digital watermarking is a promising solution to video game piracy. In this paper, based on the analysis of special challenges and requirements in terms of watermarking textures in video games, a novel watermarking scheme for DDS textures in video games is proposed. To meet the performance requirements in video game applications, the proposed algorithm embeds the watermark message directly in the compressed stream in DDS files and can be straightforwardly applied in watermark container technique for real-time embedding. Furthermore, the embedding approach achieves high watermark payload to handle collusion secure fingerprinting codes with extreme length. Hence, the scheme is resistant to collusion attacks, which is indispensable in video game applications. The proposed scheme is evaluated in aspects of transparency, robustness, security and performance. Especially, in addition to classical objective evaluation, the visual quality and playing experience of watermarked games is assessed subjectively in game playing.

Packetized video on MAGNET

NASA Astrophysics Data System (ADS)

Lazar, Aurel A.; White, John S.

1986-11-01

Theoretical analysis of an ILAN model of MAGNET, an integrated network testbed developed at Columbia University, shows that the bandwidth freed up by video and voice calls during periods of little movement in the images and silence periods in the speech signals could be utilized efficiently for graphics and data transmission. Based on these investigations, an architecture supporting adaptive protocols that are dynamically controlled by the requirements of a fluctuating load and changing user environment has been advanced. To further analyze the behavior of the network, a real-time packetized video system has been implemented. This system is embedded in the real time multimedia workstation EDDY that integrates video, voice and data traffic flows. Protocols supporting variable bandwidth, constant quality packetized video transport are descibed in detail.

Packetized Video On MAGNET

NASA Astrophysics Data System (ADS)

Lazar, Aurel A.; White, John S.

1987-07-01

Theoretical analysis of integrated local area network model of MAGNET, an integrated network testbed developed at Columbia University, shows that the bandwidth freed up during video and voice calls during periods of little movement in the images and periods of silence in the speech signals could be utilized efficiently for graphics and data transmission. Based on these investigations, an architecture supporting adaptive protocols that are dynamicaly controlled by the requirements of a fluctuating load and changing user environment has been advanced. To further analyze the behavior of the network, a real-time packetized video system has been implemented. This system is embedded in the real-time multimedia workstation EDDY, which integrates video, voice, and data traffic flows. Protocols supporting variable-bandwidth, fixed-quality packetized video transport are described in detail.

An investigation of automatic exposure control calibration for chest imaging with a computed radiography system.

PubMed

Moore, C S; Wood, T J; Avery, G; Balcam, S; Needler, L; Beavis, A W; Saunderson, J R

2014-05-07

The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean effective noise equivalent quanta (eNEQm), all measured using a uniform chest phantom. Subsequent calibration curves were derived to ensure each metric was held constant across the tube voltage range. Each curve was assessed for its clinical appropriateness by generating computer simulated chest images with correct detector air kermas for each tube voltage, and grading these against reference images which were reconstructed at detector air kermas correct for the constant detector dose indicator (DDI) curve currently programmed into the AEC device. All simulated chest images contained clinically realistic projected anatomy and anatomical noise and were scored by experienced image evaluators. Constant DDI and CNR curves do not appear to provide optimized performance across the diagnostic energy range. Conversely, constant eNEQm and SNR do appear to provide optimized performance, with the latter being the preferred calibration metric given as it is easier to measure in practice. Medical physicists may use the SNR image quality metric described here when setting up and optimizing AEC devices for chest radiography CR systems with a degree of confidence that resulting clinical image quality will be adequate for the required clinical task. However, this must be done with close cooperation of expert image evaluators, to ensure appropriate levels of detector air kerma.

An investigation of automatic exposure control calibration for chest imaging with a computed radiography system

NASA Astrophysics Data System (ADS)

Moore, C. S.; Wood, T. J.; Avery, G.; Balcam, S.; Needler, L.; Beavis, A. W.; Saunderson, J. R.

2014-05-01

The purpose of this study was to examine the use of three physical image quality metrics in the calibration of an automatic exposure control (AEC) device for chest radiography with a computed radiography (CR) imaging system. The metrics assessed were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and mean effective noise equivalent quanta (eNEQm), all measured using a uniform chest phantom. Subsequent calibration curves were derived to ensure each metric was held constant across the tube voltage range. Each curve was assessed for its clinical appropriateness by generating computer simulated chest images with correct detector air kermas for each tube voltage, and grading these against reference images which were reconstructed at detector air kermas correct for the constant detector dose indicator (DDI) curve currently programmed into the AEC device. All simulated chest images contained clinically realistic projected anatomy and anatomical noise and were scored by experienced image evaluators. Constant DDI and CNR curves do not appear to provide optimized performance across the diagnostic energy range. Conversely, constant eNEQm and SNR do appear to provide optimized performance, with the latter being the preferred calibration metric given as it is easier to measure in practice. Medical physicists may use the SNR image quality metric described here when setting up and optimizing AEC devices for chest radiography CR systems with a degree of confidence that resulting clinical image quality will be adequate for the required clinical task. However, this must be done with close cooperation of expert image evaluators, to ensure appropriate levels of detector air kerma.

