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.

How much crosstalk can be allowed in a stereoscopic system at various grey levels?

NASA Astrophysics Data System (ADS)

Shestak, Sergey; Kim, Daesik; Kim, Yongie

2012-03-01

We have calculated a perceptual threshold of stereoscopic crosstalk on the basis of mathematical model of human vision sensitivity. Instead of linear model of just noticeable difference (JND) known as Weber's law we applied nonlinear Barten's model. The predicted crosstalk threshold varies with the background luminance. The calculated values of threshold are in a reasonable agreement with known experimental data. We calculated perceptual threshold of crosstalk for various combinations of the applied grey level. This result can be applied for the assessment of grey-to-grey crosstalk compensation. Further computational analysis of the applied model predicts the increase of the displayable image contrast with reduction of the maximum displayable luminance.

Compression of stereoscopic video using MPEG-2

NASA Astrophysics Data System (ADS)

Puri, A.; Kollarits, Richard V.; Haskell, Barry G.

1995-10-01

Many current as well as emerging applications in areas of entertainment, remote operations, manufacturing industry and medicine can benefit from the depth perception offered by stereoscopic video systems which employ two views of a scene imaged under the constraints imposed by human visual system. Among the many challenges to be overcome for practical realization and widespread use of 3D/stereoscopic systems are good 3D displays and efficient techniques for digital compression of enormous amounts of data while maintaining compatibility with normal video decoding and display systems. After a brief introduction to the basics of 3D/stereo including issues of depth perception, stereoscopic 3D displays and terminology in stereoscopic imaging and display, we present an overview of tools in the MPEG-2 video standard that are relevant to our discussion on compression of stereoscopic video, which is the main topic of this paper. Next, we outilne the various approaches for compression of stereoscopic video and then focus on compatible stereoscopic video coding using MPEG-2 Temporal scalability concepts. Compatible coding employing two different types of prediction structures become potentially possible, disparity compensated prediction and combined disparity and motion compensated predictions. To further improve coding performance and display quality, preprocessing for reducing mismatch between the two views forming stereoscopic video is considered. Results of simulations performed on stereoscopic video of normal TV resolution are then reported comparing the performance of two prediction structures with the simulcast solution. It is found that combined disparity and motion compensated prediction offers the best performance. Results indicate that compression of both views of stereoscopic video of normal TV resolution appears feasible in a total of 6 to 8 Mbit/s. We then discuss regarding multi-viewpoint video, a generalization of stereoscopic video. Finally, we describe ongoing efforts within MPEG-2 to define a profile for stereoscopic video coding, as well as, the promise of MPEG-4 in addressing coding of multi-viewpoint video.

Compression of stereoscopic video using MPEG-2

NASA Astrophysics Data System (ADS)

Puri, Atul; Kollarits, Richard V.; Haskell, Barry G.

1995-12-01

Many current as well as emerging applications in areas of entertainment, remote operations, manufacturing industry and medicine can benefit from the depth perception offered by stereoscopic video systems which employ two views of a scene imaged under the constraints imposed by human visual system. Among the many challenges to be overcome for practical realization and widespread use of 3D/stereoscopic systems are good 3D displays and efficient techniques for digital compression of enormous amounts of data while maintaining compatibility with normal video decoding and display systems. After a brief introduction to the basics of 3D/stereo including issues of depth perception, stereoscopic 3D displays and terminology in stereoscopic imaging and display, we present an overview of tools in the MPEG-2 video standard that are relevant to our discussion on compression of stereoscopic video, which is the main topic of this paper. Next, we outline the various approaches for compression of stereoscopic video and then focus on compatible stereoscopic video coding using MPEG-2 Temporal scalability concepts. Compatible coding employing two different types of prediction structures become potentially possible, disparity compensated prediction and combined disparity and motion compensated predictions. To further improve coding performance and display quality, preprocessing for reducing mismatch between the two views forming stereoscopic video is considered. Results of simulations performed on stereoscopic video of normal TV resolution are then reported comparing the performance of two prediction structures with the simulcast solution. It is found that combined disparity and motion compensated prediction offers the best performance. Results indicate that compression of both views of stereoscopic video of normal TV resolution appears feasible in a total of 6 to 8 Mbit/s. We then discuss regarding multi-viewpoint video, a generalization of stereoscopic video. Finally, we describe ongoing efforts within MPEG-2 to define a profile for stereoscopic video coding, as well as, the promise of MPEG-4 in addressing coding of multi-viewpoint video.

Stereoscopic advantages for vection induced by radial, circular, and spiral optic flows.

PubMed

Palmisano, Stephen; Summersby, Stephanie; Davies, Rodney G; Kim, Juno

2016-11-01

Although observer motions project different patterns of optic flow to our left and right eyes, there has been surprisingly little research into potential stereoscopic contributions to self-motion perception. This study investigated whether visually induced illusory self-motion (i.e., vection) is influenced by the addition of consistent stereoscopic information to radial, circular, and spiral (i.e., combined radial + circular) patterns of optic flow. Stereoscopic vection advantages were found for radial and spiral (but not circular) flows when monocular motion signals were strong. Under these conditions, stereoscopic benefits were greater for spiral flow than for radial flow. These effects can be explained by differences in the motion aftereffects generated by these displays, which suggest that the circular motion component in spiral flow selectively reduced adaptation to stereoscopic motion-in-depth. Stereoscopic vection advantages were not observed for circular flow when monocular motion signals were strong, but emerged when monocular motion signals were weakened. These findings show that stereoscopic information can contribute to visual self-motion perception in multiple ways.

Stereoscopic Analysis of 19 May and 31 Aug 2007 Filament Eruptions

NASA Technical Reports Server (NTRS)

Liewer, Paulett; DeJong, E. M.; Hall, J. R.

2008-01-01

The presentation outline includes results from stereoscopic analysis of SECCHI/EUVI data for 19 May 2007 filament eruption, including the determined 3D trajectory of erupting filament, strong evidence for reconnection below erupting filament as consistent with standard model, and comparison of EUVI and H-alpha images during eruption; and results from stereoscopic analytic of 21 August 2007 filament eruption. Slide topics include standard model of filament eruption; 2007 May 19 STEREO A/SECCHI/EUVI 195 and 304 A: CME signatures and filament eruption, 3D reconstruction of erupting prominence; filament's relation to coronal magnetic fields; 3d reconstructions of filament eruption; height-time plot of eruption from 3D reconstructions; detailed pre-eruptions comparison of H-alpha and EUVI 304 at 12:42 UT; comparisons during the eruption; STEREO prominence and CME August 31, 2007; reconstructions of prominence and leading edges of both dark cavity and CME; and 3D reconstructions of prominence and leading edges.

The compatibility of consumer DLP projectors with time-sequential stereoscopic 3D visualisation

NASA Astrophysics Data System (ADS)

Woods, Andrew J.; Rourke, Tegan

2007-02-01

A range of advertised "Stereo-Ready" DLP projectors are now available in the market which allow high-quality flickerfree stereoscopic 3D visualization using the time-sequential stereoscopic display method. The ability to use a single projector for stereoscopic viewing offers a range of advantages, including extremely good stereoscopic alignment, and in some cases, portability. It has also recently become known that some consumer DLP projectors can be used for timesequential stereoscopic visualization, however it was not well understood which projectors are compatible and incompatible, what display modes (frequency and resolution) are compatible, and what stereoscopic display quality attributes are important. We conducted a study to test a wide range of projectors for stereoscopic compatibility. This paper reports on the testing of 45 consumer DLP projectors of widely different specifications (brand, resolution, brightness, etc). The projectors were tested for stereoscopic compatibility with various video formats (PAL, NTSC, 480P, 576P, and various VGA resolutions) and video input connections (composite, SVideo, component, and VGA). Fifteen projectors were found to work well at up to 85Hz stereo in VGA mode. Twenty three projectors would work at 60Hz stereo in VGA mode.

A dataset of stereoscopic images and ground-truth disparity mimicking human fixations in peripersonal space

PubMed Central

Canessa, Andrea; Gibaldi, Agostino; Chessa, Manuela; Fato, Marco; Solari, Fabio; Sabatini, Silvio P.

2017-01-01

Binocular stereopsis is the ability of a visual system, belonging to a live being or a machine, to interpret the different visual information deriving from two eyes/cameras for depth perception. From this perspective, the ground-truth information about three-dimensional visual space, which is hardly available, is an ideal tool both for evaluating human performance and for benchmarking machine vision algorithms. In the present work, we implemented a rendering methodology in which the camera pose mimics realistic eye pose for a fixating observer, thus including convergent eye geometry and cyclotorsion. The virtual environment we developed relies on highly accurate 3D virtual models, and its full controllability allows us to obtain the stereoscopic pairs together with the ground-truth depth and camera pose information. We thus created a stereoscopic dataset: GENUA PESTO—GENoa hUman Active fixation database: PEripersonal space STereoscopic images and grOund truth disparity. The dataset aims to provide a unified framework useful for a number of problems relevant to human and computer vision, from scene exploration and eye movement studies to 3D scene reconstruction. PMID:28350382

Analysis of physiological impact while reading stereoscopic radiographs

NASA Astrophysics Data System (ADS)

Unno, Yasuko Y.; Tajima, Takashi; Kuwabara, Takao; Hasegawa, Akira; Natsui, Nobutaka; Ishikawa, Kazuo; Hatada, Toyohiko

2011-03-01

A stereoscopic viewing technology is expected to improve diagnostic performance in terms of reading efficiency by adding one more dimension to the conventional 2D images. Although a stereoscopic technology has been applied to many different field including TV, movies and medical applications, physiological fatigue through reading stereoscopic radiographs has been concerned although no established physiological fatigue data have been provided. In this study, we measured the α-amylase concentration in saliva, heart rates and normalized tissue hemoglobin index (nTHI) in blood of frontal area to estimate physiological fatigue through reading both stereoscopic radiographs and the conventional 2D radiographs. In addition, subjective assessments were also performed. As a result, the pupil contraction occurred just after the reading of the stereoscopic images, but the subjective assessments regarding visual fatigue were nearly identical for the reading the conventional 2D and stereoscopic radiographs. The α-amylase concentration and the nTHI continued to decline while examinees read both 2D and stereoscopic images, which reflected the result of subjective assessment that almost half of the examinees reported to feel sleepy after reading. The subjective assessments regarding brain fatigue showed that there were little differences between 2D and stereoscopic reading. In summary, this study shows that the physiological fatigue caused by stereoscopic reading is equivalent to the conventional 2D reading including ocular fatigue and burden imposed on brain.

Efficient stereoscopic contents file format on the basis of ISO base media file format

NASA Astrophysics Data System (ADS)

Kim, Kyuheon; Lee, Jangwon; Suh, Doug Young; Park, Gwang Hoon

2009-02-01

A lot of 3D contents haven been widely used for multimedia services, however, real 3D video contents have been adopted for a limited applications such as a specially designed 3D cinema. This is because of the difficulty of capturing real 3D video contents and the limitation of display devices available in a market. However, diverse types of display devices for stereoscopic video contents for real 3D video contents have been recently released in a market. Especially, a mobile phone with a stereoscopic camera has been released in a market, which provides a user as a consumer to have more realistic experiences without glasses, and also, as a content creator to take stereoscopic images or record the stereoscopic video contents. However, a user can only store and display these acquired stereoscopic contents with his/her own devices due to the non-existence of a common file format for these contents. This limitation causes a user not share his/her contents with any other users, which makes it difficult the relevant market to stereoscopic contents is getting expanded. Therefore, this paper proposes the common file format on the basis of ISO base media file format for stereoscopic contents, which enables users to store and exchange pure stereoscopic contents. This technology is also currently under development for an international standard of MPEG as being called as a stereoscopic video application format.

21 CFR 886.1880 - Fusion and stereoscopic target.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing object...

21 CFR 886.1880 - Fusion and stereoscopic target.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Fusion and stereoscopic target. 886.1880 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1880 Fusion and stereoscopic target. (a) Identification. A fusion and stereoscopic target is a device intended for use as a viewing object...

The rendering context for stereoscopic 3D web

NASA Astrophysics Data System (ADS)

Chen, Qinshui; Wang, Wenmin; Wang, Ronggang

2014-03-01

3D technologies on the Web has been studied for many years, but they are basically monoscopic 3D. With the stereoscopic technology gradually maturing, we are researching to integrate the binocular 3D technology into the Web, creating a stereoscopic 3D browser that will provide users with a brand new experience of human-computer interaction. In this paper, we propose a novel approach to apply stereoscopy technologies to the CSS3 3D Transforms. Under our model, each element can create or participate in a stereoscopic 3D rendering context, in which 3D Transforms such as scaling, translation and rotation, can be applied and be perceived in a truly 3D space. We first discuss the underlying principles of stereoscopy. After that we discuss how these principles can be applied to the Web. A stereoscopic 3D browser with backward compatibility is also created for demonstration purposes. We take advantage of the open-source WebKit project, integrating the 3D display ability into the rendering engine of the web browser. For each 3D web page, our 3D browser will create two slightly different images, each representing the left-eye view and right-eye view, both to be combined on the 3D display to generate the illusion of depth. And as the result turns out, elements can be manipulated in a truly 3D space.

Stereoscopic Imaging in Hypersonics Boundary Layers using Planar Laser-Induced Fluorescence

NASA Technical Reports Server (NTRS)

Danehy, Paul M.; Bathel, Brett; Inman, Jennifer A.; Alderfer, David W.; Jones, Stephen B.

2008-01-01

Stereoscopic time-resolved visualization of three-dimensional structures in a hypersonic flow has been performed for the first time. Nitric Oxide (NO) was seeded into hypersonic boundary layer flows that were designed to transition from laminar to turbulent. A thick laser sheet illuminated and excited the NO, causing spatially-varying fluorescence. Two cameras in a stereoscopic configuration were used to image the fluorescence. The images were processed in a computer visualization environment to provide stereoscopic image pairs. Two methods were used to display these image pairs: a cross-eyed viewing method which can be viewed by naked eyes, and red/blue anaglyphs, which require viewing through red/blue glasses. The images visualized three-dimensional information that would be lost if conventional planar laser-induced fluorescence imaging had been used. Two model configurations were studied in NASA Langley Research Center's 31-Inch Mach 10 Air Wind tunnel. One model was a 10 degree half-angle wedge containing a small protuberance to force the flow to transition. The other model was a 1/3-scale, truncated Hyper-X forebody model with blowing through a series of holes to force the boundary layer flow to transition to turbulence. In the former case, low flowrates of pure NO seeded and marked the boundary layer fluid. In the latter, a trace concentration of NO was seeded into the injected N2 gas. The three-dimensional visualizations have an effective time resolution of about 500 ns, which is fast enough to freeze this hypersonic flow. The 512x512 resolution of the resulting images is much higher than high-speed laser-sheet scanning systems with similar time response, which typically measure 10-20 planes.

[Effects of stereoscopic cultivation on photosynthetic characteristics and growth of Tulipa edulis].

PubMed

Sun, Yuan; Guo, Qiao-Sheng; Zhu, Zai-Biao; Lin, Jian-Luo; Zhou, Bo-Ya; Zhao, Min-Jie

2016-06-01

The effect of stereoscopic cultivation on the growth, photosynthetic characteristics and yield of Tulipa edulis was studied to explore the feasibility of stereoscopic cultivation on efficient cultivation of T.edulis. Total leaf area and photosynthetic parameters of T.edulis under stereoscopic cultivation (the upper, middle and the lower layers ) and the control were measured using LI-3100 leaf area meter and LI-6400XT photosynthesis system in the growing peak period of T.edulis.Plant biomass and biomass allocation were also determined.In addition, the bulb regeneration and yield of T.edulis were measured in the harvesting time.The results indicated that in the middle layer of stereoscopic cultivation, leaf biomass proportion was the highest, but total bulb fresh and dry weight and output growth (fresh weight) were the lowest among the treatments.And total bulb fresh weight in the middle of stereoscopic cultivation reduced significantly, by 22.84%, compared with the control.Light intensity in the lower layer of stereoscopic cultivation was moderate, in which T.edulis net photosynthetic rate and water use efficiency were higher than those of the other layers of stereoscopic cultivation, and bulb biomass proportion was the highest in all the treatments.No significant difference was detected in the total bulb fresh weight, dry weight and output growth (fresh weight) between the middle layer of stereoscopic cultivation and the control.In general, there was no significant difference in the growth status of T.edulis between stereoscopic cultivation and the control.Stereoscopic cultivation increased the yield of T.edulis by 161.66% in fresh weight and 141.35% in dry weight compared with the control in the condition of the same land area, respectively.In conclusion, stereoscopic cultivation can improve space utilization, increase the production, and achieve the high density cultivation of T.edulis. Copyright© by the Chinese Pharmaceutical Association.

Stereoscopic Perception of Women in Real and Virtual Environments: A Study towards Educational Neuroscience

ERIC Educational Resources Information Center

Zacharis, Georgios S.; Mikropoulos, Tassos A.; Priovolou, Chryssi

2013-01-01

Previous studies report the involvement of specific brain activation in stereoscopic vision and the perception of depth information. This work presents the first comparative results of adult women on the effects of stereoscopic perception in three different static environments; a real, a two dimensional (2D) and a stereoscopic three dimensional…

Interactive and Stereoscopic Hybrid 3D Viewer of Radar Data with Gesture Recognition

NASA Astrophysics Data System (ADS)

Goenetxea, Jon; Moreno, Aitor; Unzueta, Luis; Galdós, Andoni; Segura, Álvaro

This work presents an interactive and stereoscopic 3D viewer of weather information coming from a Doppler radar. The hybrid system shows a GIS model of the regional zone where the radar is located and the corresponding reconstructed 3D volume weather data. To enhance the immersiveness of the navigation, stereoscopic visualization has been added to the viewer, using a polarized glasses based system. The user can interact with the 3D virtual world using a Nintendo Wiimote for navigating through it and a Nintendo Wii Nunchuk for giving commands by means of hand gestures. We also present a dynamic gesture recognition procedure that measures the temporal advance of the performed gesture postures. Experimental results show how dynamic gestures are effectively recognized so that a more natural interaction and immersive navigation in the virtual world is achieved.

Human factors involved in perception and action in a natural stereoscopic world: an up-to-date review with guidelines for stereoscopic displays and stereoscopic virtual reality (VR)

NASA Astrophysics Data System (ADS)

Perez-Bayas, Luis

2001-06-01

In stereoscopic perception of a three-dimensional world, binocular disparity might be thought of as the most important cue to 3D depth perception. Nevertheless, in reality there are many other factors involved before the 'final' conscious and subconscious stereoscopic perception, such as luminance, contrast, orientation, color, motion, and figure-ground extraction (pop-out phenomenon). In addition, more complex perceptual factors exist, such as attention and its duration (an equivalent of 'brain zooming') in relation to physiological central vision, In opposition to attention to peripheral vision and the brain 'top-down' information in relation to psychological factors like memory of previous experiences and present emotions. The brain's internal mapping of a pure perceptual world might be different from the internal mapping of a visual-motor space, which represents an 'action-directed perceptual world.' In addition, psychological factors (emotions and fine adjustments) are much more involved in a stereoscopic world than in a flat 2D-world, as well as in a world using peripheral vision (like VR, using a curved perspective representation, and displays, as natural vision does) as opposed to presenting only central vision (bi-macular stereoscopic vision) as in the majority of typical stereoscopic displays. Here is presented the most recent and precise information available about the psycho-neuro- physiological factors involved in the perception of stereoscopic three-dimensional world, with an attempt to give practical, functional, and pertinent guidelines for building more 'natural' stereoscopic displays.

Design of multi-view stereoscopic HD video transmission system based on MPEG-21 digital item adaptation

NASA Astrophysics Data System (ADS)

Lee, Seokhee; Lee, Kiyoung; Kim, Man Bae; Kim, JongWon

2005-11-01

In this paper, we propose a design of multi-view stereoscopic HD video transmission system based on MPEG-21 Digital Item Adaptation (DIA). It focuses on the compatibility and scalability to meet various user preferences and terminal capabilities. There exist a large variety of multi-view 3D HD video types according to the methods for acquisition, display, and processing. By following the MPEG-21 DIA framework, the multi-view stereoscopic HD video is adapted according to user feedback. A user can be served multi-view stereoscopic video which corresponds with his or her preferences and terminal capabilities. In our preliminary prototype, we verify that the proposed design can support two deferent types of display device (stereoscopic and auto-stereoscopic) and switching viewpoints between two available viewpoints.

Learning Receptive Fields and Quality Lookups for Blind Quality Assessment of Stereoscopic Images.

PubMed

Shao, Feng; Lin, Weisi; Wang, Shanshan; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

2016-03-01

Blind quality assessment of 3D images encounters more new challenges than its 2D counterparts. In this paper, we propose a blind quality assessment for stereoscopic images by learning the characteristics of receptive fields (RFs) from perspective of dictionary learning, and constructing quality lookups to replace human opinion scores without performance loss. The important feature of the proposed method is that we do not need a large set of samples of distorted stereoscopic images and the corresponding human opinion scores to learn a regression model. To be more specific, in the training phase, we learn local RFs (LRFs) and global RFs (GRFs) from the reference and distorted stereoscopic images, respectively, and construct their corresponding local quality lookups (LQLs) and global quality lookups (GQLs). In the testing phase, blind quality pooling can be easily achieved by searching optimal GRF and LRF indexes from the learnt LQLs and GQLs, and the quality score is obtained by combining the LRF and GRF indexes together. Experimental results on three publicly 3D image quality assessment databases demonstrate that in comparison with the existing methods, the devised algorithm achieves high consistent alignment with subjective assessment.