A software quality model and metrics for risk assessment

NASA Technical Reports Server (NTRS)

Hyatt, L.; Rosenberg, L.

1996-01-01

A software quality model and its associated attributes are defined and used as the model for the basis for a discussion on risk. Specific quality goals and attributes are selected based on their importance to a software development project and their ability to be quantified. Risks that can be determined by the model's metrics are identified. A core set of metrics relating to the software development process and its products is defined. Measurements for each metric and their usability and applicability are discussed.

Dynamic resource allocation engine for cloud-based real-time video transcoding in mobile cloud computing environments

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.

Video streaming in nursing education: bringing life to online education.

PubMed

Smith-Stoner, Marilyn; Willer, Ann

2003-01-01

Distance education is a standard form of instruction for many colleges of nursing. Web-based course and program content has been delivered primarily through text-based presentations such as PowerPoint slides and Web search activities. However, the rapid pace of technological innovation is making available more sophisticated forms of delivery such as video streaming. High-quality video streams, created at the instructor's desktop or in basic recording studios, can be produced that build on PowerPoint or create new media for use on the Web. The technology required to design, produce, and upload short video-streamed course content objects to the Internet is described. The preparation of materials, suggested production guidelines, and examples of information presented via desktop video methods are presented.

Qualitative Video Analysis of Track-Cycling Team Pursuit in World-Class Athletes.

PubMed

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.

Enhanced protocol for real-time transmission of echocardiograms over wireless channels.

PubMed

Cavero, Eva; Alesanco, Alvaro; García, Jose

2012-11-01

This paper presents a methodology to transmit clinical video over wireless networks in real-time. A 3-D set partitioning in hierarchical trees compression prior to transmission is proposed. In order to guarantee the clinical quality of the compressed video, a clinical evaluation specific to each video modality has to be made. This evaluation indicates the minimal transmission rate necessary for an accurate diagnosis. However, the channel conditions produce errors and distort the video. A reliable application protocol is therefore proposed using a hybrid solution in which either retransmission or retransmission combined with forward error correction (FEC) techniques are used, depending on the channel conditions. In order to analyze the proposed methodology, the 2-D mode of an echocardiogram has been assessed. A bandwidth of 200 kbps is necessary to guarantee its clinical quality. The transmission using the proposed solution and retransmission and FEC techniques working separately have been simulated and compared in high-speed uplink packet access (HSUPA) and worldwide interoperability for microwave access (WiMAX) networks. The proposed protocol achieves guaranteed clinical quality for bit error rates higher than with the other protocols, being for a mobile speed of 60 km/h up to 3.3 times higher for HSUPA and 10 times for WiMAX.

Architecture and protocol of a semantic system designed for video tagging with sensor data in mobile devices.

PubMed

Macias, Elsa; Lloret, Jaime; Suarez, Alvaro; Garcia, Miguel

2012-01-01

Current mobile phones come with several sensors and powerful video cameras. These video cameras can be used to capture good quality scenes, which can be complemented with the information gathered by the sensors also embedded in the phones. For example, the surroundings of a beach recorded by the camera of the mobile phone, jointly with the temperature of the site can let users know via the Internet if the weather is nice enough to swim. In this paper, we present a system that tags the video frames of the video recorded from mobile phones with the data collected by the embedded sensors. The tagged video is uploaded to a video server, which is placed on the Internet and is accessible by any user. The proposed system uses a semantic approach with the stored information in order to make easy and efficient video searches. Our experimental results show that it is possible to tag video frames in real time and send the tagged video to the server with very low packet delay variations. As far as we know there is not any other application developed as the one presented in this paper.

Architecture and Protocol of a Semantic System Designed for Video Tagging with Sensor Data in Mobile Devices

PubMed Central

Macias, Elsa; Lloret, Jaime; Suarez, Alvaro; Garcia, Miguel

2012-01-01

Current mobile phones come with several sensors and powerful video cameras. These video cameras can be used to capture good quality scenes, which can be complemented with the information gathered by the sensors also embedded in the phones. For example, the surroundings of a beach recorded by the camera of the mobile phone, jointly with the temperature of the site can let users know via the Internet if the weather is nice enough to swim. In this paper, we present a system that tags the video frames of the video recorded from mobile phones with the data collected by the embedded sensors. The tagged video is uploaded to a video server, which is placed on the Internet and is accessible by any user. The proposed system uses a semantic approach with the stored information in order to make easy and efficient video searches. Our experimental results show that it is possible to tag video frames in real time and send the tagged video to the server with very low packet delay variations. As far as we know there is not any other application developed as the one presented in this paper. PMID:22438753

Video Monitoring a Simulation-Based Quality Improvement Program in Bihar, India.

PubMed

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.

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.

Intubation Success in Critical Care Transport: A Multicenter Study.

PubMed

Reichert, Ryan J; Gothard, Megan; Gothard, M David; Schwartz, Hamilton P; Bigham, Michael T

2018-02-21

Tracheal intubation (TI) is a lifesaving critical care skill. Failed TI attempts, however, can harm patients. Critical care transport (CCT) teams function as the first point of critical care contact for patients being transported to tertiary medical centers for specialized surgical, medical, and trauma care. The Ground and Air Medical qUality in Transport (GAMUT) Quality Improvement Collaborative uses a quality metric database to track CCT quality metric performance, including TI. We sought to describe TI among GAMUT participants with the hypothesis that CCT would perform better than other prehospital TI reports and similarly to hospital TI success. The GAMUT Database is a global, voluntary database for tracking consensus quality metric performance among CCT programs performing neonatal, pediatric, and adult transports. The TI-specific quality metrics are "first attempt TI success" and "definitive airway sans hypoxia/hypotension on first attempt (DASH-1A)." The 2015 GAMUT Database was queried and analysis included patient age, program type, and intubation success rate. Analysis included simple statistics and Pearson chi-square with Bonferroni-adjusted post hoc z tests (significance = p < 0.05 via two-sided testing). Overall, 85,704 patient contacts (neonatal n [%] = 12,664 [14.8%], pediatric n [%] = 28,992 [33.8%], adult n [%] = 44,048 [51.4%]) were included, with 4,036 (4.7%) TI attempts. First attempt TI success was lowest in neonates (59.3%, 617 attempts), better in pediatrics (81.7%, 519 attempts), and best in adults (87%, 2900 attempts), p < 0.001. Adult-focused CCT teams had higher overall first attempt TI success versus pediatric- and neonatal-focused teams (86.9% vs. 63.5%, p < 0.001) and also in pediatric first attempt TI success (86.5% vs. 75.3%, p < 0.001). DASH-1A rates were lower across all patient types (neonatal = 51.9%, pediatric = 74.3%, adult = 79.8%). CCT TI is not uncommon, and rates of TI and DASH-1A success are higher in adult patients and adult-focused CCT teams. TI success rates are higher in CCT than other prehospital settings, but lower than in-hospital success TI rates. Identifying factors influencing TI success among high performers should influence best practice strategies for TI.

Mobile Video in Everyday Social Interactions

NASA Astrophysics Data System (ADS)

Reponen, Erika; Lehikoinen, Jaakko; Impiö, Jussi

Video recording has become a spontaneous everyday activity for many people, thanks to the video capabilities of modern mobile phones. Internet connectivity of mobile phones enables fluent sharing of captured material even real-time, which makes video an up-and-coming everyday interaction medium. In this article we discuss the effect of the video camera in the social environment, everyday life situations, mainly based on a study where four groups of people used digital video cameras in their normal settings. We also reflect on another study of ours, relating to real-time mobile video communication and discuss future views. The aim of our research is to understand the possibilities in the domain of mobile video. Live and delayed sharing seem to have their special characteristics, live video being used as a virtual window between places whereas delayed video usage has more scope for good-quality content. While this novel way of interacting via mobile video enables new social patterns, it also raises new concerns for privacy and trust between participating persons in all roles, largely due to the widely spreading possibilities of videos. Video in a social situation affects cameramen (who record), targets (who are recorded), passers-by (who are unintentionally in the situation), and the audience (who follow the videos or recording situations) but also the other way around, the participants affect the video by their varying and evolving personal and communicational motivations for recording.

The quality of veterinary in-clinic and reference laboratory biochemical testing.