Using Saliency-Weighted Disparity Statistics for Objective Visual Comfort Assessment of Stereoscopic Images

NASA Astrophysics Data System (ADS)

Zhang, Wenlan; Luo, Ting; Jiang, Gangyi; Jiang, Qiuping; Ying, Hongwei; Lu, Jing

2016-06-01

Visual comfort assessment (VCA) for stereoscopic images is a particularly significant yet challenging task in 3D quality of experience research field. Although the subjective assessment given by human observers is known as the most reliable way to evaluate the experienced visual discomfort, it is time-consuming and non-systematic. Therefore, it is of great importance to develop objective VCA approaches that can faithfully predict the degree of visual discomfort as human beings do. In this paper, a novel two-stage objective VCA framework is proposed. The main contribution of this study is that the important visual attention mechanism of human visual system is incorporated for visual comfort-aware feature extraction. Specifically, in the first stage, we first construct an adaptive 3D visual saliency detection model to derive saliency map of a stereoscopic image, and then a set of saliency-weighted disparity statistics are computed and combined to form a single feature vector to represent a stereoscopic image in terms of visual comfort. In the second stage, a high dimensional feature vector is fused into a single visual comfort score by performing random forest algorithm. Experimental results on two benchmark databases confirm the superior performance of the proposed approach.

Instruments and Methodologies for the Underwater Tridimensional Digitization and Data Musealization

NASA Astrophysics Data System (ADS)

Repola, L.; Memmolo, R.; Signoretti, D.

2015-04-01

In the research started within the SINAPSIS project of the Università degli Studi Suor Orsola Benincasa an underwater stereoscopic scanning aimed at surveying of submerged archaeological sites, integrable to standard systems for geomorphological detection of the coast, has been developed. The project involves the construction of hardware consisting of an aluminum frame supporting a pair of GoPro Hero Black Edition cameras and software for the production of point clouds and the initial processing of data. The software has features for stereoscopic vision system calibration, reduction of noise and the of distortion of underwater captured images, searching for corresponding points of stereoscopic images using stereo-matching algorithms (dense and sparse), for points cloud generating and filtering. Only after various calibration and survey tests carried out during the excavations envisaged in the project, the mastery of methods for an efficient acquisition of data has been achieved. The current development of the system has allowed generation of portions of digital models of real submerged scenes. A semi-automatic procedure for global registration of partial models is under development as a useful aid for the study and musealization of sites.

An HTML Tool for Production of Interactive Stereoscopic Compositions.

PubMed

Chistyakov, Alexey; Soto, Maria Teresa; Martí, Enric; Carrabina, Jordi

2016-12-01

The benefits of stereoscopic vision in medical applications were appreciated and have been thoroughly studied for more than a century. The usage of the stereoscopic displays has a proven positive impact on performance in various medical tasks. At the same time the market of 3D-enabled technologies is blooming. New high resolution stereo cameras, TVs, projectors, monitors, and head mounted displays become available. This equipment, completed with a corresponding application program interface (API), could be relatively easy implemented in a system. Such complexes could open new possibilities for medical applications exploiting the stereoscopic depth. This work proposes a tool for production of interactive stereoscopic graphical user interfaces, which could represent a software layer for web-based medical systems facilitating the stereoscopic effect. Further the tool's operation mode and the results of the conducted subjective and objective performance tests will be exposed.

Automated volumetric evaluation of stereoscopic disc photography

PubMed Central

Xu, Juan; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Craig, Jamie E; Mackey, David A; Hewitt, Alex W; Schuman, Joel S

2010-01-01

PURPOSE: To develop a fully automated algorithm (AP) to perform a volumetric measure of the optic disc using conventional stereoscopic optic nerve head (ONH) photographs, and to compare algorithm-produced parameters with manual photogrammetry (MP), scanning laser ophthalmoscope (SLO) and optical coherence tomography (OCT) measurements. METHODS: One hundred twenty-two stereoscopic optic disc photographs (61 subjects) were analyzed. Disc area, rim area, cup area, cup/disc area ratio, vertical cup/disc ratio, rim volume and cup volume were automatically computed by the algorithm. Latent variable measurement error models were used to assess measurement reproducibility for the four techniques. RESULTS: AP had better reproducibility for disc area and cup volume and worse reproducibility for cup/disc area ratio and vertical cup/disc ratio, when the measurements were compared to the MP, SLO and OCT methods. CONCLUSION: AP provides a useful technique for an objective quantitative assessment of 3D ONH structures. PMID:20588996

A stereoscopic lens for digital cinema cameras

NASA Astrophysics Data System (ADS)

Lipton, Lenny; Rupkalvis, John

2015-03-01

Live-action stereoscopic feature films are, for the most part, produced using a costly post-production process to convert planar cinematography into stereo-pair images and are only occasionally shot stereoscopically using bulky dual-cameras that are adaptations of the Ramsdell rig. The stereoscopic lens design described here might very well encourage more live-action image capture because it uses standard digital cinema cameras and workflow to save time and money.

A study on correlation between stereographic cinematography and storytelling: through a documentary film about Ho Quyen-UNESCO World heritage in Vietnam

NASA Astrophysics Data System (ADS)

Choi, Yang Hyun; Ahn, Jaehong

2010-02-01

Nowadays stereoscopic technology is being paid attention as a leading technology for the next generation film industry in many countries including Korea. In Korean stereoscopic film production, however, the quality but also the quantity of stereoscopic contents still leaves much to be desired, and know-how and skill of stereoscopic film production has been elevated in tardy progress. This paper shows a research on the correlation between stereoscopic cinematography and storytelling. Based on a casestudy of a documentary film about Ho Quyen, UNESCO World Heritage in Vietnam, we could deliver guidelines for the stereoscopic film production and storytelling. For this study, we analyzed scenes and shots of a documentary film script in pre-production stage. These analysis results were reflected on a storyboard. A stereographer grasped the idea of a storytelling that a director had meant through a script and storyboard. Then he applied suitable parameters for a stereoscopic cinematography to every shot with a beamsplitter rig. A researcher wrote major parameters like interaxial distance, convergence angle in every shot. Then average parameter values of scenes were calculated from the parameter database, and the relationship between stereoscopic cinematography and storytelling was derived by shot-by-shot analysis.

Stereoscopic 3D video games and their effects on engagement

NASA Astrophysics Data System (ADS)

Hogue, Andrew; Kapralos, Bill; Zerebecki, Chris; Tawadrous, Mina; Stanfield, Brodie; Hogue, Urszula

2012-03-01

With television manufacturers developing low-cost stereoscopic 3D displays, a large number of consumers will undoubtedly have access to 3D-capable televisions at home. The availability of 3D technology places the onus on content creators to develop interesting and engaging content. While the technology of stereoscopic displays and content generation are well understood, there are many questions yet to be answered surrounding its effects on the viewer. Effects of stereoscopic display on passive viewers for film are known, however video games are fundamentally different since the viewer/player is actively (rather than passively) engaged in the content. Questions of how stereoscopic viewing affects interaction mechanics have previously been studied in the context of player performance but very few have attempted to quantify the player experience to determine whether stereoscopic 3D has a positive or negative influence on their overall engagement. In this paper we present a preliminary study of the effects stereoscopic 3D have on player engagement in video games. Participants played a video game in two conditions, traditional 2D and stereoscopic 3D and their engagement was quantified using a previously validated self-reporting tool. The results suggest that S3D has a positive effect on immersion, presence, flow, and absorption.

A Review on Stereoscopic 3D: Home Entertainment for the Twenty First Century

NASA Astrophysics Data System (ADS)

Karajeh, Huda; Maqableh, Mahmoud; Masa'deh, Ra'ed

2014-12-01

In the last few years, stereoscopic developed very rapidly and employed in many different fields such as entertainment. Due to the importance of entertainment aspect of stereoscopic 3D (S3D) applications, a review of the current state of S3D development in entertainment technology is conducted. In this paper, a novel survey of the stereoscopic entertainment aspects is presented by discussing the significant development of a 3D cinema, the major development of 3DTV, the issues related to 3D video content and 3D video games. Moreover, we reviewed some problems that can be caused in the viewers' visual system from watching stereoscopic contents. Some stereoscopic viewers are not satisfied as they are frustrated from wearing glasses, have visual fatigue, complain from unavailability of 3D contents, and/or complain from some sickness. Therefore, we will discuss stereoscopic visual discomfort and to what extend the viewer will have an eye fatigue while watching 3D contents or playing 3D games. The suggested solutions in the literature for this problem are discussed.

The ghost of Helioth and his stereoscope: the return of a phantom.

PubMed

Wade, Nicholas J

2012-01-01

Among the myths surrounding the invention of the stereoscope, that of Helioth stands as a supreme example of shoddy scholarship and its subsequent dissemination. Helioth was said to have made a simple stereoscope before Wheatstone presented his mirror stereoscope to the public in 1838. There is no evidence of Helioth's existence prior to a report in the mid-twentieth century, and despite attempts to dispel his ghost it has recently resurfaced.

Tele-transmission of stereoscopic images of the optic nerve head in glaucoma via Internet.

PubMed

Bergua, Antonio; Mardin, Christian Y; Horn, Folkert K

2009-06-01

The objective was to describe an inexpensive system to visualize stereoscopic photographs of the optic nerve head on computer displays and to transmit such images via the Internet for collaborative research or remote clinical diagnosis in glaucoma. Stereoscopic images of glaucoma patients were digitized and stored in a file format (joint photographic stereoimage [jps]) containing all three-dimensional information for both eyes on an Internet Web site (www.trizax.com). The size of jps files was between 0.4 to 1.4 MB (corresponding to a diagonal stereo image size between 900 and 1400 pixels) suitable for Internet protocols. A conventional personal computer system equipped with wireless stereoscopic LCD shutter glasses and a CRT-monitor with high refresh rate (120 Hz) can be used to obtain flicker-free stereo visualization of true-color images with high resolution. Modern thin-film transistor-LCD displays in combination with inexpensive red-cyan goggles achieve stereoscopic visualization with the same resolution but reduced color quality and contrast. The primary aim of our study was met to transmit stereoscopic images via the Internet. Additionally, we found that with both stereoscopic visualization techniques, cup depth, neuroretinal rim shape, and slope of the inner wall of the optic nerve head, can be qualitatively better perceived and interpreted than with monoscopic images. This study demonstrates high-quality and low-cost Internet transmission of stereoscopic images of the optic nerve head from glaucoma patients. The technique allows exchange of stereoscopic images and can be applied to tele-diagnostic and glaucoma research.

Binocular coordination in response to stereoscopic stimuli

NASA Astrophysics Data System (ADS)

Liversedge, Simon P.; Holliman, Nicolas S.; Blythe, Hazel I.

2009-02-01

Humans actively explore their visual environment by moving their eyes. Precise coordination of the eyes during visual scanning underlies the experience of a unified perceptual representation and is important for the perception of depth. We report data from three psychological experiments investigating human binocular coordination during visual processing of stereoscopic stimuli.In the first experiment participants were required to read sentences that contained a stereoscopically presented target word. Half of the word was presented exclusively to one eye and half exclusively to the other eye. Eye movements were recorded and showed that saccadic targeting was uninfluenced by the stereoscopic presentation, strongly suggesting that complementary retinal stimuli are perceived as a single, unified input prior to saccade initiation. In a second eye movement experiment we presented words stereoscopically to measure Panum's Fusional Area for linguistic stimuli. In the final experiment we compared binocular coordination during saccades between simple dot stimuli under 2D, stereoscopic 3D and real 3D viewing conditions. Results showed that depth appropriate vergence movements were made during saccades and fixations to real 3D stimuli, but only during fixations on stereoscopic 3D stimuli. 2D stimuli did not induce depth vergence movements. Together, these experiments indicate that stereoscopic visual stimuli are fused when they fall within Panum's Fusional Area, and that saccade metrics are computed on the basis of a unified percept. Also, there is sensitivity to non-foveal retinal disparity in real 3D stimuli, but not in stereoscopic 3D stimuli, and the system responsible for binocular coordination responds to this during saccades as well as fixations.

An interactive in-game approach to user adjustment of stereoscopic 3D settings

NASA Astrophysics Data System (ADS)

Tawadrous, Mina; Hogue, Andrew; Kapralos, Bill; Collins, Karen

2013-03-01

Given the popularity of 3D film, content developers have been creating customizable stereoscopic 3D experiences for the user to enjoy at home. Stereoscopic 3D game developers often offer a `white box' approach whereby far too many controls and settings are exposed to the average consumer who may have little knowledge or interest to correctly adjust these settings. Improper settings can lead to users being uncomfortable or unimpressed with their own user-defined stereoscopic 3D experience. We have begun investigating interactive approaches to in-game adjustment of the various stereoscopic 3D parameters to reduce the reliance on the user doing so and thefore creating a more pleasurable stereoscopic 3D experience. In this paper, we describe a preliminary technique for interactively calibrating the various stereoscopic 3D parameters and we compare this interface with the typical slider-based control interface game developers utilize in commercial S3D games. Inspired by standard testing methodologies experienced at an optometrist, we've created a split-screen game with the same stereoscopic 3D game running in both screens, but with different interaxial distances. We expect that the interactive nature of the calibration will impact the final game experience providing us with an indication of whether in-game, interactive, S3D parameter calibration is a mechanism that game developers should adopt.

Evaluating methods for controlling depth perception in stereoscopic cinematography

NASA Astrophysics Data System (ADS)

Sun, Geng; Holliman, Nick

2009-02-01

Existing stereoscopic imaging algorithms can create static stereoscopic images with perceived depth control function to ensure a compelling 3D viewing experience without visual discomfort. However, current algorithms do not normally support standard Cinematic Storytelling techniques. These techniques, such as object movement, camera motion, and zooming, can result in dynamic scene depth change within and between a series of frames (shots) in stereoscopic cinematography. In this study, we empirically evaluate the following three types of stereoscopic imaging approaches that aim to address this problem. (1) Real-Eye Configuration: set camera separation equal to the nominal human eye interpupillary distance. The perceived depth on the display is identical to the scene depth without any distortion. (2) Mapping Algorithm: map the scene depth to a predefined range on the display to avoid excessive perceived depth. A new method that dynamically adjusts the depth mapping from scene space to display space is presented in addition to an existing fixed depth mapping method. (3) Depth of Field Simulation: apply Depth of Field (DOF) blur effect to stereoscopic images. Only objects that are inside the DOF are viewed in full sharpness. Objects that are far away from the focus plane are blurred. We performed a human-based trial using the ITU-R BT.500-11 Recommendation to compare the depth quality of stereoscopic video sequences generated by the above-mentioned imaging methods. Our results indicate that viewers' practical 3D viewing volumes are different for individual stereoscopic displays and viewers can cope with much larger perceived depth range in viewing stereoscopic cinematography in comparison to static stereoscopic images. Our new dynamic depth mapping method does have an advantage over the fixed depth mapping method in controlling stereo depth perception. The DOF blur effect does not provide the expected improvement for perceived depth quality control in 3D cinematography. We anticipate the results will be of particular interest to 3D filmmaking and real time computer games.

The right view from the wrong location: depth perception in stereoscopic multi-user virtual environments.

PubMed

Pollock, Brice; Burton, Melissa; Kelly, Jonathan W; Gilbert, Stephen; Winer, Eliot

2012-04-01

Stereoscopic depth cues improve depth perception and increase immersion within virtual environments (VEs). However, improper display of these cues can distort perceived distances and directions. Consider a multi-user VE, where all users view identical stereoscopic images regardless of physical location. In this scenario, cues are typically customized for one "leader" equipped with a head-tracking device. This user stands at the center of projection (CoP) and all other users ("followers") view the scene from other locations and receive improper depth cues. This paper examines perceived depth distortion when viewing stereoscopic VEs from follower perspectives and the impact of these distortions on collaborative spatial judgments. Pairs of participants made collaborative depth judgments of virtual shapes viewed from the CoP or after displacement forward or backward. Forward and backward displacement caused perceived depth compression and expansion, respectively, with greater compression than expansion. Furthermore, distortion was less than predicted by a ray-intersection model of stereo geometry. Collaboration times were significantly longer when participants stood at different locations compared to the same location, and increased with greater perceived depth discrepancy between the two viewing locations. These findings advance our understanding of spatial distortions in multi-user VEs, and suggest a strategy for reducing distortion.

Stereo depth and the control of locomotive heading

NASA Astrophysics Data System (ADS)

Rushton, Simon K.; Harris, Julie M.

1998-04-01

Does the addition of stereoscopic depth aid steering--the perceptual control of locomotor heading--around an environment? This is a critical question when designing a tele-operation or Virtual Environment system, with implications for computational resources and visual comfort. We examined the role of stereoscopic depth in the perceptual control of heading by employing an active steering task. Three conditions were tested: stereoscopic depth; incorrect stereoscopic depth and no stereoscopic depth. Results suggest that stereoscopic depth does not improve performance in a visual control task. A further set of experiments examined the importance of a ground plane. As a ground plane is a common feature of all natural environments and provides a pictorial depth cue, it has been suggested that the visual system may be especially attuned to exploit its presence. Thus it would be predicted that a ground plane would aid judgments of locomotor heading. Results suggest that the presence of rich motion information in the lower visual field produces significant performance advantages and that provision of such information may prove a better target for system resources than stereoscopic depth. These findings have practical consequences for a system designer and also challenge previous theoretical and psychophysical perceptual research.

Brief history of electronic stereoscopic displays

NASA Astrophysics Data System (ADS)

Lipton, Lenny

2012-02-01

A brief history of recent developments in electronic stereoscopic displays is given concentrating on products that have succeeded in the market place and hence have had a significant influence on future implementations. The concentration is on plano-stereoscopic (two-view) technology because it is now the dominant display modality in the marketplace. Stereoscopic displays were created for the motion picture industry a century ago, and this technology influenced the development of products for science and industry, which in turn influenced product development for entertainment.

Stereoscopic augmented reality for laparoscopic surgery.

PubMed

Kang, Xin; Azizian, Mahdi; Wilson, Emmanuel; Wu, Kyle; Martin, Aaron D; Kane, Timothy D; Peters, Craig A; Cleary, Kevin; Shekhar, Raj

2014-07-01

Conventional laparoscopes provide a flat representation of the three-dimensional (3D) operating field and are incapable of visualizing internal structures located beneath visible organ surfaces. Computed tomography (CT) and magnetic resonance (MR) images are difficult to fuse in real time with laparoscopic views due to the deformable nature of soft-tissue organs. Utilizing emerging camera technology, we have developed a real-time stereoscopic augmented-reality (AR) system for laparoscopic surgery by merging live laparoscopic ultrasound (LUS) with stereoscopic video. The system creates two new visual cues: (1) perception of true depth with improved understanding of 3D spatial relationships among anatomical structures, and (2) visualization of critical internal structures along with a more comprehensive visualization of the operating field. The stereoscopic AR system has been designed for near-term clinical translation with seamless integration into the existing surgical workflow. It is composed of a stereoscopic vision system, a LUS system, and an optical tracker. Specialized software processes streams of imaging data from the tracked devices and registers those in real time. The resulting two ultrasound-augmented video streams (one for the left and one for the right eye) give a live stereoscopic AR view of the operating field. The team conducted a series of stereoscopic AR interrogations of the liver, gallbladder, biliary tree, and kidneys in two swine. The preclinical studies demonstrated the feasibility of the stereoscopic AR system during in vivo procedures. Major internal structures could be easily identified. The system exhibited unobservable latency with acceptable image-to-video registration accuracy. We presented the first in vivo use of a complete system with stereoscopic AR visualization capability. This new capability introduces new visual cues and enhances visualization of the surgical anatomy. The system shows promise to improve the precision and expand the capacity of minimally invasive laparoscopic surgeries.

Analysis of Performance of Stereoscopic-Vision Software

NASA Technical Reports Server (NTRS)

Kim, Won; Ansar, Adnan; Steele, Robert; Steinke, Robert

2007-01-01

A team of JPL researchers has analyzed stereoscopic vision software and produced a document describing its performance. This software is of the type used in maneuvering exploratory robotic vehicles on Martian terrain. The software in question utilizes correlations between portions of the images recorded by two electronic cameras to compute stereoscopic disparities, which, in conjunction with camera models, are used in computing distances to terrain points to be included in constructing a three-dimensional model of the terrain. The analysis included effects of correlation- window size, a pyramidal image down-sampling scheme, vertical misalignment, focus, maximum disparity, stereo baseline, and range ripples. Contributions of sub-pixel interpolation, vertical misalignment, and foreshortening to stereo correlation error were examined theoretically and experimentally. It was found that camera-calibration inaccuracy contributes to both down-range and cross-range error but stereo correlation error affects only the down-range error. Experimental data for quantifying the stereo disparity error were obtained by use of reflective metrological targets taped to corners of bricks placed at known positions relative to the cameras. For the particular 1,024-by-768-pixel cameras of the system analyzed, the standard deviation of the down-range disparity error was found to be 0.32 pixel.

A foreground object features-based stereoscopic image visual comfort assessment model

NASA Astrophysics Data System (ADS)

Jin, Xin; Jiang, G.; Ying, H.; Yu, M.; Ding, S.; Peng, Z.; Shao, F.