PubMed

Rishniw, Mark; Pion, Paul D; Maher, Tammy

2012-03-01

Although evaluation of biochemical analytes in blood is common in veterinary practice, studies assessing the global quality of veterinary in-clinic and reference laboratory testing have not been reported. The aim of this study was to assess the quality of biochemical testing in veterinary laboratories using results obtained from analyses of 3 levels of assayed quality control materials over 5 days. Quality was assessed by comparison of calculated total error with quality requirements, determination of sigma metrics, use of a quality goal index to determine factors contributing to poor performance, and agreement between in-clinic and reference laboratory mean results. The suitability of in-clinic and reference laboratory instruments for statistical quality control was determined using adaptations from the computerized program, EZRules3. Reference laboratories were able to achieve desirable quality requirements more frequently than in-clinic laboratories. Across all 3 materials, > 50% of in-clinic analyzers achieved a sigma metric ≥ 6.0 for measurement of 2 analytes, whereas > 50% of reference laboratory analyzers achieved a sigma metric ≥ 6.0 for measurement of 6 analytes. Expanded uncertainty of measurement and ± total allowable error resulted in the highest mean percentages of analytes demonstrating agreement between in-clinic and reference laboratories. Owing to marked variation in bias and coefficient of variation between analyzers of the same and different types, the percentages of analytes suitable for statistical quality control varied widely. These findings reflect the current state-of-the-art with regard to in-clinic and reference laboratory analyzer performance and provide a baseline for future evaluations of the quality of veterinary laboratory testing. © 2012 American Society for Veterinary Clinical Pathology.

Six Sigma arises from the ashes of TQM with a twist.

PubMed

Black, Ken; Revere, Lee

2006-01-01

This paper sets out to analyse the use of the Six Sigma methodology to improve quality in healthcare. It looks at how Six Sigma grew out of the concept of Total Quality Management (TQM). Six Sigma is a quality improvement methodology that has been widely adopted by companies since the early 1990s and has grown exponentially in the healthcare industry during the past five years. Some of the main tenets of Six Sigma have emerged from the principles of TQM, including the notion that the entire organization must support the quality effort; that there should be a vigorous education effort; and that a quality improvement process should emphasize root cause analysis. In spite of its early success, TQM "crashed and burned" for several reasons including the fact that financial benefits were difficult to assign to TQM efforts, root cause was not always determined resulting in recurring errors, there was no common metric to measure the level of quality attained, and quality efforts were sometimes aimed at processes or operations that were not critical to the customer. Six Sigma filled the vacuums created by these TQM failures in several ways. Under the Six Sigma methodology, quality improvement projects are carefully defined so that they can be successfully completed within a relatively short time frame. Financials are applied to each completed project so that management knows how much the project saves the institution. On each project, intense study is used to determine root cause analysis; and in the end, a metric known as "sigma level" can be assigned to signify the level of quality. Six Sigma has a "critical to quality" dimension that keeps the quality effort focused on improving only those things that really matter to the customer.

Performance analysis of medical video streaming over mobile WiMAX.

PubMed

Alinejad, Ali; Philip, N; Istepanian, R H

2010-01-01

Wireless medical ultrasound streaming is considered one of the emerging application within the broadband mobile healthcare domain. These applications are considered as bandwidth demanding services that required high data rates with acceptable diagnostic quality of the transmitted medical images. In this paper, we present the performance analysis of a medical ultrasound video streaming acquired via special robotic ultrasonography system over emulated WiMAX wireless network. The experimental set-up of this application is described together with the performance of the relevant medical quality of service (m-QoS) metrics.

12. NBS LOWER ROOM. BEHIND FAR GLASS WALL IS VIDEO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. NBS LOWER ROOM. BEHIND FAR GLASS WALL IS VIDEO TAPE EQUIPMENT AND VOICE INTERCOM EQUIPMENT. THE MONITORS ABOVE GLASS WALL DISPLAY UNDERWATER TEST VIDEO TO CONTROL ROOM. FARTHEST CONSOLE ROW CONTAINS CAMERA SWITCHING, PANNING, TILTING, FOCUSING, AND ZOOMING. MIDDLE CONSOLE ROW CONTAINS TEST CONDUCTOR CONSOLES FOR MONITORING TEST ACTIVITIES AND DATA. THE CLOSEST CONSOLE ROW IS NBS FACILITY CONSOLES FOR TEST DIRECTOR, SAFETY AND QUALITY ASSURANCE REPRESENTATIVES. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

13. NBS LOWER ROOM. BEHIND FAR GLASS WALL IS VIDEO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. NBS LOWER ROOM. BEHIND FAR GLASS WALL IS VIDEO TAPE EQUIPMENT AND VOICE INTERCOM EQUIPMENT. THE MONITORS ABOVE GLASS WALL DISPLAY UNDERWATER TEST VIDEO TO CONTROL ROOM. FARTHEST CONSOLE ROW CONTAINS CAMERA SWITCHING, PANNING, TILTING, FOCUSING, AND ZOOMING. MIDDLE CONSOLE ROW CONTAINS TEST CONDUCTOR CONSOLES FOR MONITORING TEST ACTIVITIES AND DATA. THE CLOSEST CONSOLE ROW IS NBC FACILITY CONSOLES FOR TEST DIRECTOR, SAFETY AND QUALITY ASSURANCE REPRESENTATIVES. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

Rapid production of optimal-quality reduced-resolution representations of very large databases

DOEpatents

Sigeti, David E.; Duchaineau, Mark; Miller, Mark C.; Wolinsky, Murray; Aldrich, Charles; Mineev-Weinstein, Mark B.

2001-01-01

View space representation data is produced in real time from a world space database representing terrain features. The world space database is first preprocessed. A database is formed having one element for each spatial region corresponding to a finest selected level of detail. A multiresolution database is then formed by merging elements and a strict error metric is computed for each element at each level of detail that is independent of parameters defining the view space. The multiresolution database and associated strict error metrics are then processed in real time for real time frame representations. View parameters for a view volume comprising a view location and field of view are selected. The error metric with the view parameters is converted to a view-dependent error metric. Elements with the coarsest resolution are chosen for an initial representation. Data set first elements from the initial representation data set are selected that are at least partially within the view volume. The first elements are placed in a split queue ordered by the value of the view-dependent error metric. If the number of first elements in the queue meets or exceeds a predetermined number of elements or whether the largest error metric is less than or equal to a selected upper error metric bound, the element at the head of the queue is force split and the resulting elements are inserted into the queue. Force splitting is continued until the determination is positive to form a first multiresolution set of elements. The first multiresolution set of elements is then outputted as reduced resolution view space data representing the terrain features.

Portable low-cost devices for videotaping, editing, and displaying field-sequential stereoscopic motion pictures and video

NASA Astrophysics Data System (ADS)

Starks, Michael R.

1990-09-01

A variety of low cost devices for capturing, editing and displaying field sequential 60 cycle stereoscopic video have recently been marketed by 3D TV Corp. and others. When properly used, they give very high quality images with most consumer and professional equipment. Our stereoscopic multiplexers for creating and editing field sequential video in NTSC or component(SVHS, Betacain, RGB) and Home 3D Theater system employing LCD eyeglasses have made 3D movies and television available to a large audience.

The protective role of general self-determination against 'thin ideal' media exposure on women's body image and eating-related concerns.

PubMed

Mask, Lisa; Blanchard, Céline M

2011-04-01

Women's responses to 'thin ideal' media pending their level of general self-determination (GSD) were examined. High and low GSD women (N = 99) viewed a 'thin physique salient' (TPS) video or a 'thin physique non-salient' (TPNS) video. Following exposure to the TPS video, perceptions of pressure from the media to be thin, body dissatisfaction, and concerns over quantity of food were greater for low but not high GSD women. However, high GSD women reported greater concerns over the quality of food they eat following exposure to the TPNS video. Prevention efforts aimed at enhancing GSD are discussed.

Mechanistic Sediment Quality Guidelines Based on Contaminant Bioavailability: Equilibrium Partitioning Sediment Benchmarks

EPA Science Inventory

Globally, billions of metric tons of contaminated sediments are present in aquatic systems representing a potentially significant ecological risk. Estimated costs to manage (i.e., remediate and monitor) these sediments are in the billions of U.S. dollars. Biologically-based app...

[Video-based self-control in surgical teaching. A new tool in a new concept].

PubMed

Dahmen, U; Sänger, C; Wurst, C; Arlt, J; Wei, W; Dondorf, F; Richter, B; Settmacher, U; Dirsch, O

2013-10-01

Image and video-based results and process control are essential tools of a new teaching concept for conveying surgical skills. The new teaching concept integrates approved teaching principles and new media. Every performance of exercises is videotaped and the result photographically recorded. The quality of the process and result becomes accessible for an analysis by the teacher and the student/learner. The learner is instructed to perform a criteria-based self-analysis of the video and image material by themselves. The new learning concept has so far been successfully applied in seven rounds within the newly designed modular class "Intensivkurs Chirurgische Techniken" (Intensive training of surgical techniques). Result documentation and analysis via digital picture was completed by almost every student. The quality of the results was high. Interestingly the result quality did not correlate with the time needed for the exercise. The training success had a lasting effect. The new and elaborate concept improves the quality of teaching. In the long run resources for patient care should be saved when training students according to this concept prior to performing tasks in the operating theater. These resources should be allocated for further refining innovative teaching concepts.