2014-11-01

Since stereoscopic images provide observers with both realistic and discomfort viewing experience, it is necessary to investigate the determinants of visual discomfort. By considering that foreground object draws most attention when human observing stereoscopic images. This paper proposes a new foreground object based visual comfort assessment (VCA) metric. In the first place, a suitable segmentation method is applied to disparity map and then the foreground object is ascertained as the one having the biggest average disparity. In the second place, three visual features being average disparity, average width and spatial complexity of foreground object are computed from the perspective of visual attention. Nevertheless, object's width and complexity do not consistently influence the perception of visual comfort in comparison with disparity. In accordance with this psychological phenomenon, we divide the whole images into four categories on the basis of different disparity and width, and exert four different models to more precisely predict its visual comfort in the third place. Experimental results show that the proposed VCA metric outperformance other existing metrics and can achieve a high consistency between objective and subjective visual comfort scores. The Pearson Linear Correlation Coefficient (PLCC) and Spearman Rank Order Correlation Coefficient (SROCC) are over 0.84 and 0.82, respectively.

If you watch it move, you'll recognize it in 3D: Transfer of depth cues between encoding and retrieval.

PubMed

Papenmeier, Frank; Schwan, Stephan

2016-02-01

Viewing objects with stereoscopic displays provides additional depth cues through binocular disparity supporting object recognition. So far, it was unknown whether this results from the representation of specific stereoscopic information in memory or a more general representation of an object's depth structure. Therefore, we investigated whether continuous object rotation acting as depth cue during encoding results in a memory representation that can subsequently be accessed by stereoscopic information during retrieval. In Experiment 1, we found such transfer effects from continuous object rotation during encoding to stereoscopic presentations during retrieval. In Experiments 2a and 2b, we found that the continuity of object rotation is important because only continuous rotation and/or stereoscopic depth but not multiple static snapshots presented without stereoscopic information caused the extraction of an object's depth structure into memory. We conclude that an object's depth structure and not specific depth cues are represented in memory. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effect of Two-dimensional and Stereoscopic Presentation on Middle School Students' Performance of Spatial Cognition Tasks

NASA Astrophysics Data System (ADS)

Price, Aaron; Lee, Hee-Sun

2010-02-01

We investigated whether and how student performance on three types of spatial cognition tasks differs when worked with two-dimensional or stereoscopic representations. We recruited nineteen middle school students visiting a planetarium in a large Midwestern American city and analyzed their performance on a series of spatial cognition tasks in terms of response accuracy and task completion time. Results show that response accuracy did not differ between the two types of representations while task completion time was significantly greater with the stereoscopic representations. The completion time increased as the number of mental manipulations of 3D objects increased in the tasks. Post-interviews provide evidence that some students continued to think of stereoscopic representations as two-dimensional. Based on cognitive load and cue theories, we interpret that, in the absence of pictorial depth cues, students may need more time to be familiar with stereoscopic representations for optimal performance. In light of these results, we discuss potential uses of stereoscopic representations for science learning.

Two Eyes, 3D: Stereoscopic Design Principles

NASA Astrophysics Data System (ADS)

Price, Aaron; Subbarao, M.; Wyatt, R.

2013-01-01

Two Eyes, 3D is a NSF-funded research project about how people perceive highly spatial objects when shown with 2D or stereoscopic ("3D") representations. As part of the project, we produced a short film about SN 2011fe. The high definition film has been rendered in both 2D and stereoscopic formats. It was developed according to a set of stereoscopic design principles we derived from the literature and past experience producing and studying stereoscopic films. Study participants take a pre- and post-test that involves a spatial cognition assessment and scientific knowledge questions about Type-1a supernovae. For the evaluation, participants use iPads in order to record spatial manipulation of the device and look for elements of embodied cognition. We will present early results and also describe the stereoscopic design principles and the rationale behind them. All of our content and software is available under open source licenses. More information is at www.twoeyes3d.org.

Clinically Normal Stereopsis Does Not Ensure Performance Benefit from Stereoscopic 3D Depth Cues

DTIC Science & Technology

2014-10-28

Stereopsis, Binocular Vision, Optometry , Depth Perception, 3D vision, 3D human factors, Stereoscopic displays, S3D, Virtual environment 16...Binocular Vision, Optometry , Depth Perception, 3D vision, 3D human factors, Stereoscopic displays, S3D, Virtual environment 1 Distribution A: Approved

Designing stereoscopic information visualization for 3D-TV: What can we can learn from S3D gaming?

NASA Astrophysics Data System (ADS)

Schild, Jonas; Masuch, Maic

2012-03-01

This paper explores graphical design and spatial alignment of visual information and graphical elements into stereoscopically filmed content, e.g. captions, subtitles, and especially more complex elements in 3D-TV productions. The method used is a descriptive analysis of existing computer- and video games that have been adapted for stereoscopic display using semi-automatic rendering techniques (e.g. Nvidia 3D Vision) or games which have been specifically designed for stereoscopic vision. Digital games often feature compelling visual interfaces that combine high usability with creative visual design. We explore selected examples of game interfaces in stereoscopic vision regarding their stereoscopic characteristics, how they draw attention, how we judge effect and comfort and where the interfaces fail. As a result, we propose a list of five aspects which should be considered when designing stereoscopic visual information: explicit information, implicit information, spatial reference, drawing attention, and vertical alignment. We discuss possible consequences, opportunities and challenges for integrating visual information elements into 3D-TV content. This work shall further help to improve current editing systems and identifies a need for future editing systems for 3DTV, e.g., live editing and real-time alignment of visual information into 3D footage.

S3D depth-axis interaction for video games: performance and engagement

NASA Astrophysics Data System (ADS)

Zerebecki, Chris; Stanfield, Brodie; Hogue, Andrew; Kapralos, Bill; Collins, Karen

2013-03-01

Game developers have yet to embrace and explore the interactive stereoscopic 3D medium. They typically view stereoscopy as a separate mode that can be disabled throughout the design process and rarely develop game mechanics that take advantage of the stereoscopic 3D medium. What if we designed games to be S3D-specific and viewed traditional 2D viewing as a separate mode that can be disabled? The design choices made throughout such a process may yield interesting and compelling results. Furthermore, we believe that interaction within a stereoscopic 3D environment is more important than the visual experience itself and therefore, further exploration is needed to take into account the interactive affordances presented by stereoscopic 3D displays. Stereoscopic 3D displays allow players to perceive objects at different depths, thus we hypothesize that designing a core mechanic to take advantage of this viewing paradigm will create compelling content. In this paper, we describe Z-Fighter a game that we have developed that requires the player to interact directly along the stereoscopic 3D depth axis. We also outline an experiment conducted to investigate the performance, perception, and enjoyment of this game in stereoscopic 3D vs. traditional 2D viewing.

Original and creative stereoscopic film making

NASA Astrophysics Data System (ADS)

Criado, Enrique

2008-02-01

The stereoscopic cinema has become, once again, a hot topic in the film production. For filmmakers to be successful in this field, a technical background in the principles of binocular perception and how our brain interprets the incoming data from our eyes, are fundamental. It is also paramount for a stereoscopic production to adhere certain rules for comfort and safety. There is an immense variety of options in the art of standard "flat" photography, and the possibilities only can be multiply with the stereo. The stereoscopic imaging has its own unique areas for subjective, original and creative control that allow an incredible range of possible combinations by working inside the standards, and in some cases on the boundaries of the basic stereo rules. The stereoscopic imaging can be approached in a "flat" manner, like channeling sound through an audio equalizer with all the bands at the same level. It can provide a realistic perception, which in many cases can be sufficient, thanks to the rock-solid viewing inherent to the stereoscopic image, but there are many more possibilities. This document describes some of the basic operating parameters and concepts for stereoscopic imaging, but it also offers ideas for a creative process based on the variation and combination of these basic parameters, which can lead into a truly innovative and original viewing experience.

Depth Perception and the History of Three-Dimensional Art: Who Produced the First Stereoscopic Images?

PubMed Central

2017-01-01

The history of the expression of three-dimensional structure in art can be traced from the use of occlusion in Palaeolithic cave paintings, through the use of shadow in classical art, to the development of perspective during the Renaissance. However, the history of the use of stereoscopic techniques is controversial. Although the first undisputed stereoscopic images were presented by Wheatstone in 1838, it has been claimed that two sketches by Jacopo Chimenti da Empoli (c. 1600) can be to be fused to yield an impression of stereoscopic depth, while others suggest that Leonardo da Vinci’s Mona Lisa is the world’s first stereogram. Here, we report the first quantitative study of perceived depth in these works, in addition to more recent works by Salvador Dalí. To control for the contribution of monocular depth cues, ratings of the magnitude and coherence of depth were recorded for both stereoscopic and pseudoscopic presentations, with a genuine contribution of stereoscopic cues revealed by a difference between these scores. Although effects were clear for Wheatstone and Dalí’s images, no such effects could be found for works produced earlier. As such, we have no evidence to reject the conventional view that the first producer of stereoscopic imagery was Sir Charles Wheatstone. PMID:28203349

Depth Perception and the History of Three-Dimensional Art: Who Produced the First Stereoscopic Images?

PubMed

Brooks, Kevin R

2017-01-01

The history of the expression of three-dimensional structure in art can be traced from the use of occlusion in Palaeolithic cave paintings, through the use of shadow in classical art, to the development of perspective during the Renaissance. However, the history of the use of stereoscopic techniques is controversial. Although the first undisputed stereoscopic images were presented by Wheatstone in 1838, it has been claimed that two sketches by Jacopo Chimenti da Empoli (c. 1600) can be to be fused to yield an impression of stereoscopic depth, while others suggest that Leonardo da Vinci's Mona Lisa is the world's first stereogram. Here, we report the first quantitative study of perceived depth in these works, in addition to more recent works by Salvador Dalí. To control for the contribution of monocular depth cues, ratings of the magnitude and coherence of depth were recorded for both stereoscopic and pseudoscopic presentations, with a genuine contribution of stereoscopic cues revealed by a difference between these scores. Although effects were clear for Wheatstone and Dalí's images, no such effects could be found for works produced earlier. As such, we have no evidence to reject the conventional view that the first producer of stereoscopic imagery was Sir Charles Wheatstone.

Interactive floating windows: a new technique for stereoscopic video games

NASA Astrophysics Data System (ADS)

Zerebecki, Chris; Stanfield, Brodie; Tawadrous, Mina; Buckstein, Daniel; Hogue, Andrew; Kapralos, Bill

2012-03-01

The film industry has a long history of creating compelling experiences in stereoscopic 3D. Recently, the video game as an artistic medium has matured into an effective way to tell engaging and immersive stories. Given the current push to bring stereoscopic 3D technology into the consumer market there is considerable interest to develop stereoscopic 3D video games. Game developers have largely ignored the need to design their games specifically for stereoscopic 3D and have thus relied on automatic conversion and driver technology. Game developers need to evaluate solutions used in other media, such as film, to correct perceptual problems such as window violations, and modify or create new solutions to work within an interactive framework. In this paper we extend the dynamic floating window technique into the interactive domain enabling the player to position a virtual window in space. Interactively changing the position, size, and the 3D rotation of the virtual window, objects can be made to 'break the mask' dramatically enhancing the stereoscopic effect. By demonstrating that solutions from the film industry can be extended into the interactive space, it is our hope that this initiates further discussion in the game development community to strengthen their story-telling mechanisms in stereoscopic 3D games.

Redundancy of stereoscopic images: Experimental evaluation

NASA Astrophysics Data System (ADS)

Yaroslavsky, L. P.; Campos, J.; Espínola, M.; Ideses, I.

2005-12-01

With the recent advancement in visualization devices over the last years, we are seeing a growing market for stereoscopic content. In order to convey 3D content by means of stereoscopic displays, one needs to transmit and display at least 2 points of view of the video content. This has profound implications on the resources required to transmit the content, as well as demands on the complexity of the visualization system. It is known that stereoscopic images are redundant which may prove useful for compression and may have positive effect on the construction of the visualization device. In this paper we describe an experimental evaluation of data redundancy in color stereoscopic images. In the experiments with computer generated and real life test stereo images, several observers visually tested the stereopsis threshold and accuracy of parallax measurement in anaglyphs and stereograms as functions of the blur degree of one of two stereo images. In addition, we tested the color saturation threshold in one of two stereo images for which full color 3D perception with no visible color degradations was maintained. The experiments support a theoretical estimate that one has to add, to data required to reproduce one of two stereoscopic images, only several percents of that amount of data in order to achieve stereoscopic perception.

Stereoscopic Integrated Imaging Goggles for Multimodal Intraoperative Image Guidance

PubMed Central

Mela, Christopher A.; Patterson, Carrie; Thompson, William K.; Papay, Francis; Liu, Yang

2015-01-01

We have developed novel stereoscopic wearable multimodal intraoperative imaging and display systems entitled Integrated Imaging Goggles for guiding surgeries. The prototype systems offer real time stereoscopic fluorescence imaging and color reflectance imaging capacity, along with in vivo handheld microscopy and ultrasound imaging. With the Integrated Imaging Goggle, both wide-field fluorescence imaging and in vivo microscopy are provided. The real time ultrasound images can also be presented in the goggle display. Furthermore, real time goggle-to-goggle stereoscopic video sharing is demonstrated, which can greatly facilitate telemedicine. In this paper, the prototype systems are described, characterized and tested in surgeries in biological tissues ex vivo. We have found that the system can detect fluorescent targets with as low as 60 nM indocyanine green and can resolve structures down to 0.25 mm with large FOV stereoscopic imaging. The system has successfully guided simulated cancer surgeries in chicken. The Integrated Imaging Goggle is novel in 4 aspects: it is (a) the first wearable stereoscopic wide-field intraoperative fluorescence imaging and display system, (b) the first wearable system offering both large FOV and microscopic imaging simultaneously, (c) the first wearable system that offers both ultrasound imaging and fluorescence imaging capacities, and (d) the first demonstration of goggle-to-goggle communication to share stereoscopic views for medical guidance. PMID:26529249

Interlopers 3D: experiences designing a stereoscopic game

NASA Astrophysics Data System (ADS)

Weaver, James; Holliman, Nicolas S.

2014-03-01

Background In recent years 3D-enabled televisions, VR headsets and computer displays have become more readily available in the home. This presents an opportunity for game designers to explore new stereoscopic game mechanics and techniques that have previously been unavailable in monocular gaming. Aims To investigate the visual cues that are present in binocular and monocular vision, identifying which are relevant when gaming using a stereoscopic display. To implement a game whose mechanics are so reliant on binocular cues that the game becomes impossible or at least very difficult to play in non-stereoscopic mode. Method A stereoscopic 3D game was developed whose objective was to shoot down advancing enemies (the Interlopers) before they reached their destination. Scoring highly required players to make accurate depth judgments and target the closest enemies first. A group of twenty participants played both a basic and advanced version of the game in both monoscopic 2D and stereoscopic 3D. Results The results show that in both the basic and advanced game participants achieved higher scores when playing in stereoscopic 3D. The advanced game showed that by disrupting the depth from motion cue the game became more difficult in monoscopic 2D. Results also show a certain amount of learning taking place over the course of the experiment, meaning that players were able to score higher and finish the game faster over the course of the experiment. Conclusions Although the game was not impossible to play in monoscopic 2D, participants results show that it put them at a significant disadvantage when compared to playing in stereoscopic 3D.

Using mental rotation to evaluate the benefits of stereoscopic displays

NASA Astrophysics Data System (ADS)

Aitsiselmi, Y.; Holliman, N. S.

2009-02-01

Context: The idea behind stereoscopic displays is to create the illusion of depth and this concept could have many practical applications. A common spatial ability test involves mental rotation. Therefore a mental rotation task should be easier if being undertaken on a stereoscopic screen. Aim: The aim of this project is to evaluate stereoscopic displays (3D screen) and to assess whether they are better for performing a certain task than over a 2D display. A secondary aim was to perform a similar study but replicating the conditions of using a stereoscopic mobile phone screen. Method: We devised a spatial ability test involving a mental rotation task that participants were asked to complete on either a 3D or 2D screen. We also design a similar task to simulate the experience on a stereoscopic cell phone. The participants' error rate and response times were recorded. Using statistical analysis, we then compared the error rate and response times of the groups to see if there were any significant differences. Results: We found that the participants got better scores if they were doing the task on a stereoscopic screen as opposed to a 2D screen. However there was no statistically significant difference in the time it took them to complete the task. We also found similar results for 3D cell phone display condition. Conclusions: The results show that the extra depth information given by a stereoscopic display makes it easier to mentally rotate a shape as depth cues are readily available. These results could have many useful implications to certain industries.

Visualization of stereoscopic anatomic models of the paranasal sinuses and cervical vertebrae from the surgical and procedural perspective.

PubMed

Chen, Jian; Smith, Andrew D; Khan, Majid A; Sinning, Allan R; Conway, Marianne L; Cui, Dongmei

2017-11-01

Recent improvements in three-dimensional (3D) virtual modeling software allows anatomists to generate high-resolution, visually appealing, colored, anatomical 3D models from computed tomography (CT) images. In this study, high-resolution CT images of a cadaver were used to develop clinically relevant anatomic models including facial skull, nasal cavity, septum, turbinates, paranasal sinuses, optic nerve, pituitary gland, carotid artery, cervical vertebrae, atlanto-axial joint, cervical spinal cord, cervical nerve root, and vertebral artery that can be used to teach clinical trainees (students, residents, and fellows) approaches for trans-sphenoidal pituitary surgery and cervical spine injection procedure. Volume, surface rendering and a new rendering technique, semi-auto-combined, were applied in the study. These models enable visualization, manipulation, and interaction on a computer and can be presented in a stereoscopic 3D virtual environment, which makes users feel as if they are inside the model. Anat Sci Educ 10: 598-606. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Distance Perception of Stereoscopically Presented Virtual Objects Optically Superimposed on Physical Objects by a Head-Mounted See-Through Display

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Bucher, Urs J.; Statler, Irving C. (Technical Monitor)

1994-01-01

The influence of physically presented background stimuli on the perceived depth of optically overlaid, stereoscopic virtual images has been studied using headmounted stereoscopic, virtual image displays. These displays allow presentation of physically unrealizable stimulus combinations. Positioning of an opaque physical object either at the initial perceived depth of the virtual image or at a position substantially in front of the virtual image, causes the virtual image to perceptually move closer to the observer. In the case of objects positioned substantially in front of the virtual image, subjects often perceive the opaque object to become transparent. Evidence is presented that the apparent change of position caused by interposition of the physical object is not due to occlusion cues. According, it may have an alternative cause such as variation in the binocular vengeance position of the eyes caused by introduction of the physical object. This effect may complicate design of overlaid virtual image displays for near objects and appears to be related to the relative conspicuousness of the overlaid virtual image and the background. Consequently, it may be related to earlier analyses of John Foley which modeled open-loop pointing errors to stereoscopically presented points of light in terms of errors in determination of a reference point for interpretation of observed retinal disparities. Implications for the design of see-through displays for manufacturing will be discussed.

Use of the stereoscopic virtual reality display system for the detection and characterization of intracranial aneurysms: A Icomparison with conventional computed tomography workstation and 3D rotational angiography.

PubMed

Liu, Xiujuan; Tao, Haiquan; Xiao, Xigang; Guo, Binbin; Xu, Shangcai; Sun, Na; Li, Maotong; Xie, Li; Wu, Changjun

2018-07-01

This study aimed to compare the diagnostic performance of the stereoscopic virtual reality display system with the conventional computed tomography (CT) workstation and three-dimensional rotational angiography (3DRA) for intracranial aneurysm detection and characterization, with a focus on small aneurysms and those near the bone. First, 42 patients with suspected intracranial aneurysms underwent both 256-row CT angiography (CTA) and 3DRA. Volume rendering (VR) images were captured using the conventional CT workstation. Next, VR images were transferred to the stereoscopic virtual reality display system. Two radiologists independently assessed the results that were obtained using the conventional CT workstation and stereoscopic virtual reality display system. The 3DRA results were considered as the ultimate reference standard. Based on 3DRA images, 38 aneurysms were confirmed in 42 patients. Two cases were misdiagnosed and 1 was missed when the traditional CT workstation was used. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional CT workstation were 94.7%, 85.7%, 97.3%, 75%, and99.3%, respectively, on a per-aneurysm basis. The stereoscopic virtual reality display system missed a case. The sensitivity, specificity, PPV, NPV, and accuracy of the stereoscopic virtual reality display system were 100%, 85.7%, 97.4%, 100%, and 97.8%, respectively. No difference was observed in the accuracy of the traditional CT workstation, stereoscopic virtual reality display system, and 3DRA in detecting aneurysms. The stereoscopic virtual reality display system has some advantages in detecting small aneurysms and those near the bone. The virtual reality stereoscopic vision obtained through the system was found as a useful tool in intracranial aneurysm diagnosis and pre-operative 3D imaging. Copyright © 2018 Elsevier B.V. All rights reserved.

Depth Perception In Remote Stereoscopic Viewing Systems

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Von Sydow, Marika

1989-01-01

Report describes theoretical and experimental studies of perception of depth by human operators through stereoscopic video systems. Purpose of such studies to optimize dual-camera configurations used to view workspaces of remote manipulators at distances of 1 to 3 m from cameras. According to analysis, static stereoscopic depth distortion decreased, without decreasing stereoscopitc depth resolution, by increasing camera-to-object and intercamera distances and camera focal length. Further predicts dynamic stereoscopic depth distortion reduced by rotating cameras around center of circle passing through point of convergence of viewing axes and first nodal points of two camera lenses.

Polarizing aperture stereoscopic cinema camera

NASA Astrophysics Data System (ADS)

Lipton, Lenny

2012-03-01

The art of stereoscopic cinematography has been held back because of the lack of a convenient way to reduce the stereo camera lenses' interaxial to less than the distance between the eyes. This article describes a unified stereoscopic camera and lens design that allows for varying the interaxial separation to small values using a unique electro-optical polarizing aperture design for imaging left and right perspective views onto a large single digital sensor (the size of the standard 35mm frame) with the means to select left and right image information. Even with the added stereoscopic capability the appearance of existing camera bodies will be unaltered.

Polarizing aperture stereoscopic cinema camera

NASA Astrophysics Data System (ADS)

Lipton, Lenny

2012-07-01

The art of stereoscopic cinematography has been held back because of the lack of a convenient way to reduce the stereo camera lenses' interaxial to less than the distance between the eyes. This article describes a unified stereoscopic camera and lens design that allows for varying the interaxial separation to small values using a unique electro-optical polarizing aperture design for imaging left and right perspective views onto a large single digital sensor, the size of the standard 35 mm frame, with the means to select left and right image information. Even with the added stereoscopic capability, the appearance of existing camera bodies will be unaltered.

Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.

PubMed

Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L

2015-06-01

Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.

[Dendrobium officinale stereoscopic cultivation method].

PubMed

Si, Jin-Ping; Dong, Hong-Xiu; Liao, Xin-Yan; Zhu, Yu-Qiu; Li, Hui

2014-12-01

The study is aimed to make the most of available space of Dendrobium officinale cultivation facility, reveal the yield and functional components variation of stereoscopic cultivated D. officinale, and improve quality, yield and efficiency. The agronomic traits and yield variation of stereoscopic cultivated D. officinale were studied by operating field experiment. The content of polysaccharide and extractum were determined by using phenol-sulfuric acid method and 2010 edition of "Chinese Pharmacopoeia" Appendix X A. The results showed that the land utilization of stereoscopic cultivated D. officinale increased 2.74 times, the stems, leaves and their total fresh or dry weight in unit area of stereoscopic cultivated D. officinale were all heavier than those of the ground cultivated ones. There was no significant difference in polysaccharide content between stereoscopic cultivation and ground cultivation. But the extractum content and total content of polysaccharide and extractum were significantly higher than those of the ground cultivated ones. In additional, the polysaccharide content and total content of polysaccharide and extractum from the top two levels of stereoscopic culture matrix were significantly higher than that of the ones from the other levels and ground cultivation. Steroscopic cultivation can effectively improves the utilization of space and yield, while the total content of polysaccharides and extractum were significantly higher than that of the ground cultivated ones. The significant difference in Dendrobium polysaccharides among the plants from different height of stereo- scopic culture matrix may be associated with light factor.

Saliency Detection for Stereoscopic 3D Images in the Quaternion Frequency Domain

NASA Astrophysics Data System (ADS)

Cai, Xingyu; Zhou, Wujie; Cen, Gang; Qiu, Weiwei

2018-06-01

Recent studies have shown that a remarkable distinction exists between human binocular and monocular viewing behaviors. Compared with two-dimensional (2D) saliency detection models, stereoscopic three-dimensional (S3D) image saliency detection is a more challenging task. In this paper, we propose a saliency detection model for S3D images. The final saliency map of this model is constructed from the local quaternion Fourier transform (QFT) sparse feature and global QFT log-Gabor feature. More specifically, the local QFT feature measures the saliency map of an S3D image by analyzing the location of a similar patch. The similar patch is chosen using a sparse representation method. The global saliency map is generated by applying the wake edge-enhanced gradient QFT map through a band-pass filter. The results of experiments on two public datasets show that the proposed model outperforms existing computational saliency models for estimating S3D image saliency.

How much camera separation should be used for the capture and presentation of 3D stereoscopic imagery on binocular HMDs?

NASA Astrophysics Data System (ADS)

McIntire, John; Geiselman, Eric; Heft, Eric; Havig, Paul

2011-06-01

Designers, researchers, and users of binocular stereoscopic head- or helmet-mounted displays (HMDs) face the tricky issue of what imagery to present in their particular displays, and how to do so effectively. Stereoscopic imagery must often be created in-house with a 3D graphics program or from within a 3D virtual environment, or stereoscopic photos/videos must be carefully captured, perhaps for relaying to an operator in a teleoperative system. In such situations, the question arises as to what camera separation (real or virtual) is appropriate or desirable for end-users and operators. We review some of the relevant literature regarding the question of stereo pair camera separation using deskmounted or larger scale stereoscopic displays, and employ our findings to potential HMD applications, including command & control, teleoperation, information and scientific visualization, and entertainment.

Stereoscopic depth increases intersubject correlations of brain networks.

PubMed

Gaebler, Michael; Biessmann, Felix; Lamke, Jan-Peter; Müller, Klaus-Robert; Walter, Henrik; Hetzer, Stefan

2014-10-15

Three-dimensional movies presented via stereoscopic displays have become more popular in recent years aiming at a more engaging viewing experience. However, neurocognitive processes associated with the perception of stereoscopic depth in complex and dynamic visual stimuli remain understudied. Here, we investigate the influence of stereoscopic depth on both neurophysiology and subjective experience. Using multivariate statistical learning methods, we compare the brain activity of subjects when freely watching the same movies in 2D and in 3D. Subjective reports indicate that 3D movies are more strongly experienced than 2D movies. On the neural level, we observe significantly higher intersubject correlations of cortical networks when subjects are watching 3D movies relative to the same movies in 2D. We demonstrate that increases in intersubject correlations of brain networks can serve as neurophysiological marker for stereoscopic depth and for the strength of the viewing experience. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Doing Textiles Experiments in Game-Based Virtual Reality: A Design of the Stereoscopic Chemical Laboratory (SCL) for Textiles Education

ERIC Educational Resources Information Center

Lau, Kung Wong; Kan, Chi Wai; Lee, Pui Yuen

2017-01-01

Purpose: The purpose of this paper is to discuss the use of stereoscopic virtual technology in textile and fashion studies in particular to the area of chemical experiment. The development of a designed virtual platform, called Stereoscopic Chemical Laboratory (SCL), is introduced. Design/methodology/approach: To implement the suggested…

Evaluating stereoscopic displays: both efficiency measures and perceived workload sensitive to manipulations in binocular disparity

NASA Astrophysics Data System (ADS)

van Beurden, Maurice H. P. H.; Ijsselsteijn, Wijnand A.; de Kort, Yvonne A. W.

2011-03-01

Stereoscopic displays are known to offer a number of key advantages in visualizing complex 3D structures or datasets. The large majority of studies that focus on evaluating stereoscopic displays for professional applications use completion time and/or the percentage of correct answers to measure potential performance advantages. However, completion time and accuracy may not fully reflect all the benefits of stereoscopic displays. In this paper, we argue that perceived workload is an additional valuable indicator reflecting the extent to which users can benefit from using stereoscopic displays. We performed an experiment in which participants were asked to perform a visual path-tracing task within a convoluted 3D wireframe structure, varying in level of complexity of the visualised structure and level of disparity of the visualisation. The results showed that an optimal performance (completion time, accuracy and workload), depend both on task difficulty and disparity level. Stereoscopic disparity revealed a faster and more accurate task performance, whereas we observed a trend that performance on difficult tasks stands to benefit more from higher levels of disparity than performance on easy tasks. Perceived workload (as measured using the NASA-TLX) showed a similar response pattern, providing evidence that perceived workload is sensitive to variations in disparity as well as task difficulty. This suggests that perceived workload could be a useful concept, in addition to standard performance indicators, in characterising and measuring human performance advantages when using stereoscopic displays.

Effects of Seating Location and Stereoscopic Display on Learning Outcomes in an Introductory Physical Geography Class

ERIC Educational Resources Information Center

Hirmas, Daniel R.; Slocum, Terry; Halfen, Alan F.; White, Travis; Zautner, Eric; Atchley, Paul; Liu, Huan; Johnson, William C.; Egbert, Stephen; McDermott, Dave

2014-01-01

Recently, the use of stereoscopic three-dimensional (3-D) projection displays has increased in geoscience education. One concern in employing 3-D projection systems in large lecture halls, however, is that the 3-D effect is reported to diminish with increased angle and distance from the stereoscopic display. The goal of this work was to study that…

Stereoscopic Configurations To Minimize Distortions

NASA Technical Reports Server (NTRS)

Diner, Daniel B.

1991-01-01

Proposed television system provides two stereoscopic displays. Two-camera, two-monitor system used in various camera configurations and with stereoscopic images on monitors magnified to various degrees. Designed to satisfy observer's need to perceive spatial relationships accurately throughout workspace or to perceive them at high resolution in small region of workspace. Potential applications include industrial, medical, and entertainment imaging and monitoring and control of telemanipulators, telerobots, and remotely piloted vehicles.

Psychometric Assessment of Stereoscopic Head-Mounted Displays

DTIC Science & Technology

2016-06-29

Journal Article 3. DATES COVERED (From – To) Jan 2015 - Dec 2015 4. TITLE AND SUBTITLE PSYCHOMETRIC ASSESSMENT OF STEREOSCOPIC HEAD- MOUNTED DISPLAYS...to render an immersive three-dimensional constructive environment. The purpose of this effort was to quantify the impact of aircrew vision on an...simulated tasks requiring precise depth discrimination. This work will provide an example validation method for future stereoscopic virtual immersive

Employing WebGL to develop interactive stereoscopic 3D content for use in biomedical visualization

NASA Astrophysics Data System (ADS)

Johnston, Semay; Renambot, Luc; Sauter, Daniel

2013-03-01

Web Graphics Library (WebGL), the forthcoming web standard for rendering native 3D graphics in a browser, represents an important addition to the biomedical visualization toolset. It is projected to become a mainstream method of delivering 3D online content due to shrinking support for third-party plug-ins. Additionally, it provides a virtual reality (VR) experience to web users accommodated by the growing availability of stereoscopic displays (3D TV, desktop, and mobile). WebGL's value in biomedical visualization has been demonstrated by applications for interactive anatomical models, chemical and molecular visualization, and web-based volume rendering. However, a lack of instructional literature specific to the field prevents many from utilizing this technology. This project defines a WebGL design methodology for a target audience of biomedical artists with a basic understanding of web languages and 3D graphics. The methodology was informed by the development of an interactive web application depicting the anatomy and various pathologies of the human eye. The application supports several modes of stereoscopic displays for a better understanding of 3D anatomical structures.

Analysis of brain activity and response during monoscopic and stereoscopic visualization

NASA Astrophysics Data System (ADS)

Calore, Enrico; Folgieri, Raffaella; Gadia, Davide; Marini, Daniele

2012-03-01

Stereoscopic visualization in cinematography and Virtual Reality (VR) creates an illusion of depth by means of two bidimensional images corresponding to different views of a scene. This perceptual trick is used to enhance the emotional response and the sense of presence and immersivity of the observers. An interesting question is if and how it is possible to measure and analyze the level of emotional involvement and attention of the observers during a stereoscopic visualization of a movie or of a virtual environment. The research aims represent a challenge, due to the large number of sensorial, physiological and cognitive stimuli involved. In this paper we begin this research by analyzing possible differences in the brain activity of subjects during the viewing of monoscopic or stereoscopic contents. To this aim, we have performed some preliminary experiments collecting electroencephalographic (EEG) data of a group of users using a Brain- Computer Interface (BCI) during the viewing of stereoscopic and monoscopic short movies in a VR immersive installation.

Stereoscopic Projection in Organic Chemistry: Bridging the Gap between Two and Three Dimensions.

ERIC Educational Resources Information Center

Rozzelle, Arlene A.; Rosenfeld, Stuart M.

1985-01-01

Shows how to make stereo slides of three-dimensional molecular models. The slides have been used to teach chirality, conformational isomerism, how models and two-dimensional representations embody selected aspects of structure, and fundamentals of using the specific model set required in a particular organic chemistry course. (JN)

Visualization of planetary subsurface radar sounder data in three dimensions using stereoscopy

NASA Astrophysics Data System (ADS)

Frigeri, A.; Federico, C.; Pauselli, C.; Ercoli, M.; Coradini, A.; Orosei, R.

2010-12-01

Planetary subsurface sounding radar data extend the knowledge of planetary surfaces to a third dimension: the depth. The interpretation of delays of radar echoes converted into depth often requires the comparative analysis with other data, mainly topography, and radar data from different orbits can be used to investigate the spatial continuity of signals from subsurface geologic features. This scenario requires taking into account spatially referred information in three dimensions. Three dimensional objects are generally easier to understand if represented into a three dimensional space, and this representation can be improved by stereoscopic vision. Since its invention in the first half of 19th century, stereoscopy has been used in a broad range of application, including scientific visualization. The quick improvement of computer graphics and the spread of graphic rendering hardware allow to apply the basic principles of stereoscopy in the digital domain, allowing the stereoscopic projection of complex models. Specialized system for stereoscopic view of scientific data have been available in the industry, and proprietary solutions were affordable only to large research institutions. In the last decade, thanks to the GeoWall Consortium, the basics of stereoscopy have been applied for setting up stereoscopic viewers based on off-the shelf hardware products. Geowalls have been spread and are now used by several geo-science research institutes and universities. We are exploring techniques for visualizing planetary subsurface sounding radar data in three dimensions and we are developing a hardware system for rendering it in a stereoscopic vision system. Several Free Open Source Software tools and libraries are being used, as their level of interoperability is typically high and their licensing system offers the opportunity to implement quickly new functionalities to solve specific needs during the progress of the project. Visualization of planetary radar data in three dimensions represents a challenging task, and the exploration of different strategies will bring to the selection of the most appropriate ones for a meaningful extraction of information from the products of these innovative instruments.

Evaluation of stereoscopic video cameras synchronized with the movement of an operator's head on the teleoperation of the actual backhoe shovel

NASA Astrophysics Data System (ADS)

Minamoto, Masahiko; Matsunaga, Katsuya

1999-05-01

Operator performance while using a remote controlled backhoe shovel is described for three different stereoscopic viewing conditions: direct view, fixed stereoscopic cameras connected to a helmet mounted display (HMD), and rotating stereo camera connected and slaved to the head orientation of a free moving stereo HMD. Results showed that the head- slaved system provided the best performance.

Production and evaluation of stereoscopic video presentation in surgical training

NASA Astrophysics Data System (ADS)

Ilgner, Justus; Kawai, Takashi; Westhofen, Martin; Shibata, Takashi

2004-05-01

Stereoscopic video teaching can facilitate understanding for current minimally-invasive operative techniques. This project was created to set up a digital stereoscopic teaching environment for training of ENT residents and medical students. We recorded three ENT operative procedures (tympanoplasty, paranasal sinus operation and laser chordectomy) at the University Hospital Aachen. The material was edited stereoscopically at the Waseda University and converted into a streaming 3-D video format, which does not depend on PAL or NTSC signal standards. Video clips were evaluated by 5 ENT specialists and 11 residents in single sessions on an LCD monitor (8) and a CRT monitor (8). Emphasis was laid on depth perception, visual fatigue and time to achieve stereoscopic impression. Qualitative results were recorded on a visual analogue scale, ranging from 1 (excellent) to 5 (bad). The overall impression was rated 2,06 to 3,13 in the LCD group and 2,0 to 2,62 in the CRT group. The depth impression was rated 1,63 to 2,88 (LCD) and 1,63 to 2,25 (CRT). Stereoscopic video teaching was regarded as useful in ENT training by all participants. Further points for evaluation will be the quantification of depth information as well as the information gain in teaching junior colleagues.

Digital stereoscopic convergence where video games and movies for the home user meet

NASA Astrophysics Data System (ADS)

Schur, Ethan

2009-02-01

Today there is a proliferation of stereoscopic 3D display devices, 3D content, and 3D enabled video games. As we in the S-3D community bring stereoscopic 3D to the home user we have a real opportunity of using stereoscopic 3D to bridge the gap between exciting immersive games and home movies. But to do this, we cannot limit ourselves to current conceptions of gaming and movies. We need, for example, to imagine a movie that is fully rendered using avatars in a stereoscopic game environment. Or perhaps to imagine a pervasive drama where viewers can play too and become an essential part of the drama - whether at home or on the go on a mobile platform. Stereoscopic 3D is the "glue" that will bind these video and movie concepts together. As users feel more immersed, the lines between current media will blur. This means that we have the opportunity to shape the way that we, as humans, view and interact with each other, our surroundings and our most fundamental art forms. The goal of this paper is to stimulate conversation and further development on expanding the current gaming and home theatre infrastructures to support greatly-enhanced experiential entertainment.

Cosmic cookery: making a stereoscopic 3D animated movie

NASA Astrophysics Data System (ADS)

Holliman, Nick; Baugh, Carlton; Frenk, Carlos; Jenkins, Adrian; Froner, Barbara; Hassaine, Djamel; Helly, John; Metcalfe, Nigel; Okamoto, Takashi

2006-02-01

This paper describes our experience making a short stereoscopic movie visualizing the development of structure in the universe during the 13.7 billion years from the Big Bang to the present day. Aimed at a general audience for the Royal Society's 2005 Summer Science Exhibition, the movie illustrates how the latest cosmological theories based on dark matter and dark energy are capable of producing structures as complex as spiral galaxies and allows the viewer to directly compare observations from the real universe with theoretical results. 3D is an inherent feature of the cosmology data sets and stereoscopic visualization provides a natural way to present the images to the viewer, in addition to allowing researchers to visualize these vast, complex data sets. The presentation of the movie used passive, linearly polarized projection onto a 2m wide screen but it was also required to playback on a Sharp RD3D display and in anaglyph projection at venues without dedicated stereoscopic display equipment. Additionally lenticular prints were made from key images in the movie. We discuss the following technical challenges during the stereoscopic production process; 1) Controlling the depth presentation, 2) Editing the stereoscopic sequences, 3) Generating compressed movies in display specific formats. We conclude that the generation of high quality stereoscopic movie content using desktop tools and equipment is feasible. This does require careful quality control and manual intervention but we believe these overheads are worthwhile when presenting inherently 3D data as the result is significantly increased impact and better understanding of complex 3D scenes.

Jig For Stereoscopic Photography

NASA Technical Reports Server (NTRS)

Nielsen, David J.

1990-01-01

Separations between views adjusted precisely for best results. Simple jig adjusted to set precisely, distance between right and left positions of camera used to make stereoscopic photographs. Camera slides in slot between extreme positions, where it takes stereoscopic pictures. Distance between extreme positions set reproducibly with micrometer. In view of trend toward very-large-scale integration of electronic circuits, training method and jig used to make training photographs useful to many companies to reduce cost of training manufacturing personnel.

Acquisition of Stereoscopic Particle Image Velocimetry System for Investigation of Unsteady Flows

DTIC Science & Technology

2016-04-30

SECURITY CLASSIFICATION OF: The objective of the project titled “Acquisition of Stereoscopic Particle Image Velocimetry (S-PIV) System for...Distribution Unlimited UU UU UU UU 30-04-2016 1-Feb-2015 31-Jan-2016 Final Report: Acquisition of Stereoscopic Particle Image Velocimetry System For...ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Particle Image Velocimetry REPORT DOCUMENTATION PAGE 11

DWT-based stereoscopic image watermarking

NASA Astrophysics Data System (ADS)

Chammem, A.; Mitrea, M.; Pr"teux, F.

2011-03-01

Watermarking already imposed itself as an effective and reliable solution for conventional multimedia content protection (image/video/audio/3D). By persistently (robustly) and imperceptibly (transparently) inserting some extra data into the original content, the illegitimate use of data can be detected without imposing any annoying constraint to a legal user. The present paper deals with stereoscopic image protection by means of watermarking techniques. That is, we first investigate the peculiarities of the visual stereoscopic content from the transparency and robustness point of view. Then, we advance a new watermarking scheme designed so as to reach the trade-off between transparency and robustness while ensuring a prescribed quantity of inserted information. Finally, this method is evaluated on two stereoscopic image corpora (natural image and medical data).

Usage of stereoscopic visualization in the learning contents of rotational motion.

PubMed

Matsuura, Shu

2013-01-01

Rotational motion plays an essential role in physics even at an introductory level. In addition, the stereoscopic display of three-dimensional graphics includes is advantageous for the presentation of rotational motions, particularly for depth recognition. However, the immersive visualization of rotational motion has been known to lead to dizziness and even nausea for some viewers. Therefore, the purpose of this study is to examine the onset of nausea and visual fatigue when learning rotational motion through the use of a stereoscopic display. The findings show that an instruction method with intermittent exposure of the stereoscopic display and a simplification of its visual components reduced the onset of nausea and visual fatigue for the viewers, which maintained the overall effect of instantaneous spatial recognition.