Video Capture of Plastic Surgery Procedures Using the GoPro HERO 3+.

PubMed

Graves, Steven Nicholas; Shenaq, Deana Saleh; Langerman, Alexander J; Song, David H

2015-02-01

Significant improvements can be made in recoding surgical procedures, particularly in capturing high-quality video recordings from the surgeons' point of view. This study examined the utility of the GoPro HERO 3+ Black Edition camera for high-definition, point-of-view recordings of plastic and reconstructive surgery. The GoPro HERO 3+ Black Edition camera was head-mounted on the surgeon and oriented to the surgeon's perspective using the GoPro App. The camera was used to record 4 cases: 2 fat graft procedures and 2 breast reconstructions. During cases 1-3, an assistant remotely controlled the GoPro via the GoPro App. For case 4 the GoPro was linked to a WiFi remote, and controlled by the surgeon. Camera settings for case 1 were as follows: 1080p video resolution; 48 fps; Protune mode on; wide field of view; 16:9 aspect ratio. The lighting contrast due to the overhead lights resulted in limited washout of the video image. Camera settings were adjusted for cases 2-4 to a narrow field of view, which enabled the camera's automatic white balance to better compensate for bright lights focused on the surgical field. Cases 2-4 captured video sufficient for teaching or presentation purposes. The GoPro HERO 3+ Black Edition camera enables high-quality, cost-effective video recording of plastic and reconstructive surgery procedures. When set to a narrow field of view and automatic white balance, the camera is able to sufficiently compensate for the contrasting light environment of the operating room and capture high-resolution, detailed video.

Effect of tape recording on perturbation measures.

PubMed

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.

A Data Hiding Technique to Synchronously Embed Physiological Signals in H.264/AVC Encoded Video for Medicine Healthcare.

PubMed

Peña, Raul; Ávila, Alfonso; Muñoz, David; Lavariega, Juan

2015-01-01

The recognition of clinical manifestations in both video images and physiological-signal waveforms is an important aid to improve the safety and effectiveness in medical care. Physicians can rely on video-waveform (VW) observations to recognize difficult-to-spot signs and symptoms. The VW observations can also reduce the number of false positive incidents and expand the recognition coverage to abnormal health conditions. The synchronization between the video images and the physiological-signal waveforms is fundamental for the successful recognition of the clinical manifestations. The use of conventional equipment to synchronously acquire and display the video-waveform information involves complex tasks such as the video capture/compression, the acquisition/compression of each physiological signal, and the video-waveform synchronization based on timestamps. This paper introduces a data hiding technique capable of both enabling embedding channels and synchronously hiding samples of physiological signals into encoded video sequences. Our data hiding technique offers large data capacity and simplifies the complexity of the video-waveform acquisition and reproduction. The experimental results revealed successful embedding and full restoration of signal's samples. Our results also demonstrated a small distortion in the video objective quality, a small increment in bit-rate, and embedded cost savings of -2.6196% for high and medium motion video sequences.

Development and application of a soil organic matter-based soil quality index in mineralized terrane of the Western US

Treesearch

S. W. Blecker; L. L. Stillings; M. C. Amacher; J. A. Ippolito; N. M. DeCrappeo

2012-01-01

Soil quality indices provide a means of distilling large amounts of data into a single metric that evaluates the soil's ability to carry out key ecosystem functions. Primarily developed in agroecosytems, then forested ecosystems, an index using the relation between soil organic matter and other key soil properties in more semi-arid systems of the Western US...

Video Capture of Plastic Surgery Procedures Using the GoPro HERO 3+

PubMed Central

Graves, Steven Nicholas; Shenaq, Deana Saleh; Langerman, Alexander J.

2015-01-01

Background: Significant improvements can be made in recoding surgical procedures, particularly in capturing high-quality video recordings from the surgeons’ point of view. This study examined the utility of the GoPro HERO 3+ Black Edition camera for high-definition, point-of-view recordings of plastic and reconstructive surgery. Methods: The GoPro HERO 3+ Black Edition camera was head-mounted on the surgeon and oriented to the surgeon’s perspective using the GoPro App. The camera was used to record 4 cases: 2 fat graft procedures and 2 breast reconstructions. During cases 1-3, an assistant remotely controlled the GoPro via the GoPro App. For case 4 the GoPro was linked to a WiFi remote, and controlled by the surgeon. Results: Camera settings for case 1 were as follows: 1080p video resolution; 48 fps; Protune mode on; wide field of view; 16:9 aspect ratio. The lighting contrast due to the overhead lights resulted in limited washout of the video image. Camera settings were adjusted for cases 2-4 to a narrow field of view, which enabled the camera’s automatic white balance to better compensate for bright lights focused on the surgical field. Cases 2-4 captured video sufficient for teaching or presentation purposes. Conclusions: The GoPro HERO 3+ Black Edition camera enables high-quality, cost-effective video recording of plastic and reconstructive surgery procedures. When set to a narrow field of view and automatic white balance, the camera is able to sufficiently compensate for the contrasting light environment of the operating room and capture high-resolution, detailed video. PMID:25750851