Stereoscopic visual fatigue assessment and modeling

NASA Astrophysics Data System (ADS)

Wang, Danli; Wang, Tingting; Gong, Yue

2014-03-01

Evaluation of stereoscopic visual fatigue is one of the focuses in the user experience research. It is measured in either subjective or objective methods. Objective measures are more preferred for their capability to quantify the degree of human visual fatigue without being affected by individual variation. However, little research has been conducted on the integration of objective indicators, or the sensibility of each objective indicator in reflecting subjective fatigue. The paper proposes a simply effective method to evaluate visual fatigue more objectively. The stereoscopic viewing process is divided into series of sessions, after each of which viewers rate their visual fatigue with subjective scores (SS) according to a five-grading scale, followed by tests of the punctum maximum accommodation (PMA) and visual reaction time (VRT). Throughout the entire viewing process, their eye movements are recorded by an infrared camera. The pupil size (PS) and percentage of eyelid closure over the pupil over time (PERCLOS) are extracted from the videos processed by the algorithm. Based on the method, an experiment with 14 subjects was conducted to assess visual fatigue induced by 3D images on polarized 3D display. The experiment consisted of 10 sessions (5min per session), each containing the same 75 images displayed randomly. The results show that PMA, VRT and PERCLOS are the most efficient indicators of subjective visual fatigue and finally a predictive model is derived from the stepwise multiple regressions.

Diffuse nitrogen loss simulation and impact assessment of stereoscopic agriculture pattern by integrated water system model and consideration of multiple existence forms

NASA Astrophysics Data System (ADS)

Zhang, Yongyong; Gao, Yang; Yu, Qiang

2017-09-01

Agricultural nitrogen loss becomes an increasingly important source of water quality deterioration and eutrophication, even threatens water safety for humanity. Nitrogen dynamic mechanism is still too complicated to be well captured at watershed scale due to its multiple existence forms and instability, disturbance of agricultural management practices. Stereoscopic agriculture is a novel agricultural planting pattern to efficiently use local natural resources (e.g., water, land, sunshine, heat and fertilizer). It is widely promoted as a high yield system and can obtain considerable economic benefits, particularly in China. However, its environmental quality implication is not clear. In our study, Qianyanzhou station is famous for its stereoscopic agriculture pattern of Southern China, and an experimental watershed was selected as our study area. Regional characteristics of runoff and nitrogen losses were simulated by an integrated water system model (HEQM) with multi-objective calibration, and multiple agriculture practices were assessed to find the effective approach for the reduction of diffuse nitrogen losses. Results showed that daily variations of runoff and nitrogen forms were well reproduced throughout watershed, i.e., satisfactory performances for ammonium and nitrate nitrogen (NH4-N and NO3-N) loads, good performances for runoff and organic nitrogen (ON) load, and very good performance for total nitrogen (TN) load. The average loss coefficient was 62.74 kg/ha for NH4-N, 0.98 kg/ha for NO3-N, 0.0004 kg/ha for ON and 63.80 kg/ha for TN. The dominating form of nitrogen losses was NH4-N due to the applied fertilizers, and the most dramatic zones aggregated in the middle and downstream regions covered by paddy and orange orchard. In order to control diffuse nitrogen losses, the most effective practices for Qianyanzhou stereoscopic agriculture pattern were to reduce farmland planting scale in the valley by afforestation, particularly for orchard in the downstream regions, followed by fertilizer application optimization.

SRTM Stereo Pair with Landsat Overlay: Miquelon and Saint Pierre Islands

NASA Image and Video Library

2000-10-20

This stereoscopic satellite image showing Miquelon and Saint Pierre Islands, located south of Newfoundland, Canada, was generated by draping NASA Landsat satellite image over a preliminary Shuttle Radar Topography Mission SRTM elevation model.

Visualization of Stereoscopic Anatomic Models of the Paranasal Sinuses and Cervical Vertebrae from the Surgical and Procedural Perspective

ERIC Educational Resources Information Center

Chen, Jian; Smith, Andrew D.; Khan, Majid A.; Sinning, Allan R.; Conway, Marianne L.; Cui, Dongmei

2017-01-01

Recent improvements in three-dimensional (3D) virtual modeling software allows anatomists to generate high-resolution, visually appealing, colored, anatomical 3D models from computed tomography (CT) images. In this study, high-resolution CT images of a cadaver were used to develop clinically relevant anatomic models including facial skull, nasal…

YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

NASA Astrophysics Data System (ADS)

Schild, Jonas; Seele, Sven; Masuch, Maic

2012-03-01

Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

Subjective experiences of watching stereoscopic Avatar and U2 3D in a cinema

NASA Astrophysics Data System (ADS)

Pölönen, Monika; Salmimaa, Marja; Takatalo, Jari; Häkkinen, Jukka

2012-01-01

A stereoscopic 3-D version of the film Avatar was shown to 85 people who subsequently answered questions related to sickness, visual strain, stereoscopic image quality, and sense of presence. Viewing Avatar for 165 min induced some symptoms of visual strain and sickness, but the symptom levels remained low. A comparison between Avatar and previously published results for the film U2 3D showed that sickness and visual strain levels were similar despite the films' runtimes. The genre of the film had a significant effect on the viewers' opinions and sense of presence. Avatar, which has been described as a combination of action, adventure, and sci-fi genres, was experienced as more immersive and engaging than the music documentary U2 3D. However, participants in both studies were immersed, focused, and absorbed in watching the stereoscopic 3-D (S3-D) film and were pleased with the film environments. The results also showed that previous stereoscopic 3-D experience significantly reduced the amount of reported eye strain and complaints about the weight of the viewing glasses.

Instability of the perceived world while watching 3D stereoscopic imagery: A likely source of motion sickness symptoms

PubMed Central

Hwang, Alex D.; Peli, Eli

2014-01-01

Watching 3D content using a stereoscopic display may cause various discomforting symptoms, including eye strain, blurred vision, double vision, and motion sickness. Numerous studies have reported motion-sickness-like symptoms during stereoscopic viewing, but no causal linkage between specific aspects of the presentation and the induced discomfort has been explicitly proposed. Here, we describe several causes, in which stereoscopic capture, display, and viewing differ from natural viewing resulting in static and, importantly, dynamic distortions that conflict with the expected stability and rigidity of the real world. This analysis provides a basis for suggested changes to display systems that may alleviate the symptoms, and suggestions for future studies to determine the relative contribution of the various effects to the unpleasant symptoms. PMID:26034562

High-speed switchable lens enables the development of a volumetric stereoscopic display

PubMed Central

Love, Gordon D.; Hoffman, David M.; Hands, Philip J.W.; Gao, James; Kirby, Andrew K.; Banks, Martin S.

2011-01-01

Stereoscopic displays present different images to the two eyes and thereby create a compelling three-dimensional (3D) sensation. They are being developed for numerous applications including cinema, television, virtual prototyping, and medical imaging. However, stereoscopic displays cause perceptual distortions, performance decrements, and visual fatigue. These problems occur because some of the presented depth cues (i.e., perspective and binocular disparity) specify the intended 3D scene while focus cues (blur and accommodation) specify the fixed distance of the display itself. We have developed a stereoscopic display that circumvents these problems. It consists of a fast switchable lens synchronized to the display such that focus cues are nearly correct. The system has great potential for both basic vision research and display applications. PMID:19724571

The Effects of Actual Human Size Display and Stereoscopic Presentation on Users' Sense of Being Together with and of Psychological Immersion in a Virtual Character

PubMed Central

Ahn, Dohyun; Seo, Youngnam; Kim, Minkyung; Kwon, Joung Huem; Jung, Younbo; Ahn, Jungsun

2014-01-01

Abstract This study examined the role of display size and mode in increasing users' sense of being together with and of their psychological immersion in a virtual character. Using a high-resolution three-dimensional virtual character, this study employed a 2×2 (stereoscopic mode vs. monoscopic mode×actual human size vs. small size display) factorial design in an experiment with 144 participants randomly assigned to each condition. Findings showed that stereoscopic mode had a significant effect on both users' sense of being together and psychological immersion. However, display size affected only the sense of being together. Furthermore, display size was not found to moderate the effect of stereoscopic mode. PMID:24606057

SEISVIZ3D: Stereoscopic system for the representation of seismic data - Interpretation and Immersion

NASA Astrophysics Data System (ADS)

von Hartmann, Hartwig; Rilling, Stefan; Bogen, Manfred; Thomas, Rüdiger

2015-04-01

The seismic method is a valuable tool for getting 3D-images from the subsurface. Seismic data acquisition today is not only a topic for oil and gas exploration but is used also for geothermal exploration, inspections of nuclear waste sites and for scientific investigations. The system presented in this contribution may also have an impact on the visualization of 3D-data of other geophysical methods. 3D-seismic data can be displayed in different ways to give a spatial impression of the subsurface.They are a combination of individual vertical cuts, possibly linked to a cubical portion of the data volume, and the stereoscopic view of the seismic data. By these methods, the spatial perception for the structures and thus of the processes in the subsurface should be increased. Stereoscopic techniques are e. g. implemented in the CAVE and the WALL, both of which require a lot of space and high technical effort. The aim of the interpretation system shown here is stereoscopic visualization of seismic data at the workplace, i.e. at the personal workstation and monitor. The system was developed with following criteria in mind: • Fast rendering of large amounts of data so that a continuous view of the data when changing the viewing angle and the data section is possible, • defining areas in stereoscopic view to translate the spatial impression directly into an interpretation, • the development of an appropriate user interface, including head-tracking, for handling the increased degrees of freedom, • the possibility of collaboration, i.e. teamwork and idea exchange with the simultaneous viewing of a scene at remote locations. The possibilities offered by the use of a stereoscopic system do not replace a conventional interpretation workflow. Rather they have to be implemented into it as an additional step. The amplitude distribution of the seismic data is a challenge for the stereoscopic display because the opacity level and the scaling and selection of the data have to fit to each other. Also the data selection may depend on the visualization task. Not only can the amplitude data be used but also different seismic attribute transformations. The development is supplemented by interviews, to analyse the efficiency and manageability of the stereoscopic workplace environment. Another point of investigation is the immersion, i.e. the increased concentration on the observed scene when passing through the data, triggered by the stereoscopic viewing. This effect is reinforced by a user interface which is so intuitive and simple that it does not draw attention away from the scene. For the seismic interpretation purpose the stereoscopic view supports the pattern recognition of geological structures and the detection of their spatial heterogeneity. These are topics which are relevant for the actual geothermal exploration in Germany.

Stereoscopic visualization and haptic technology used to create a virtual environment for remote surgery - biomed 2011.

PubMed

Bornhoft, J M; Strabala, K W; Wortman, T D; Lehman, A C; Oleynikov, D; Farritor, S M

2011-01-01

The objective of this research is to study the effectiveness of using a stereoscopic visualization system for performing remote surgery. The use of stereoscopic vision has become common with the advent of the da Vinci® system (Intuitive, Sunnyvale CA). This system creates a virtual environment that consists of a 3-D display for visual feedback and haptic tactile feedback, together providing an intuitive environment for remote surgical applications. This study will use simple in vivo robotic surgical devices and compare the performance of surgeons using the stereoscopic interfacing system to the performance of surgeons using one dimensional monitors. The stereoscopic viewing system consists of two cameras, two monitors, and four mirrors. The cameras are mounted to a multi-functional miniature in vivo robot; and mimic the depth perception of the actual human eyes. This is done by placing the cameras at a calculated angle and distance apart. Live video streams from the left and right cameras are displayed on the left and right monitors, respectively. A system of angled mirrors allows the left and right eyes to see the video stream from the left and right monitor, respectively, creating the illusion of depth. The haptic interface consists of two PHANTOM Omni® (SensAble, Woburn Ma) controllers. These controllers measure the position and orientation of a pen-like end effector with three degrees of freedom. As the surgeon uses this interface, they see a 3-D image and feel force feedback for collision and workspace limits. The stereoscopic viewing system has been used in several surgical training tests and shows a potential improvement in depth perception and 3-D vision. The haptic system accurately gives force feedback that aids in surgery. Both have been used in non-survival animal surgeries, and have successfully been used in suturing and gallbladder removal. Bench top experiments using the interfacing system have also been conducted. A group of participants completed two different surgical training tasks using both a two dimensional visual system and the stereoscopic visual system. Results suggest that the stereoscopic visual system decreased the amount of time taken to complete the tasks. All participants also reported that the stereoscopic system was easier to utilize than the two dimensional system. Haptic controllers combined with stereoscopic vision provides for a more intuitive virtual environment. This system provides the surgeon with 3-D vision, depth perception, and the ability to receive feedback through forces applied in the haptic controller while performing surgery. These capabilities potentially enable the performance of more complex surgeries with a higher level of precision.

Perceptual asymmetry reveals neural substrates underlying stereoscopic transparency.

PubMed

Tsirlin, Inna; Allison, Robert S; Wilcox, Laurie M

2012-02-01

We describe a perceptual asymmetry found in stereoscopic perception of overlaid random-dot surfaces. Specifically, the minimum separation in depth needed to perceptually segregate two overlaid surfaces depended on the distribution of dots across the surfaces. With the total dot density fixed, significantly larger inter-plane disparities were required for perceptual segregation of the surfaces when the front surface had fewer dots than the back surface compared to when the back surface was the one with fewer dots. We propose that our results reflect an asymmetry in the signal strength of the front and back surfaces due to the assignment of the spaces between the dots to the back surface by disparity interpolation. This hypothesis was supported by the results of two experiments designed to reduce the imbalance in the neuronal response to the two surfaces. We modeled the psychophysical data with a network of inter-neural connections: excitatory within-disparity and inhibitory across disparity, where the spread of disparity was modulated according to figure-ground assignment. These psychophysical and computational findings suggest that stereoscopic transparency depends on both inter-neural interactions of disparity-tuned cells and higher-level processes governing figure ground segregation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Passive method of eliminating accommodation/convergence disparity in stereoscopic head-mounted displays

NASA Astrophysics Data System (ADS)

Eichenlaub, Jesse B.

2005-03-01

The difference in accommodation and convergence distance experienced when viewing stereoscopic displays has long been recognized as a source of visual discomfort. It is especially problematic in head mounted virtual reality and enhanced reality displays, where images must often be displayed across a large depth range or superimposed on real objects. DTI has demonstrated a novel method of creating stereoscopic images in which the focus and fixation distances are closely matched for all parts of the scene from close distances to infinity. The method is passive in the sense that it does not rely on eye tracking, moving parts, variable focus optics, vibrating optics, or feedback loops. The method uses a rapidly changing illumination pattern in combination with a high speed microdisplay to create cones of light that converge at different distances to form the voxels of a high resolution space filling image. A bench model display was built and a series of visual tests were performed in order to demonstrate the concept and investigate both its capabilities and limitations. Results proved conclusively that real optical images were being formed and that observers had to change their focus to read text or see objects at different distances

Recent developments in stereoscopic and holographic 3D display technologies

NASA Astrophysics Data System (ADS)

Sarma, Kalluri

2014-06-01

Currently, there is increasing interest in the development of high performance 3D display technologies to support a variety of applications including medical imaging, scientific visualization, gaming, education, entertainment, air traffic control and remote operations in 3D environments. In this paper we will review the attributes of the various 3D display technologies including stereoscopic and holographic 3D, human factors issues of stereoscopic 3D, the challenges in realizing Holographic 3D displays and the recent progress in these technologies.

Case study: using a stereoscopic display for mission planning

NASA Astrophysics Data System (ADS)

Kleiber, Michael; Winkelholz, Carsten

2009-02-01

This paper reports on the results of a study investigating the benefits of using an autostereoscopic display in the training targeting process of the Germain Air Force. The study examined how stereoscopic 3D visualizations can help to improve flight path planning and the preparation of a mission in general. An autostereoscopic display was used because it allows the operator to perceive the stereoscopic images without shutter glasses which facilitates the integration into a workplace with conventional 2D monitors and arbitrary lighting conditions.

Molecular Dynamics Visualization (MDV): Stereoscopic 3D Display of Biomolecular Structure and Interactions Using the Unity Game Engine.

PubMed

Wiebrands, Michael; Malajczuk, Chris J; Woods, Andrew J; Rohl, Andrew L; Mancera, Ricardo L

2018-06-21

Molecular graphics systems are visualization tools which, upon integration into a 3D immersive environment, provide a unique virtual reality experience for research and teaching of biomolecular structure, function and interactions. We have developed a molecular structure and dynamics application, the Molecular Dynamics Visualization tool, that uses the Unity game engine combined with large scale, multi-user, stereoscopic visualization systems to deliver an immersive display experience, particularly with a large cylindrical projection display. The application is structured to separate the biomolecular modeling and visualization systems. The biomolecular model loading and analysis system was developed as a stand-alone C# library and provides the foundation for the custom visualization system built in Unity. All visual models displayed within the tool are generated using Unity-based procedural mesh building routines. A 3D user interface was built to allow seamless dynamic interaction with the model while being viewed in 3D space. Biomolecular structure analysis and display capabilities are exemplified with a range of complex systems involving cell membranes, protein folding and lipid droplets.

Hands-on guide for 3D image creation for geological purposes

NASA Astrophysics Data System (ADS)

Frehner, Marcel; Tisato, Nicola

2013-04-01

Geological structures in outcrops or hand specimens are inherently three dimensional (3D), and therefore better understandable if viewed in 3D. While 3D models can easily be created, manipulated, and looked at from all sides on the computer screen (e.g., using photogrammetry or laser scanning data), 3D visualizations for publications or conference posters are much more challenging as they have to live in a 2D-world (i.e., on a sheet of paper). Perspective 2D visualizations of 3D models do not fully transmit the "feeling and depth of the third dimension" to the audience; but this feeling is desirable for a better examination and understanding in 3D of the structure under consideration. One of the very few possibilities to generate real 3D images, which work on a 2D display, is by using so-called stereoscopic images. Stereoscopic images are two images of the same object recorded from two slightly offset viewpoints. Special glasses and techniques have to be used to make sure that one image is seen only by one eye, and the other image is seen by the other eye, which together lead to the "3D effect". Geoscientists are often familiar with such 3D images. For example, geomorphologists traditionally view stereographic orthophotos by employing a mirror-steroscope. Nowadays, petroleum-geoscientists examine high-resolution 3D seismic data sets in special 3D visualization rooms. One of the methods for generating and viewing a stereoscopic image, which does not require a high-tech viewing device, is to create a so-called anaglyph. The principle is to overlay two images saturated in red and cyan, respectively. The two images are then viewed through red-cyan-stereoscopic glasses. This method is simple and cost-effective, but has some drawbacks in preserving colors accurately. A similar method is used in 3D movies, where polarized light or shuttering techniques are used to separate the left from the right image, which allows preserving the original colors. The advantage of red-cyan anaglyphs is their simplicity and the possibility to print them on normal paper or project them using a conventional projector. Producing 3D stereoscopic images is much easier than commonly thought. Our hands-on poster provides an easy-to-use guide for producing 3D stereoscopic images. Few simple rules-of-thumb are presented that define how photographs of any scene or object have to be shot to produce good-looking 3D images. We use the free software Stereophotomaker (http://stereo.jpn.org/eng/stphmkr) to produce anaglyphs and provide red-cyan 3D glasses for viewing them. Our hands-on poster is easy to adapt and helps any geologist to present his/her field or hand specimen photographs in a much more fashionable 3D way for future publications or conference posters.

Explorable Three-Dimensional Digital Model of the Female Pelvis, Pelvic Contents, and Perineum for Anatomical Education

ERIC Educational Resources Information Center

Sergovich, Aimee; Johnson, Marjorie; Wilson, Timothy D.

2010-01-01

The anatomy of the pelvis is complex, multilayered, and its three-dimensional organization is conceptually difficult for students to grasp. The aim of this project was to create an explorable and projectable stereoscopic, three-dimensional (3D) model of the female pelvis and pelvic contents for anatomical education. The model was created using…

Enduring stereoscopic motion aftereffects induced by prolonged adaptation.

PubMed

Bowd, C; Rose, D; Phinney, R E; Patterson, R

1996-11-01

This study investigated the effects of prolonged adaptation on the recovery of the stereoscopic motion aftereffect (adaptation induced by moving binocular disparity information). The adapting and test stimuli were stereoscopic grating patterns created from disparity, embedded in dynamic random-dot stereograms. Motion aftereffects induced by luminance stimuli were included in the study for comparison. Adaptation duration was either 1, 2, 4, 8, 16, 32 or 64 min and the duration of the ensuing aftereffect was the variable of interest. The results showed that aftereffect duration was proportional to the square root of adaptation duration for both stereoscopic and luminance stimuli; on log-log axes, the relation between aftereffect duration and adaptation duration was a power law with the slope near 0.5 in both cases. For both kinds of stimuli, there was no sign of adaptation saturation even at the longest adaptation duration.

Stereoscopic Viewing Can Induce Changes in the CA/C Ratio.

PubMed

Neveu, Pascaline; Roumes, Corinne; Philippe, Matthieu; Fuchs, Philippe; Priot, Anne-Emmanuelle

2016-08-01

Stereoscopic displays challenge the neural cross-coupling between accommodation and vergence by inducing a constant accommodative demand and a varying vergence demand. Stereoscopic viewing calls for a decrease in the gain of vergence accommodation, which is the accommodation caused by vergence, quantified by using the convergence-accommodation to convergence (CA/C) ratio. However, its adaptability is still a subject of debate. Cross-coupling (CA/C and AC/A ratios) and tonic components of vergence and accommodation were assessed in 12 participants (27.5 ± 5 years, stereoacuity better than 60 arc seconds, 6/6 acuity with corrected refractive error) before and after a 20-minute exposure to stereoscopic viewing. During stimulation, vergence demand oscillated from 1 to 3 meter angles along a virtual sagittal line in sinusoidal movements, while accommodative demand was fixed at 1.5 diopters. Results showed a decreased CA/C ratio (-10.36%, df = 10, t = 2.835, P = 0.018), with no change in the AC/A ratio (P = 0.090), tonic vergence (P = 0.708), and tonic accommodation (P = 0.493). These findings demonstrated that the CA/C ratio can exhibit adaptive adjustments. The observed nature and amount of the oculomotor modification failed to compensate for the stereoscopic constraint.

The relationship between three-dimensional imaging and group decision making: an exploratory study.

PubMed

Litynski, D M; Grabowski, M; Wallace, W A

1997-07-01

This paper describes an empirical investigation of the effect of three dimensional (3-D) imaging on group performance in a tactical planning task. The objective of the study is to examine the role that stereoscopic imaging can play in supporting face-to-face group problem solving and decision making-in particular, the alternative generation and evaluation processes in teams. It was hypothesized that with the stereoscopic display, group members would better visualize the information concerning the task environment, producing open communication and information exchanges. The experimental setting was a tactical command and control task, and the quality of the decisions and nature of the group decision process were investigated with three treatments: 1) noncomputerized, i.e., topographic maps with depth cues; 2) two-dimensional (2-D) imaging; and 3) stereoscopic imaging. The results were mixed on group performance. However, those groups with the stereoscopic displays generated more alternatives and spent less time on evaluation. In addition, the stereoscopic decision aid did not interfere with the group problem solving and decision-making processes. The paper concludes with a discussion of potential benefits, and the need to resolve demonstrated weaknesses of the technology.

Change Blindness Phenomena for Virtual Reality Display Systems.

PubMed

Steinicke, Frank; Bruder, Gerd; Hinrichs, Klaus; Willemsen, Pete

2011-09-01

In visual perception, change blindness describes the phenomenon that persons viewing a visual scene may apparently fail to detect significant changes in that scene. These phenomena have been observed in both computer-generated imagery and real-world scenes. Several studies have demonstrated that change blindness effects occur primarily during visual disruptions such as blinks or saccadic eye movements. However, until now the influence of stereoscopic vision on change blindness has not been studied thoroughly in the context of visual perception research. In this paper, we introduce change blindness techniques for stereoscopic virtual reality (VR) systems, providing the ability to substantially modify a virtual scene in a manner that is difficult for observers to perceive. We evaluate techniques for semiimmersive VR systems, i.e., a passive and active stereoscopic projection system as well as an immersive VR system, i.e., a head-mounted display, and compare the results to those of monoscopic viewing conditions. For stereoscopic viewing conditions, we found that change blindness phenomena occur with the same magnitude as in monoscopic viewing conditions. Furthermore, we have evaluated the potential of the presented techniques for allowing abrupt, and yet significant, changes of a stereoscopically displayed virtual reality environment.

Teaching-learning: stereoscopic 3D versus Traditional methods in Mexico City.

PubMed

Mendoza Oropeza, Laura; Ortiz Sánchez, Ricardo; Ojeda Villagómez, Raúl

2015-01-01

In the UNAM Faculty of Odontology, we use a stereoscopic 3D teaching method that has grown more common in the last year, which makes it important to know whether students can learn better with this strategy. The objective of the study is to know, if the 4th year students of the bachelor's degree in dentistry learn more effectively with the use of stereoscopic 3D than the traditional method in Orthodontics. first, we selected the course topics, to be used for both methods; the traditional method using projection of slides and for the stereoscopic third dimension, with the use of videos in digital stereo projection (seen through "passive" polarized 3D glasses). The main topic was supernumerary teeth, including and diverted from their guide eruption. Afterwards we performed an exam on students, containing 24 items, validated by expert judgment in Orthodontics teaching. The results of the data were compared between the two educational methods for determined effectiveness using the model before and after measurement with the statistical package SPSS 20 version. The results presented for the 9 groups of undergraduates in dentistry, were collected with a total of 218 students for 3D and traditional methods, we found in a traditional method a mean 4.91, SD 1.4752 in the pretest and X=6.96, SD 1.26622, St Error 0.12318 for the posttest. The 3D method had a mean 5.21, SD 1.996779 St Error 0.193036 for the pretest X= 7.82, SD =0.963963, St Error 0.09319 posttest; the analysis of Variance between groups F= 5.60 Prob > 0.0000 and Bartlett's test for equal variances 21.0640 Prob > chi² = 0.007. These results show that the student's learning in 3D means a significant improvement as compared to the traditional teaching method and having a strong association between the two methods. The findings suggest that the stereoscopic 3D method lead to improved student learning compared to traditional teaching.

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.

Investigation of 1 : 1,000 Scale Map Generation by Stereo Plotting Using Uav Images

NASA Astrophysics Data System (ADS)

Rhee, S.; Kim, T.

2017-08-01

Large scale maps and image mosaics are representative geospatial data that can be extracted from UAV images. Map drawing using UAV images can be performed either by creating orthoimages and digitizing them, or by stereo plotting. While maps generated by digitization may serve the need for geospatial data, many institutions and organizations require map drawing using stereoscopic vision on stereo plotting systems. However, there are several aspects to be checked for UAV images to be utilized for stereo plotting. The first aspect is the accuracy of exterior orientation parameters (EOPs) generated through automated bundle adjustment processes. It is well known that GPS and IMU sensors mounted on a UAV are not very accurate. It is necessary to adjust initial EOPs accurately using tie points. For this purpose, we have developed a photogrammetric incremental bundle adjustment procedure. The second aspect is unstable shooting conditions compared to aerial photographing. Unstable image acquisition may bring uneven stereo coverage, which will result in accuracy loss eventually. Oblique stereo pairs will create eye fatigue. The third aspect is small coverage of UAV images. This aspect will raise efficiency issue for stereo plotting of UAV images. More importantly, this aspect will make contour generation from UAV images very difficult. This paper will discuss effects relate to these three aspects. In this study, we tried to generate 1 : 1,000 scale map from the dataset using EOPs generated from software developed in-house. We evaluated Y-disparity of the tie points extracted automatically through the photogrammetric incremental bundle adjustment process. We could confirm that stereoscopic viewing is possible. Stereoscopic plotting work was carried out by a professional photogrammetrist. In order to analyse the accuracy of the map drawing using stereoscopic vision, we compared the horizontal and vertical position difference between adjacent models after drawing a specific model. The results of analysis showed that the errors were within the specification of 1 : 1,000 map. Although the Y-parallax can be eliminated, it is still necessary to improve the accuracy of absolute ground position error in order to apply this technique to the actual work. There are a few models in which the difference in height between adjacent models is about 40 cm. We analysed the stability of UAV images by checking angle differences between adjacent images. We also analysed the average area covered by one stereo model and discussed the possible difficulty associated with this narrow coverage. In the future we consider how to reduce position errors and improve map drawing performances from UAVs.

The compressed average image intensity metric for stereoscopic video quality assessment

NASA Astrophysics Data System (ADS)

Wilczewski, Grzegorz

2016-09-01

The following article depicts insights towards design, creation and testing of a genuine metric designed for a 3DTV video quality evaluation. The Compressed Average Image Intensity (CAII) mechanism is based upon stereoscopic video content analysis, setting its core feature and functionality to serve as a versatile tool for an effective 3DTV service quality assessment. Being an objective type of quality metric it may be utilized as a reliable source of information about the actual performance of a given 3DTV system, under strict providers evaluation. Concerning testing and the overall performance analysis of the CAII metric, the following paper presents comprehensive study of results gathered across several testing routines among selected set of samples of stereoscopic video content. As a result, the designed method for stereoscopic video quality evaluation is investigated across the range of synthetic visual impairments injected into the original video stream.

Analysis on the 3D crosstalk in stereoscopic display

NASA Astrophysics Data System (ADS)

Choi, Hee-Jin

2010-11-01

Nowadays, with the rapid progresses in flat panel display (FPD) technologies, the three-dimensional (3D) display is now becoming a next mainstream of display market. Among the various 3D display techniques, the stereoscopic 3D display shows different left/right images for each eye of observer using special glasses and is the most popular 3D technique with the advantages of low price and high 3D resolution. However, current stereoscopic 3D displays suffer with the 3D crosstalk which means the interference between the left eye mage and right eye images since it degrades the quality of 3D image severely. In this paper, the meaning and causes of the 3D crosstalk in stereoscopic 3D display are introduced and the pre-proposed methods of 3D crosstalk measurement vision science are reviewed. Based on them The threshold of 3D crosstalk to realize a 3D display with no degradation is analyzed.

Towards An Understanding of Mobile Touch Navigation in a Stereoscopic Viewing Environment for 3D Data Exploration.

PubMed

López, David; Oehlberg, Lora; Doger, Candemir; Isenberg, Tobias

2016-05-01

We discuss touch-based navigation of 3D visualizations in a combined monoscopic and stereoscopic viewing environment. We identify a set of interaction modes, and a workflow that helps users transition between these modes to improve their interaction experience. In our discussion we analyze, in particular, the control-display space mapping between the different reference frames of the stereoscopic and monoscopic displays. We show how this mapping supports interactive data exploration, but may also lead to conflicts between the stereoscopic and monoscopic views due to users' movement in space; we resolve these problems through synchronization. To support our discussion, we present results from an exploratory observational evaluation with domain experts in fluid mechanics and structural biology. These experts explored domain-specific datasets using variations of a system that embodies the interaction modes and workflows; we report on their interactions and qualitative feedback on the system and its workflow.

Evaluating visual discomfort in stereoscopic projection-based CAVE system with a close viewing distance

NASA Astrophysics Data System (ADS)

Song, Weitao; Weng, Dongdong; Feng, Dan; Li, Yuqian; Liu, Yue; Wang, Yongtian

2015-05-01

As one of popular immersive Virtual Reality (VR) systems, stereoscopic cave automatic virtual environment (CAVE) system is typically consisted of 4 to 6 3m-by-3m sides of a room made of rear-projected screens. While many endeavors have been made to reduce the size of the projection-based CAVE system, the issue of asthenopia caused by lengthy exposure to stereoscopic images in such CAVE with a close viewing distance was seldom tangled. In this paper, we propose a light-weighted approach which utilizes a convex eyepiece to reduce visual discomfort induced by stereoscopic vision. An empirical experiment was conducted to examine the feasibility of convex eyepiece in a large depth of field (DOF) at close viewing distance both objectively and subjectively. The result shows the positive effects of convex eyepiece on the relief of eyestrain.

Comparison of form in potential functions while maintaining upright posture during exposure to stereoscopic video clips.

PubMed

Kutsuna, Kenichiro; Matsuura, Yasuyuki; Fujikake, Kazuhiro; Miyao, Masaru; Takada, Hiroki

2013-01-01

Visually induced motion sickness (VIMS) is caused by sensory conflict, the disagreement between vergence and visual accommodation while observing stereoscopic images. VIMS can be measured by psychological and physiological methods. We propose a mathematical methodology to measure the effect of three-dimensional (3D) images on the equilibrium function. In this study, body sway in the resting state is compared with that during exposure to 3D video clips on a liquid crystal display (LCD) and on a head mounted display (HMD). In addition, the Simulator Sickness Questionnaire (SSQ) was completed immediately afterward. Based on the statistical analysis of the SSQ subscores and each index for stabilograms, we succeeded in determining the quantity of the VIMS during exposure to the stereoscopic images. Moreover, we discuss the metamorphism in the potential functions to control the standing posture during the exposure to stereoscopic video clips.

Effect of the accommodation-vergence conflict on vergence eye movements.

PubMed

Vienne, Cyril; Sorin, Laurent; Blondé, Laurent; Huynh-Thu, Quan; Mamassian, Pascal

2014-07-01

With the broader use of stereoscopic displays, a flurry of research activity about the accommodation-vergence conflict has emerged to highlight the implications for the human visual system. In stereoscopic displays, the introduction of binocular disparities requires the eyes to make vergence movements. In this study, we examined vergence dynamics with regard to the conflict between the stimulus-to-accommodation and the stimulus-to-vergence. In a first experiment, we evaluated the immediate effect of the conflict on vergence responses by presenting stimuli with conflicting disparity and focus on a stereoscopic display (i.e. increasing the stereoscopic demand) or by presenting stimuli with matched disparity and focus using an arrangement of displays and a beam splitter (i.e. focus and disparity specifying the same locations). We found that the dynamics of vergence responses were slower overall in the first case due to the conflict between accommodation and vergence. In a second experiment, we examined the effect of a prolonged exposure to the accommodation-vergence conflict on vergence responses, in which participants judged whether an oscillating depth pattern was in front or behind the fixation plane. An increase in peak velocity was observed, thereby suggesting that the vergence system has adapted to the stereoscopic demand. A slight increase in vergence latency was also observed, thus indicating a small decline of vergence performance. These findings offer a better understanding and document how the vergence system behaves in stereoscopic displays. We describe what stimuli in stereo-movies might produce these oculomotor effects, and discuss potential applications perspectives. Copyright © 2014 Elsevier B.V. All rights reserved.

Stereoscopic camera and viewing systems with undistorted depth presentation and reduced or eliminated erroneous acceleration and deceleration perceptions, or with perceptions produced or enhanced for special effects

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor)

1991-01-01

Methods for providing stereoscopic image presentation and stereoscopic configurations using stereoscopic viewing systems having converged or parallel cameras may be set up to reduce or eliminate erroneously perceived accelerations and decelerations by proper selection of parameters, such as an image magnification factor, q, and intercamera distance, 2w. For converged cameras, q is selected to be equal to Ve - qwl = 0, where V is the camera distance, e is half the interocular distance of an observer, w is half the intercamera distance, and l is the actual distance from the first nodal point of each camera to the convergence point, and for parallel cameras, q is selected to be equal to e/w. While converged cameras cannot be set up to provide fully undistorted three-dimensional views, they can be set up to provide a linear relationship between real and apparent depth and thus minimize erroneously perceived accelerations and decelerations for three sagittal planes, x = -w, x = 0, and x = +w which are indicated to the observer. Parallel cameras can be set up to provide fully undistorted three-dimensional views by controlling the location of the observer and by magnification and shifting of left and right images. In addition, the teachings of this disclosure can be used to provide methods of stereoscopic image presentation and stereoscopic camera configurations to produce a nonlinear relation between perceived and real depth, and erroneously produce or enhance perceived accelerations and decelerations in order to provide special effects for entertainment, training, or educational purposes.

Visual fatigue modeling for stereoscopic video shot based on camera motion

NASA Astrophysics Data System (ADS)

Shi, Guozhong; Sang, Xinzhu; Yu, Xunbo; Liu, Yangdong; Liu, Jing

2014-11-01

As three-dimensional television (3-DTV) and 3-D movie become popular, the discomfort of visual feeling limits further applications of 3D display technology. The cause of visual discomfort from stereoscopic video conflicts between accommodation and convergence, excessive binocular parallax, fast motion of objects and so on. Here, a novel method for evaluating visual fatigue is demonstrated. Influence factors including spatial structure, motion scale and comfortable zone are analyzed. According to the human visual system (HVS), people only need to converge their eyes to the specific objects for static cameras and background. Relative motion should be considered for different camera conditions determining different factor coefficients and weights. Compared with the traditional visual fatigue prediction model, a novel visual fatigue predicting model is presented. Visual fatigue degree is predicted using multiple linear regression method combining with the subjective evaluation. Consequently, each factor can reflect the characteristics of the scene, and the total visual fatigue score can be indicated according to the proposed algorithm. Compared with conventional algorithms which ignored the status of the camera, our approach exhibits reliable performance in terms of correlation with subjective test results.

A 3-D mixed-reality system for stereoscopic visualization of medical dataset.

PubMed

Ferrari, Vincenzo; Megali, Giuseppe; Troia, Elena; Pietrabissa, Andrea; Mosca, Franco

2009-11-01

We developed a simple, light, and cheap 3-D visualization device based on mixed reality that can be used by physicians to see preoperative radiological exams in a natural way. The system allows the user to see stereoscopic "augmented images," which are created by mixing 3-D virtual models of anatomies obtained by processing preoperative volumetric radiological images (computed tomography or MRI) with real patient live images, grabbed by means of cameras. The interface of the system consists of a head-mounted display equipped with two high-definition cameras. Cameras are mounted in correspondence of the user's eyes and allow one to grab live images of the patient with the same point of view of the user. The system does not use any external tracker to detect movements of the user or the patient. The movements of the user's head and the alignment of virtual patient with the real one are done using machine vision methods applied on pairs of live images. Experimental results, concerning frame rate and alignment precision between virtual and real patient, demonstrate that machine vision methods used for localization are appropriate for the specific application and that systems based on stereoscopic mixed reality are feasible and can be proficiently adopted in clinical practice.

Programming standards for effective S-3D game development

NASA Astrophysics Data System (ADS)

Schneider, Neil; Matveev, Alexander

2008-02-01

When a video game is in development, more often than not it is being rendered in three dimensions - complete with volumetric depth. It's the PC monitor that is taking this three-dimensional information, and artificially displaying it in a flat, two-dimensional format. Stereoscopic drivers take the three-dimensional information captured from DirectX and OpenGL calls and properly display it with a unique left and right sided view for each eye so a proper stereoscopic 3D image can be seen by the gamer. The two-dimensional limitation of how information is displayed on screen has encouraged programming short-cuts and work-arounds that stifle this stereoscopic 3D effect, and the purpose of this guide is to outline techniques to get the best of both worlds. While the programming requirements do not significantly add to the game development time, following these guidelines will greatly enhance your customer's stereoscopic 3D experience, increase your likelihood of earning Meant to be Seen certification, and give you instant cost-free access to the industry's most valued consumer base. While this outline is mostly based on NVIDIA's programming guide and iZ3D resources, it is designed to work with all stereoscopic 3D hardware solutions and is not proprietary in any way.

Characterization of crosstalk in stereoscopic display devices.

PubMed

Zafar, Fahad; Badano, Aldo

2014-12-01

Many different types of stereoscopic display devices are used for commercial and research applications. Stereoscopic displays offer the potential to improve performance in detection tasks for medical imaging diagnostic systems. Due to the variety of stereoscopic display technologies, it remains unclear how these compare with each other for detection and estimation tasks. Different stereo devices have different performance trade-offs due to their display characteristics. Among them, crosstalk is known to affect observer perception of 3D content and might affect detection performance. We measured and report the detailed luminance output and crosstalk characteristics for three different types of stereoscopic display devices. We recorded the effect of other issues on recorded luminance profiles such as viewing angle, use of different eye wear, and screen location. Our results show that the crosstalk signature for viewing 3D content can vary considerably when using different types of 3D glasses for active stereo displays. We also show that significant differences are present in crosstalk signatures when varying the viewing angle from 0 degrees to 20 degrees for a stereo mirror 3D display device. Our detailed characterization can help emulate the effect of crosstalk in conducting computational observer image quality assessment evaluations that minimize costly and time-consuming human reader studies.

[Evaluation of Motion Sickness Induced by 3D Video Clips].

PubMed

Matsuura, Yasuyuki; Takada, Hiroki

2016-01-01

The use of stereoscopic images has been spreading rapidly. Nowadays, stereoscopic movies are nothing new to people. Stereoscopic systems date back to 280 A.D. when Euclid first recognized the concept of depth perception by humans. Despite the increase in the production of three-dimensional (3D) display products and many studies on stereoscopic vision, the effect of stereoscopic vision on the human body has been insufficiently understood. However, symptoms such as eye fatigue and 3D sickness have been the concerns when viewing 3D films for a prolonged period of time; therefore, it is important to consider the safety of viewing virtual 3D contents as a contribution to society. It is generally explained to the public that accommodation and convergence are mismatched during stereoscopic vision and that this is the main reason for the visual fatigue and visually induced motion sickness (VIMS) during 3D viewing. We have devised a method to simultaneously measure lens accommodation and convergence. We used this simultaneous measurement device to characterize 3D vision. Fixation distance was compared between accommodation and convergence during the viewing of 3D films with repeated measurements. Time courses of these fixation distances and their distributions were compared in subjects who viewed 2D and 3D video clips. The results indicated that after 90 s of continuously viewing 3D images, the accommodative power does not correspond to the distance of convergence. In this paper, remarks on methods to measure the severity of motion sickness induced by viewing 3D films are also given. From the epidemiological viewpoint, it is useful to obtain novel knowledge for reduction and/or prevention of VIMS. We should accumulate empirical data on motion sickness, which may contribute to the development of relevant fields in science and technology.

Research and Construction Lunar Stereoscopic Visualization System Based on Chang'E Data

NASA Astrophysics Data System (ADS)

Gao, Xingye; Zeng, Xingguo; Zhang, Guihua; Zuo, Wei; Li, ChunLai

2017-04-01

With lunar exploration activities carried by Chang'E-1, Chang'E-2 and Chang'E-3 lunar probe, a large amount of lunar data has been obtained, including topographical and image data covering the whole moon, as well as the panoramic image data of the spot close to the landing point of Chang'E-3. In this paper, we constructed immersive virtual moon system based on acquired lunar exploration data by using advanced stereoscopic visualization technology, which will help scholars to carry out research on lunar topography, assist the further exploration of lunar science, and implement the facilitation of lunar science outreach to the public. In this paper, we focus on the building of lunar stereoscopic visualization system with the combination of software and hardware by using binocular stereoscopic display technology, real-time rendering algorithm for massive terrain data, and building virtual scene technology based on panorama, to achieve an immersive virtual tour of the whole moon and local moonscape of Chang'E-3 landing point.