The IAQ Tools for Schools Walkthrough Video: Four Schools Making a Difference. [Videotape].

ERIC Educational Resources Information Center

Environmental Protection Agency, Washington, DC.

This video illustrates one of the key components of the Environmental Protection Agency's "Indoor Air Quality Tools for Schools" (IAQ TfS) process--the school walkthrough. Videotaped at a North Carolina school built in 1999, hosts Keith Flippen and Debra Terry describe what schools in Nebraska, Massachusetts, Connecticut, and Iowa found…

ATM: Restructing Learning for Deaf Students.

ERIC Educational Resources Information Center

Keefe, Barbara; Stockford, David

Governor Baxter School for the Deaf is one of six Maine pilot sites chosen by NYNEX to showcase asynchronous transfer mode (ATM) technology. ATM is a network connection that allows high bandwidth transmission of data, voice, and video. Its high speed capability allows for high quality two-way full-motion video, which is especially beneficial to a…

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.

Evaluation of H.264 and H.265 full motion video encoding for small UAS platforms

NASA Astrophysics Data System (ADS)

McGuinness, Christopher D.; Walker, David; Taylor, Clark; Hill, Kerry; Hoffman, Marc

2016-05-01

Of all the steps in the image acquisition and formation pipeline, compression is the only process that degrades image quality. A selected compression algorithm succeeds or fails to provide sufficient quality at the requested compression rate depending on how well the algorithm is suited to the input data. Applying an algorithm designed for one type of data to a different type often results in poor compression performance. This is mostly the case when comparing the performance of H.264, designed for standard definition data, to HEVC (High Efficiency Video Coding), which the Joint Collaborative Team on Video Coding (JCT-VC) designed for high-definition data. This study focuses on evaluating how HEVC compares to H.264 when compressing data from small UAS platforms. To compare the standards directly, we assess two open-source traditional software solutions: x264 and x265. These software-only comparisons allow us to establish a baseline of how much improvement can generally be expected of HEVC over H.264. Then, specific solutions leveraging different types of hardware are selected to understand the limitations of commercial-off-the-shelf (COTS) options. Algorithmically, regardless of the implementation, HEVC is found to provide similar quality video as H.264 at 40% lower data rates for video resolutions greater than 1280x720, roughly 1 Megapixel (MPx). For resolutions less than 1MPx, H.264 is an adequate solution though a small (roughly 20%) compression boost is earned by employing HEVC. New low cost, size, weight, and power (CSWAP) HEVC implementations are being developed and will be ideal for small UAS systems.

Twins with Autism: Utilising Video Feedback to Improve Job-Related Behaviours

ERIC Educational Resources Information Center

Mackey, Megan; Nelson, Gretchen

2015-01-01

Employment for individuals with autism spectrum disorders (ASD) is a significant factor in assuring quality of life in adulthood. The research reported in this article examines the effectiveness of video feedback (VFB) in improving the job-related behaviours of twin adolescents with ASD and learning disabilities. The targeted behaviours included…

Digital Video (DV): A Primer for Developing an Enterprise Video Strategy

DTIC Science & Technology

2002-09-01

26 4. Betacam /BetacamSP ......................................................................... 26 5...an adaptor cassette to be purchased separately. 4. Betacam /BetacamSP Originally introduced by Sony in 1982, the Betacam failed to achieve the same...level of consumer adoption as VHS. Although the Betacam and its player (the Betamax) boasted greater picture and sound quality, its price

How Interactive Video (ITV) Web-Enhanced Format Affects Instructional Strategy and Instructor Satisfaction

ERIC Educational Resources Information Center

Moody, Catrina V.