A stereoscopic system for viewing the temporal evolution of brain activity clusters in response to linguistic stimuli

NASA Astrophysics Data System (ADS)

Forbes, Angus; Villegas, Javier; Almryde, Kyle R.; Plante, Elena

2014-03-01

In this paper, we present a novel application, 3D+Time Brain View, for the stereoscopic visualization of functional Magnetic Resonance Imaging (fMRI) data gathered from participants exposed to unfamiliar spoken languages. An analysis technique based on Independent Component Analysis (ICA) is used to identify statistically significant clusters of brain activity and their changes over time during different testing sessions. That is, our system illustrates the temporal evolution of participants' brain activity as they are introduced to a foreign language through displaying these clusters as they change over time. The raw fMRI data is presented as a stereoscopic pair in an immersive environment utilizing passive stereo rendering. The clusters are presented using a ray casting technique for volume rendering. Our system incorporates the temporal information and the results of the ICA into the stereoscopic 3D rendering, making it easier for domain experts to explore and analyze the data.

Monoscopic versus stereoscopic photography in screening for clinically significant macular edema.

PubMed

Welty, Christopher J; Agarwal, Anita; Merin, Lawrence M; Chomsky, Amy

2006-01-01

The purpose of the study was to determine whether monoscopic photography could serve as an accurate tool when used to screen for clinically significant macular edema. In a masked randomized fashion, two readers evaluated monoscopic and stereoscopic retinal photographs of 100 eyes. The photographs were evaluated first individually for probable clinically significant macular edema based on the Early Treatment Diabetic Retinopathy Study criteria and then as stereoscopic pairs. Graders were evaluated for sensitivity and specificity individually and in combination. Individually, reader one had a sensitivity of 0.93 and a specificity of 0.77, and reader two had a sensitivity of 0.88 and a specificity of 0.94. In combination, the readers had a sensitivity of 0.91 and a specificity of 0.86. They correlated on 0.76 of the stereoscopic readings and 0.92 of the monoscopic readings. These results indicate that the use of monoscopic retinal photography may be an accurate screening tool for clinically significant macular edema.

Stereoscopic depth perception varies with hues

NASA Astrophysics Data System (ADS)

Chen, Zaiqing; Shi, Junsheng; Tai, Yonghang; Yun, Lijun

2012-09-01

The contribution of color information to stereopsis is controversial, and whether the stereoscopic depth perception varies with chromaticity is ambiguous. This study examined the changes in depth perception caused by hue variations. Based on the fact that a greater disparity range indicates more efficient stereoscopic perception, the effect of hue variations on depth perception was evaluated through the disparity range with random-dot stereogram stimuli. The disparity range was obtained by constant-stimulus method for eight chromaticity points sampled from the CIE 1931 chromaticity diagram. Eight sample points include four main color hues: red, yellow, green, and blue at two levels of chroma. The results show that the disparity range for the yellow hue is greater than the red hue, the latter being greater than the blue hue and the disparity range for green hue is smallest. We conclude that the perceived depth is not the same for different hues for a given size of disparity. We suggest that the stereoscopic depth perception can vary with chromaticity.

Usability of stereoscopic view in teleoperation

NASA Astrophysics Data System (ADS)

Boonsuk, Wutthigrai

2015-03-01

Recently, there are tremendous growths in the area of 3D stereoscopic visualization. The 3D stereoscopic visualization technology has been used in a growing number of consumer products such as the 3D televisions and the 3D glasses for gaming systems. This technology refers to the idea that human brain develops depth of perception by retrieving information from the two eyes. Our brain combines the left and right images on the retinas and extracts depth information. Therefore, viewing two video images taken at slightly distance apart as shown in Figure 1 can create illusion of depth [8]. Proponents of this technology argue that the stereo view of 3D visualization increases user immersion and performance as more information is gained through the 3D vision as compare to the 2D view. However, it is still uncertain if additional information gained from the 3D stereoscopic visualization can actually improve user performance in real world situations such as in the case of teleoperation.

Perfect 3-D movies and stereoscopic movies on TV and projection screens: an appraisement

NASA Astrophysics Data System (ADS)

Klein, Susanne; Dultz, Wolfgang

1990-09-01

Since the invention of stereoscopy (WHEATSTONE 1838) reasons for and against 3-dimensional images have occupied the literature, but there has never been much doubt about the preference of autostereoscopic systems showing a scene which is 3-dimensional and true to life from all sides (perfect 3-dimensional image, HESSE 1939), especially since most stereoscopic movies of the past show serious imperfections with respect to image quality and technical operation. Leave aside that no convincing perfect 3D-TV-system is in sight, there are properties f the stereoscopic movie which are advantageous to certain representations on TV and important for the 3-dimensional motion picture. In this paper we investigate the influence of apparent motions of 3-dimensional images and classify the different projection systems with respect to presence and absence of these spectacular illusions. Apparent motions bring dramatic effects into stereoscopic movies which cannot be created with perfect 3-dimensional systems. In this study we describe their applications and limits for television.

Stereoscopic wide field of view imaging system

NASA Technical Reports Server (NTRS)

Prechtl, Eric F. (Inventor); Sedwick, Raymond J. (Inventor); Jonas, Eric M. (Inventor)

2011-01-01

A stereoscopic imaging system incorporates a plurality of imaging devices or cameras to generate a high resolution, wide field of view image database from which images can be combined in real time to provide wide field of view or panoramic or omni-directional still or video images.

Evaluation of stereoscopic medical video content on an autostereoscopic display for undergraduate medical education

NASA Astrophysics Data System (ADS)

Ilgner, Justus F. R.; Kawai, Takashi; Shibata, Takashi; Yamazoe, Takashi; Westhofen, Martin

2006-02-01

Introduction: An increasing number of surgical procedures are performed in a microsurgical and minimally-invasive fashion. However, the performance of surgery, its possibilities and limitations become difficult to teach. Stereoscopic video has evolved from a complex production process and expensive hardware towards rapid editing of video streams with standard and HDTV resolution which can be displayed on portable equipment. This study evaluates the usefulness of stereoscopic video in teaching undergraduate medical students. Material and methods: From an earlier study we chose two clips each of three different microsurgical operations (tympanoplasty type III of the ear, endonasal operation of the paranasal sinuses and laser chordectomy for carcinoma of the larynx). This material was added by 23 clips of a cochlear implantation, which was specifically edited for a portable computer with an autostereoscopic display (PC-RD1-3D, SHARP Corp., Japan). The recording and synchronization of left and right image was performed at the University Hospital Aachen. The footage was edited stereoscopically at the Waseda University by means of our original software for non-linear editing of stereoscopic 3-D movies. Then the material was converted into the streaming 3-D video format. The purpose of the conversion was to present the video clips by a file type that does not depend on a television signal such as PAL or NTSC. 25 4th year medical students who participated in the general ENT course at Aachen University Hospital were asked to estimate depth clues within the six video clips plus cochlear implantation clips. Another 25 4th year students who were shown the material monoscopically on a conventional laptop served as control. Results: All participants noted that the additional depth information helped with understanding the relation of anatomical structures, even though none had hands-on experience with Ear, Nose and Throat operations before or during the course. The monoscopic group generally estimated resection depth to much lesser values than in reality. Although this was the case with some participants in the stereoscopic group, too, the estimation of depth features reflected the enhanced depth impression provided by stereoscopy. Conclusion: Following first implementation of stereoscopic video teaching, medical students who are inexperienced with ENT surgical procedures are able to reproduce depth information and therefore anatomically complex structures to a greater extent following stereoscopic video teaching. Besides extending video teaching to junior doctors, the next evaluation step will address its effect on the learning curve during the surgical training program.

Disparity profiles in 3DV applications: overcoming the issue of heterogeneous viewing conditions in stereoscopic delivery

NASA Astrophysics Data System (ADS)

Boisson, Guillaume; Chamaret, Christel

2012-03-01

More and more numerous 3D movies are released each year. Thanks to the current spread of 3D-TV displays, these 3D Video (3DV) contents are about to enter massively the homes. Yet viewing conditions determine the stereoscopic features achievable for 3DV material. Because the conditions at home - screen size and distance to screen - differ significantly from a theater, 3D Cinema movies need to be repurposed before broadcast and replication on 3D Blu-ray Discs for being fully enjoyed at home. In that paper we tackle that particular issue of how to handle the variety of viewing conditions in stereoscopic contents delivery. To that extend we first investigate what is basically at stake for granting stereoscopic viewers' comfort, through the well-known - and sometimes dispraised - vergence-accommodation conflict. Thereby we define a set of basic rules that can serve as guidelines for 3DV creation. We propose disparity profiles as new requirements for 3DV production and repurposing. Meeting proposed background and foreground constraints prevents from visual fatigue, and occupying the whole depth budget available grants optimal 3D effects. We present an efficient algorithm for automatic disparity-based 3DV retargeting depending on the viewing conditions. Variants are proposed depending on the input format (stereoscopic binocular content or depth-based format) and the level of complexity achievable.

Immersive 3D exposure-based treatment for spider fear: A randomized controlled trial.

PubMed

Minns, Sean; Levihn-Coon, Andrew; Carl, Emily; Smits, Jasper A J; Miller, Wayne; Howard, Don; Papini, Santiago; Quiroz, Simon; Lee-Furman, Eunjung; Telch, Michael; Carlbring, Per; Xanthopoulos, Drew; Powers, Mark B

2018-06-04

Stereoscopic 3D gives the viewer the same shape, size, perspective and depth they would experience viewing the real world and could mimic the perceptual threat cues present in real life. This is the first study to investigate whether an immersive stereoscopic 3D video exposure-based treatment would be effective in reducing fear of spiders. Participants with a fear of spiders (N = 77) watched two psychoeducational videos with facts about spiders and phobias. They were then randomized to a treatment condition that watched a single session of a stereoscopic 3D immersive video exposure-based treatment (six 5-min exposures) delivered through a virtual reality headset or a psychoeducation only control condition that watched a 30-min neutral video (2D documentary) presented on a computer monitor. Assessments of spider fear (Fear of Spiders Questionnaire [FSQ], Behavioral Approach Task [BAT], & subjective ratings of fear) were completed pre- and post-treatment. Consistent with prediction, the stereoscopic 3D video condition outperformed the control condition in reducing fear of spiders showing a large between-group effect size on the FSQ (Cohen's d = 0.85) and a medium between-group effect size on the BAT (Cohen's d = 0.47). This provides initial support for stereoscopic 3D video in treating phobias. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stereoscopy in Static Scientific Imagery in an Informal Education Setting: Does It Matter?

NASA Astrophysics Data System (ADS)

Price, C. Aaron; Lee, H.-S.; Malatesta, K.

2014-12-01

Stereoscopic technology (3D) is rapidly becoming ubiquitous across research, entertainment and informal educational settings. Children of today may grow up never knowing a time when movies, television and video games were not available stereoscopically. Despite this rapid expansion, the field's understanding of the impact of stereoscopic visualizations on learning is rather limited. Much of the excitement of stereoscopic technology could be due to a novelty effect, which will wear off over time. This study controlled for the novelty factor using a variety of techniques. On the floor of an urban science center, 261 children were shown 12 photographs and visualizations of highly spatial scientific objects and scenes. The images were randomly shown in either traditional (2D) format or in stereoscopic format. The children were asked two questions of each image—one about a spatial property of the image and one about a real-world application of that property. At the end of the test, the child was asked to draw from memory the last image they saw. Results showed no overall significant difference in response to the questions associated with 2D or 3D images. However, children who saw the final slide only in 3D drew more complex representations of the slide than those who did not. Results are discussed through the lenses of cognitive load theory and the effect of novelty on engagement.

The effects of 5.1 sound presentations on the perception of stereoscopic imagery in video games

NASA Astrophysics Data System (ADS)

Cullen, Brian; Galperin, Daniel; Collins, Karen; Hogue, Andrew; Kapralos, Bill

2013-03-01

Stereoscopic 3D (S3D) content in games, film and other audio-visual media has been steadily increasing over the past number of years. However, there are still open, fundamental questions regarding its implementation, particularly as it relates to a multi-modal experience that involves sound and haptics. Research has shown that sound has considerable impact on our perception of 2D phenomena, but very little research has considered how sound may influence stereoscopic 3D. Here we present the results of an experiment that examined the effects of 5.1 surround sound (5.1) and stereo loudspeaker setups on depth perception in relation to S3D imagery within a video game environment. Our aim was to answer the question: "can 5.1 surround sound enhance the participant's perception of depth in the stereoscopic field when compared to traditional stereo sound presentations?" In addition, our study examined how the presence or absence of Doppler frequency shift and frequency fall-off audio effects can also influence depth judgment under these conditions. Results suggest that 5.1 surround sound presentations enhance the apparent depth of stereoscopic imagery when compared to stereo presentations. Results also suggest that the addition of audio effects such as Doppler shift and frequency fall-off filters can influence the apparent depth of S3D objects.

Matte painting in stereoscopic synthetic imagery

NASA Astrophysics Data System (ADS)

Eisenmann, Jonathan; Parent, Rick

2010-02-01

While there have been numerous studies concerning human perception in stereoscopic environments, rules of thumb for cinematography in stereoscopy have not yet been well-established. To that aim, we present experiments and results of subject testing in a stereoscopic environment, similar to that of a theater (i.e. large flat screen without head-tracking). In particular we wish to empirically identify thresholds at which different types of backgrounds, referred to in the computer animation industry as matte paintings, can be used while still maintaining the illusion of seamless perspective and depth for a particular scene and camera shot. In monoscopic synthetic imagery, any type of matte painting that maintains proper perspective lines, depth cues, and coherent lighting and textures saves in production costs while still maintaining the illusion of an alternate cinematic reality. However, in stereoscopic synthetic imagery, a 2D matte painting that worked in monoscopy may fail to provide the intended illusion of depth because the viewer has added depth information provided by stereopsis. We intend to observe two stereoscopic perceptual thresholds in this study which will provide practical guidelines indicating when to use each of three types of matte paintings. We ran subject tests in two virtual testing environments, each with varying conditions. Data were collected showing how the choices of the users matched the correct response, and the resulting perceptual threshold patterns are discussed below.

Fusion Prevents the Redundant Signals Effect: Evidence from Stereoscopically Presented Stimuli

ERIC Educational Resources Information Center

Schroter, Hannes; Fiedler, Anja; Miller, Jeff; Ulrich, Rolf

2011-01-01

In a simple reaction time (RT) experiment, visual stimuli were stereoscopically presented either to one eye (single stimulation) or to both eyes (redundant stimulation), with brightness matched for single and redundant stimulations. Redundant stimulation resulted in two separate percepts when noncorresponding retinal areas were stimulated, whereas…

Stereoscopic video analysis of Anopheles gambiae behavior in the field: challenges and opportunities

USDA-ARS?s Scientific Manuscript database

Advances in our ability to localize and track individual swarming mosquitoes in the field via stereoscopic image analysis have enabled us to test long standing ideas about individual male behavior and directly observe coupling. These studies further our fundamental understanding of the reproductive ...

A collaborative virtual reality environment for neurosurgical planning and training.

PubMed

Kockro, Ralf A; Stadie, Axel; Schwandt, Eike; Reisch, Robert; Charalampaki, Cleopatra; Ng, Ivan; Yeo, Tseng Tsai; Hwang, Peter; Serra, Luis; Perneczky, Axel

2007-11-01

We have developed a highly interactive virtual environment that enables collaborative examination of stereoscopic three-dimensional (3-D) medical imaging data for planning, discussing, or teaching neurosurgical approaches and strategies. The system consists of an interactive console with which the user manipulates 3-D data using hand-held and tracked devices within a 3-D virtual workspace and a stereoscopic projection system. The projection system displays the 3-D data on a large screen while the user is working with it. This setup allows users to interact intuitively with complex 3-D data while sharing this information with a larger audience. We have been using this system on a routine clinical basis and during neurosurgical training courses to collaboratively plan and discuss neurosurgical procedures with 3-D reconstructions of patient-specific magnetic resonance and computed tomographic imaging data or with a virtual model of the temporal bone. Working collaboratively with the 3-D information of a large, interactive, stereoscopic projection provides an unambiguous way to analyze and understand the anatomic spatial relationships of different surgical corridors. In our experience, the system creates a unique forum for open and precise discussion of neurosurgical approaches. We believe the system provides a highly effective way to work with 3-D data in a group, and it significantly enhances teaching of neurosurgical anatomy and operative strategies.

Semi-Immersive Virtual Turbine Engine Simulation System

NASA Astrophysics Data System (ADS)

Abidi, Mustufa H.; Al-Ahmari, Abdulrahman M.; Ahmad, Ali; Darmoul, Saber; Ameen, Wadea

2018-05-01

The design and verification of assembly operations is essential for planning product production operations. Recently, virtual prototyping has witnessed tremendous progress, and has reached a stage where current environments enable rich and multi-modal interaction between designers and models through stereoscopic visuals, surround sound, and haptic feedback. The benefits of building and using Virtual Reality (VR) models in assembly process verification are discussed in this paper. In this paper, we present the virtual assembly (VA) of an aircraft turbine engine. The assembly parts and sequences are explained using a virtual reality design system. The system enables stereoscopic visuals, surround sounds, and ample and intuitive interaction with developed models. A special software architecture is suggested to describe the assembly parts and assembly sequence in VR. A collision detection mechanism is employed that provides visual feedback to check the interference between components. The system is tested for virtual prototype and assembly sequencing of a turbine engine. We show that the developed system is comprehensive in terms of VR feedback mechanisms, which include visual, auditory, tactile, as well as force feedback. The system is shown to be effective and efficient for validating the design of assembly, part design, and operations planning.

The Role of Amodal Surface Completion in Stereoscopic Transparency

PubMed Central

Anderson, Barton L.; Schmid, Alexandra C.

2012-01-01

Previous work has shown that the visual system can decompose stereoscopic textures into percepts of inhomogeneous transparency. We investigate whether this form of layered image decomposition is shaped by constraints on amodal surface completion. We report a series of experiments that demonstrate that stereoscopic depth differences are easier to discriminate when the stereo images generate a coherent percept of surface color, than when images require amodally integrating a series of color changes into a coherent surface. Our results provide further evidence for the intimate link between the segmentation processes that occur in conditions of transparency and occlusion, and the interpolation processes involved in the formation of amodally completed surfaces. PMID:23060829

Stereoscopic image production: live, CGI, and integration

NASA Astrophysics Data System (ADS)

Criado, Enrique

2006-02-01

This paper shortly describes part of the experience gathered in more than 10 years of stereoscopic movie production, some of the most common problems found and the solutions, with more or less fortune, we applied to solve those problems. Our work is mainly focused in the entertainment market, theme parks, museums, and other cultural related locations and events. In our movies, we have been forced to develop our own devices to permit correct stereo shooting (stereoscopic rigs) or stereo monitoring (real-time), and to solve problems found with conventional film editing, compositing and postproduction software. Here, we discuss stereo lighting, monitoring, special effects, image integration (using dummies and more), stereo-camera parameters, and other general 3-D movie production aspects.

Preliminary measurements of kinetic dust temperature using stereoscopic particle image velocimetry

NASA Astrophysics Data System (ADS)

Williams, Jeremiah; Thomas, Edward

2004-11-01

A dusty (or complex) plasma is a four-component system composed of ions, electrons, neutral particles and charged microparticles. The presence of the microparticle (i.e., dust) component alters the plasma environment, giving rise to a wide variety of new plasma phenomena. Recently, the Auburn Plasma Sciences Laboratory (PSL) has acquired and installed a stereoscopic PIV (stereo-PIV) diagnostic tool for dusty plasma investigations [Thomas, et. al., Phys. Plasmas, 11, L37 (2004)]. This presentation discusses the use of the stereo-PIV technique for determining the velocity space distribution function of the microparticle component of a dc glow discharge dusty plasma. These distribution functions are then used to make preliminary estimates of the kinetic temperature of the dust component. The data is compared to a simple energy balance model that relates the dust temperature to the electric field and neutral pressure.

UHECR mass composition measurement at Telescope Array via stereoscopic observation

NASA Astrophysics Data System (ADS)

Stroman, Thomas; Telescope Array Collaboration

2015-04-01

The masses of primary ultra-high-energy cosmic-ray (UHECR) nuclei cannot be measured directly on an individual basis, but constraints on the chemical composition can be inferred from the distributions of observable properties. The atmospheric slant depth at which a UHECR-induced extensive air shower reaches its maximum number of particles, Xmax, is particularly sensitive to the mass of the incident nucleus, occurring earlier in the shower's longitudinal development for heavier nuclei at a given energy. The Telescope Array in west-central Utah, the northern hemisphere's largest UHECR detector, is equipped for accurate Xmax and energy measurements via stereoscopic fluorescence observation. Using data from seven years of operation, we will present Xmax distributions at several energies E >10 18 . 2eV , and compare them to distributions predicted by detailed detector simulations under an assortment of assumed UHECR compositions and high-energy hadronic interaction models.