2013-01-01

This qualitative study explored the quality of technology associated with interactive video (ITV) classes in distance education programs and the resulting satisfaction of the instructors teaching this format. The participants were full time instructors of a rural community college that used the ITV format. Community college ITV instructors are…

Intelligent keyframe extraction for video printing

NASA Astrophysics Data System (ADS)

Zhang, Tong

2004-10-01

Nowadays most digital cameras have the functionality of taking short video clips, with the length of video ranging from several seconds to a couple of minutes. The purpose of this research is to develop an algorithm which extracts an optimal set of keyframes from each short video clip so that the user could obtain proper video frames to print out. In current video printing systems, keyframes are normally obtained by evenly sampling the video clip over time. Such an approach, however, may not reflect highlights or regions of interest in the video. Keyframes derived in this way may also be improper for video printing in terms of either content or image quality. In this paper, we present an intelligent keyframe extraction approach to derive an improved keyframe set by performing semantic analysis of the video content. For a video clip, a number of video and audio features are analyzed to first generate a candidate keyframe set. These features include accumulative color histogram and color layout differences, camera motion estimation, moving object tracking, face detection and audio event detection. Then, the candidate keyframes are clustered and evaluated to obtain a final keyframe set. The objective is to automatically generate a limited number of keyframes to show different views of the scene; to show different people and their actions in the scene; and to tell the story in the video shot. Moreover, frame extraction for video printing, which is a rather subjective problem, is considered in this work for the first time, and a semi-automatic approach is proposed.

Frequent video-game playing in young males is associated with central adiposity and high-sugar, low-fibre dietary consumption.

PubMed

Mario, Siervo; Hannah, Cameron; Jonathan, Wells C K; Jose, Lara

2014-12-01

Video-game playing is associated with an increased obesity risk. The association of video-game playing with body composition, physical activity and eating behaviour was investigated. A total of 45 young males (age range 18-27 years, BMI range 18.5-35.1 kg/m(2)) were recruited. Measurements of body composition and blood pressure were performed. The EPIC-FFQ questionnaire was used to assess dietary intake. A questionnaire battery was administered to assess physical activity, eating behaviour, sleep quality and frequency of video-game playing (hours/week). Subjects were categorised into frequent (>7 h/week) and non-frequent (≤7 h/week) players. Frequent video-game players had greater waist circumference and fat mass. Video-game playing was significantly associated with high added sugar and low fibre consumption. A higher level of dietary restraint was observed in non-frequent video-game users. These preliminary results identify frequent video-game playing as an important lifestyle behaviour which may have important implications for understanding obesity risk in young male adults.

Looking Tasks Online: Utilizing Webcams to Collect Video Data from Home.

PubMed

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.

Six Sigma Quality Management System and Design of Risk-based Statistical Quality Control.

PubMed

Westgard, James O; Westgard, Sten A

2017-03-01

Six sigma concepts provide a quality management system (QMS) with many useful tools for managing quality in medical laboratories. This Six Sigma QMS is driven by the quality required for the intended use of a test. The most useful form for this quality requirement is the allowable total error. Calculation of a sigma-metric provides the best predictor of risk for an analytical examination process, as well as a design parameter for selecting the statistical quality control (SQC) procedure necessary to detect medically important errors. Simple point estimates of sigma at medical decision concentrations are sufficient for laboratory applications. Copyright © 2016 Elsevier Inc. All rights reserved.

Refocusing the Lens: Enhancing Elementary Special Education Reading Instruction through Video Self-Reflection

ERIC Educational Resources Information Center

Osipova, Anna; Prichard, Brooke; Boardman, Alison Gould; Kiely, Mary Theresa; Carroll, Patricia E.

2011-01-01

This article presents the findings from a pilot study exploring the use of video as a self-reflection tool combined with high-quality, collaborative professional development (PD). Participants were in-service, upper-elementary, special education instructors teaching word study and fluency to students with learning disabilities. Participants…

Use of streamed internet video for cytology training and education: www.PathLab.org.

PubMed

Poller, David; Ljung, Britt-Marie; Gonda, Peter

2009-05-01

An Internet-based method is described for submission of video clips to a website editor to be reviewed, edited, and then uploaded onto a video server, with a hypertext link to a website. The information on the webpages is searchable via the website sitemap on Internet search engines. A survey of video users who accessed a single 59-minute FNA cytology training cytology video via the website showed a mean score for usefulness for specialists/consultants of 3.75, range 1-5, n = 16, usefulness for trainees mean score was 4.4, range 3-5, n = 12, with a mean score for visual and sound quality of 3.9, range 2-5, n = 16. Fifteen out of 17 respondents thought that posting video training material on the Internet was a good idea, and 9 of 17 respondents would also consider submitting training videos to a similar website. This brief exercise has shown that there is value in posting educational or training video content on the Internet and that the use of streamed video accessed via the Internet will be of increasing importance. (c) 2009 Wiley-Liss, Inc.