The Impact of Stereoscopic Imagery and Motion on Anatomical Structure Recognition and Visual Attention Performance

ERIC Educational Resources Information Center

Remmele, Martin; Schmidt, Elena; Lingenfelder, Melissa; Martens, Andreas

2018-01-01

Gross anatomy is located in a three-dimensional space. Visualizing aspects of structures in gross anatomy education should aim to provide information that best resembles their original spatial proportions. Stereoscopic three-dimensional imagery might offer possibilities to implement this aim, though some research has revealed potential impairments…

Stereoscopy in Static Scientific Imagery in an Informal Education Setting: Does It Matter?

ERIC Educational Resources Information Center

Price, C. Aaron; Lee, H.-S.; Malatesta, K.

2014-01-01

Stereoscopic technology (3D) is rapidly becoming ubiquitous across research, entertainment and informal educational settings. Children of today may grow up never knowing a time when movies, television and video games were not available stereoscopically. Despite this rapid expansion, the field's understanding of the impact of stereoscopic…

Semi-autonomous wheelchair system using stereoscopic cameras.

PubMed

Nguyen, Jordan S; Nguyen, Thanh H; Nguyen, Hung T

2009-01-01

This paper is concerned with the design and development of a semi-autonomous wheelchair system using stereoscopic cameras to assist hands-free control technologies for severely disabled people. The stereoscopic cameras capture an image from both the left and right cameras, which are then processed with a Sum of Absolute Differences (SAD) correlation algorithm to establish correspondence between image features in the different views of the scene. This is used to produce a stereo disparity image containing information about the depth of objects away from the camera in the image. A geometric projection algorithm is then used to generate a 3-Dimensional (3D) point map, placing pixels of the disparity image in 3D space. This is then converted to a 2-Dimensional (2D) depth map allowing objects in the scene to be viewed and a safe travel path for the wheelchair to be planned and followed based on the user's commands. This assistive technology utilising stereoscopic cameras has the purpose of automated obstacle detection, path planning and following, and collision avoidance during navigation. Experimental results obtained in an indoor environment displayed the effectiveness of this assistive technology.

Is eye damage caused by stereoscopic displays?

NASA Astrophysics Data System (ADS)

Mayer, Udo; Neumann, Markus D.; Kubbat, Wolfgang; Landau, Kurt

2000-05-01

A normal developing child will achieve emmetropia in youth and maintain it. Thereby cornea, lens and axial length of the eye grow astonishingly coordinated. In the last years research has evidenced that this coordinated growing process is a visually controlled closed loop. The mechanism has been studied particularly in animals. It was found that the growth of the axial length of the eyeball is controlled by image focus information from the retina. It was shown that maladjustment can occur by this visually-guided growth control mechanism that result in ametropia. Thereby it has been proven that e.g. short-sightedness is not only caused by heredity, but is acquired under certain visual conditions. It is shown that these conditions are similar to the conditions of viewing stereoscopic displays where the normal accommodation convergence coupling is disjoint. An evaluation is given of the potential of damaging the eyes by viewing stereoscopic displays. Concerning this, different viewing methods for stereoscopic displays are evaluated. Moreover, clues are given how the environment and display conditions shall be set and what users shall be chosen to minimize the risk of eye damages.

Impact of floating windows on the accuracy of depth perception in games

NASA Astrophysics Data System (ADS)

Stanfield, Brodie; Zerebecki, Christopher; Hogue, Andrew; Kapralos, Bill; Collins, Karen

2013-03-01

The floating window technique is commonly employed by stereoscopic 3D filmmakers to reduce the effects of window violations by masking out portions of the screen that contain visual information that doesn't exist in one of the views. Although widely adopted in the film industry, and despite its potential benefits, the technique has not been adopted by video game developers to the same extent possibly because of the lack of understanding of how the floating window can be utilized in such an interactive medium. Here, we describe a quantitative study that investigates how the floating window technique affects users' depth perception in a simple game-like environment. Our goal is to determine how various stereoscopic 3D parameters such as the existence, shape, and size of the floating window affect the user experience and to devise a set of guidelines for game developers wishing to develop stereoscopic 3D content. Providing game designers with quantitative knowledge of how these parameters can affect user experience is invaluable when choosing to design interactive stereoscopic 3D content.

Blur spot limitations in distal endoscope sensors

NASA Astrophysics Data System (ADS)

Yaron, Avi; Shechterman, Mark; Horesh, Nadav

2006-02-01

In years past, the picture quality of electronic video systems was limited by the image sensor. In the present, the resolution of miniature image sensors, as in medical endoscopy, is typically superior to the resolution of the optical system. This "excess resolution" is utilized by Visionsense to create stereoscopic vision. Visionsense has developed a single chip stereoscopic camera that multiplexes the horizontal dimension of the image sensor into two (left and right) images, compensates the blur phenomena, and provides additional depth resolution without sacrificing planar resolution. The camera is based on a dual-pupil imaging objective and an image sensor coated by an array of microlenses (a plenoptic camera). The camera has the advantage of being compact, providing simultaneous acquisition of left and right images, and offering resolution comparable to a dual chip stereoscopic camera with low to medium resolution imaging lenses. A stereoscopic vision system provides an improved 3-dimensional perspective of intra-operative sites that is crucial for advanced minimally invasive surgery and contributes to surgeon performance. An additional advantage of single chip stereo sensors is improvement of tolerance to electronic signal noise.

Comparison of DP3 Signals Evoked by Comfortable 3D Images and 2D Images — an Event-Related Potential Study using an Oddball Task

NASA Astrophysics Data System (ADS)

Ye, Peng; Wu, Xiang; Gao, Dingguo; Liang, Haowen; Wang, Jiahui; Deng, Shaozhi; Xu, Ningsheng; She, Juncong; Chen, Jun

2017-02-01

The horizontal binocular disparity is a critical factor for the visual fatigue induced by watching stereoscopic TVs. Stereoscopic images that possess the disparity within the ‘comfort zones’ and remain still in the depth direction are considered comfortable to the viewers as 2D images. However, the difference in brain activities between processing such comfortable stereoscopic images and 2D images is still less studied. The DP3 (differential P3) signal refers to an event-related potential (ERP) component indicating attentional processes, which is typically evoked by odd target stimuli among standard stimuli in an oddball task. The present study found that the DP3 signal elicited by the comfortable 3D images exhibits the delayed peak latency and enhanced peak amplitude over the anterior and central scalp regions compared to the 2D images. The finding suggests that compared to the processing of the 2D images, more attentional resources are involved in the processing of the stereoscopic images even though they are subjectively comfortable.

AI And Early Vision - Part II

NASA Astrophysics Data System (ADS)

Julesz, Bela

1989-08-01

A quarter of a century ago I introduced two paradigms into psychology which in the intervening years have had a direct impact on the psychobiology of early vision and an indirect one on artificial intelligence (AI or machine vision). The first, the computer-generated random-dot stereogram (RDS) paradigm (Julesz, 1960) at its very inception posed a strategic question both for AI and neurophysiology. The finding that stereoscopic depth perception (stereopsis) is possible without the many enigmatic cues of monocular form recognition - as assumed previously - demonstrated that stereopsis with its basic problem of finding matches between corresponding random aggregates of dots in the left and right visual fields became ripe for modeling. Indeed, the binocular matching problem of stereopsis opened up an entire field of study, eventually leading to the computational models of David Marr (1982) and his coworkers. The fusion of RDS had an even greater impact on neurophysiologists - including Hubel and Wiesel (1962) - who realized that stereopsis must occur at an early stage, and can be studied easier than form perception. This insight recently culminated in the studies by Gian Poggio (1984) who found binocular-disparity - tuned neurons in the input stage to the visual cortex (layer IVB in V1) in the monkey that were selectively triggered by dynamic RDS. Thus the first paradigm led to a strategic insight: that with stereoscopic vision there is no camouflage, and as such was advantageous for our primate ancestors to evolve the cortical machinery of stereoscopic vision to capture camouflaged prey (insects) at a standstill. Amazingly, although stereopsis evolved relatively late in primates, it captured the very input stages of the visual cortex. (For a detailed review, see Julesz, 1986a)

An Affordable Microsurgical Training System for a Beginning Neurosurgeon: How to Realize the Self-Training Laboratory.

PubMed

Chung, Sang-Bong; Ryu, Jiwook; Chung, Yeongu; Lee, Sung Ho; Choi, Seok Keun

2017-09-01

To provide detailed information about how to realize a self-training laboratory with cost-effective microsurgical instruments, especially pertinent for the novice trainee. Our training model is designed to allow the practice of the microsurgery skills in an efficient and cost-effective manner. A used stereoscopic microscope is prepared for microsurgical training. A sufficient working distance for microsurgical practice is obtained by attaching an auxiliary objective lens. The minimum instrument list includes 2 jeweler's forceps, iris scissors, and alligator clips. The iris scissors and alligator clip provide good alternatives to micro-scissors and microvascular clamp. The short time needed to set up the microscope and suture the gauze with micro-forceps makes the training model suitable for daily practice. It takes about 15 minutes to suture 10 neighboring fibers of the gauze with 10-0 nylon; thus, training can be completed more quickly. We have developed an inexpensive and efficient micro-anastomosis training system using a stereoscopic microscope and minimal micro-instruments. Especially useful for novice trainees, this system provides high accessibility for microsurgical training. Copyright © 2017 Elsevier Inc. All rights reserved.

Saliency in VR: How Do People Explore Virtual Environments?

PubMed

Sitzmann, Vincent; Serrano, Ana; Pavel, Amy; Agrawala, Maneesh; Gutierrez, Diego; Masia, Belen; Wetzstein, Gordon

2018-04-01

Understanding how people explore immersive virtual environments is crucial for many applications, such as designing virtual reality (VR) content, developing new compression algorithms, or learning computational models of saliency or visual attention. Whereas a body of recent work has focused on modeling saliency in desktop viewing conditions, VR is very different from these conditions in that viewing behavior is governed by stereoscopic vision and by the complex interaction of head orientation, gaze, and other kinematic constraints. To further our understanding of viewing behavior and saliency in VR, we capture and analyze gaze and head orientation data of 169 users exploring stereoscopic, static omni-directional panoramas, for a total of 1980 head and gaze trajectories for three different viewing conditions. We provide a thorough analysis of our data, which leads to several important insights, such as the existence of a particular fixation bias, which we then use to adapt existing saliency predictors to immersive VR conditions. In addition, we explore other applications of our data and analysis, including automatic alignment of VR video cuts, panorama thumbnails, panorama video synopsis, and saliency-basedcompression.

Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography

PubMed Central

Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S.; Kuo, Anthony N.; Toth, Cynthia A.; Izatt, Joseph A.

2016-01-01

Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

Development of 40-in hybrid hologram screen for auto-stereoscopic video display

NASA Astrophysics Data System (ADS)

Song, Hyun Ho; Nakashima, Y.; Momonoi, Y.; Honda, Toshio

2004-06-01

Usually in auto stereoscopic display, there are two problems. The first problem is that large image display is difficult, and the second problem is that the view zone (which means the zone in which both eyes are put for stereoscopic or 3-D image observation) is very narrow. We have been developing an auto stereoscopic large video display system (over 100 inches diagonal) which a few people can view simultaneously1,2. Usually in displays that are over 100 inches diagonal, an optical video projection system is used. As one of auto stereoscopic display systems the hologram screen has been proposed3,4,5,6. However, if the hologram screen becomes too large, the view zone (corresponding to the reconstructed diffused object) causes color dispersion and color aberration7. We also proposed the additional Fresnel lens attached to the hologram screen. We call the screen a "hybrid hologram screen", (HHS in short). We made the HHS 866mm(H)×433mm(V) (about 40 inch diagonal)8,9,10,11. By using the lens in the reconstruction step, the angle between object light and reference light can be small, compared to without the lens. So, the spread of the view zone by the color dispersion and color aberration becomes small. And also, the virtual image which is reconstructed from the hologram screen can be transformed to a real image (view zone). So, it is not necessary to use a large lens or concave mirror while making a large hologram screen.

Stereopsis and aging.

PubMed

Norman, J Farley; Norman, Hideko F; Craft, Amy E; Walton, Crystal L; Bartholomew, Ashley N; Burton, Cory L; Wiesemann, Elizabeth Y; Crabtree, Charles E

2008-10-01

Three experiments investigated whether and to what extent increases in age affect the functionality of stereopsis. The observers' ages ranged from 18 to 83 years. The overall goal was to challenge the older stereoscopic visual system by utilizing high magnitudes of binocular disparity, ambiguous binocular disparity [cf., Julesz, B., & Chang, J. (1976). Interaction between pools of binocular disparity detectors tuned to different disparities. Biological Cybernetics, 22, 107-119], and by making binocular matching more difficult. In particular, Experiment 1 evaluated observers' abilities to discriminate ordinal depth differences away from the horopter using standing disparities of 6.5-46 min arc. Experiment 2 assessed observers' abilities to discriminate stereoscopic shape using line-element stereograms. The direction (crossed vs. uncrossed) and magnitude of the binocular disparity (13.7 and 51.5 min arc) were manipulated. Binocular matching was made more difficult by varying the orientations of corresponding line elements across the two eyes' views. The purpose of Experiment 3 was to determine whether the aging stereoscopic system can resolve ambiguous binocular disparities in a manner similar to that of younger observers. The results of all experiments demonstrated that older observers' stereoscopic vision is functionally comparable to that of younger observers in many respects. For example, both age groups exhibited a similar ability to discriminate depth and surface shape. The results also showed, however, that age-related differences in stereopsis do exist, and they become most noticeable when the older stereoscopic system is challenged by multiple simultaneous factors.

BOOTSTRAPPING THE CORONAL MAGNETIC FIELD WITH STEREO: UNIPOLAR POTENTIAL FIELD MODELING

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

Aschwanden, Markus J.; Sandman, Anne W., E-mail: aschwanden@lmsal.co

We investigate the recently quantified misalignment of {alpha}{sub mis} {approx} 20{sup 0}-40{sup 0} between the three-dimensional geometry of stereoscopically triangulated coronal loops observed with STEREO/EUVI (in four active regions (ARs)) and theoretical (potential or nonlinear force-free) magnetic field models extrapolated from photospheric magnetograms. We develop an efficient method of bootstrapping the coronal magnetic field by forward fitting a parameterized potential field model to the STEREO-observed loops. The potential field model consists of a number of unipolar magnetic charges that are parameterized by decomposing a photospheric magnetogram from the Michelson Doppler Imager. The forward-fitting method yields a best-fit magnetic field modelmore » with a reduced misalignment of {alpha}{sub PF} {approx} 13{sup 0}-20{sup 0}. We also evaluate stereoscopic measurement errors and find a contribution of {alpha}{sub SE} {approx} 7{sup 0}-12{sup 0}, which constrains the residual misalignment to {alpha}{sub NP} {approx} 11{sup 0}-17{sup 0}, which is likely due to the nonpotentiality of the ARs. The residual misalignment angle, {alpha}{sub NP}, of the potential field due to nonpotentiality is found to correlate with the soft X-ray flux of the AR, which implies a relationship between electric currents and plasma heating.« less

Application of full-scale three-dimensional models in patients with rheumatoid cervical spine.

PubMed

Mizutani, Jun; Matsubara, Takeshi; Fukuoka, Muneyoshi; Tanaka, Nobuhiko; Iguchi, Hirotaka; Furuya, Aiharu; Okamoto, Hideki; Wada, Ikuo; Otsuka, Takanobu

2008-05-01

Full-scale three-dimensional (3D) models offer a useful tool in preoperative planning, allowing full-scale stereoscopic recognition from any direction and distance with tactile feedback. Although skills and implants have progressed with various innovations, rheumatoid cervical spine surgery remains challenging. No previous studies have documented the usefulness of full-scale 3D models in this complicated situation. The present study assessed the utility of full-scale 3D models in rheumatoid cervical spine surgery. Polyurethane or plaster 3D models of 15 full-sized occipitocervical or upper cervical spines were fabricated using rapid prototyping (stereolithography) techniques from 1-mm slices of individual CT data. A comfortable alignment for patients was reproduced from CT data obtained with the patient in a comfortable occipitocervical position. Usefulness of these models was analyzed. Using models as a template, appropriate shape of the plate-rod construct could be created in advance. No troublesome Halo-vests were needed for preoperative adjustment of occipitocervical angle. No patients complained of dysphasia following surgery. Screw entry points and trajectories were simultaneously determined with full-scale dimensions and perspective, proving particularly valuable in cases involving high-riding vertebral artery. Full-scale stereoscopic recognition has never been achieved with any existing imaging modalities. Full-scale 3D models thus appear useful and applicable to all complicated spinal surgeries. The combination of computer-assisted navigation systems and full-scale 3D models appears likely to provide much better surgical results.

How to See Shadows in 3D

ERIC Educational Resources Information Center

Parikesit, Gea O. F.

2014-01-01

Shadows can be found easily everywhere around us, so that we rarely find it interesting to reflect on how they work. In order to raise curiosity among students on the optics of shadows, we can display the shadows in 3D, particularly using a stereoscopic set-up. In this paper we describe the optics of stereoscopic shadows using simple schematic…

Looking White and Middle-Class: Stereoscopic Imagery and Technology in the Early Twentieth-Century United States

ERIC Educational Resources Information Center

Malin, Brenton J.

2007-01-01

This essay explores a series of discourses surrounding the images of the early twentieth-century stereoscope, focusing on Underwood & Underwood of Ottawa, Kansas, and the Keystone View Company, of Meadville, Pennsylvania. By publishing images of particular geographic areas and historical events, as well as compendium volumes that included…

Hurricane structure and wind fields from stereoscopic and infrared satellite observations and radar data

NASA Technical Reports Server (NTRS)

Hasler, A. F.; Morris, K. R.

1986-01-01

Hurricane cloud and precipitation structure have been studied by means of IR and stereoscopic visual satellite data from synchronized scanning GOES-East and -West, in combination with ground-based radar data for Hurricane Frederico and time-composited airborne radar data for Hurricane Allen. It is noted that stereoscopically measured cloudtop height in these hurricanes is not as closely correlated to radar reflectivity at lower levels as it is in intense thunderstorms over land. This and other results obtained imply that satellite precipitation estimation techniques for tropical cyclones that are based on cloudtop measurements will not be accurate with respect to time and place scales that are less than several hours and a few hundred km, respectively.

Measuring sensitivity to viewpoint change with and without stereoscopic cues.

PubMed

Bell, Jason; Dickinson, Edwin; Badcock, David R; Kingdom, Frederick A A

2013-12-04

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

Distortion of depth perception in virtual environments using stereoscopic displays: quantitative assessment and corrective measures

NASA Astrophysics Data System (ADS)

Kleiber, Michael; Winkelholz, Carsten

2008-02-01

The aim of the presented research was to quantify the distortion of depth perception when using stereoscopic displays. The visualization parameters of the used virtual reality system such as perspective, haploscopic separation and width of stereoscopic separation were varied. The experiment was designed to measure distortion in depth perception according to allocentric frames of reference. The results of the experiments indicate that some of the parameters have an antithetic effect which allows to compensate the distortion of depth perception for a range of depths. In contrast to earlier research which reported underestimation of depth perception we found that depth was overestimated when using true projection parameters according to the position of the eyes of the user and display geometry.

Balance and coordination after viewing stereoscopic 3D television

PubMed Central

Read, Jenny C. A.; Simonotto, Jennifer; Bohr, Iwo; Godfrey, Alan; Galna, Brook; Rochester, Lynn; Smulders, Tom V.

2015-01-01

Manufacturers and the media have raised the possibility that viewing stereoscopic 3D television (S3D TV) may cause temporary disruption to balance and visuomotor coordination. We looked for evidence of such effects in a laboratory-based study. Four hundred and thirty-three people aged 4–82 years old carried out tests of balance and coordination before and after viewing an 80 min movie in either conventional 2D or stereoscopic 3D, while wearing two triaxial accelerometers. Accelerometry produced little evidence of any change in body motion associated with S3D TV. We found no evidence that viewing the movie in S3D causes a detectable impairment in balance or in visuomotor coordination. PMID:26587261

Generating Stereoscopic Television Images With One Camera

NASA Technical Reports Server (NTRS)

Coan, Paul P.

1996-01-01

Straightforward technique for generating stereoscopic television images involves use of single television camera translated laterally between left- and right-eye positions. Camera acquires one of images (left- or right-eye image), and video signal from image delayed while camera translated to position where it acquires other image. Length of delay chosen so both images displayed simultaneously or as nearly simultaneously as necessary to obtain stereoscopic effect. Technique amenable to zooming in on small areas within broad scenes. Potential applications include three-dimensional viewing of geological features and meteorological events from spacecraft and aircraft, inspection of workpieces moving along conveyor belts, and aiding ground and water search-and-rescue operations. Also used to generate and display imagery for public education and general information, and possible for medical purposes.

Measurement of the flux of ultra high energy cosmic rays by the stereo technique

NASA Astrophysics Data System (ADS)

High Resolution Fly'S Eye Collaboration; Abbasi, R. U.; Abu-Zayyad, T.; Al-Seady, M.; Allen, M.; Amann, J. F.; Archbold, G.; Belov, K.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Brusova, O. A.; Burt, G. W.; Cannon, C.; Cao, Z.; Deng, W.; Fedorova, Y.; Findlay, J.; Finley, C. B.; Gray, R. C.; Hanlon, W. F.; Hoffman, C. M.; Holzscheiter, M. H.; Hughes, G.; Hüntemeyer, P.; Ivanov, D.; Jones, B. F.; Jui, C. C. H.; Kim, K.; Kirn, M. A.; Loh, E. C.; Maestas, M. M.; Manago, N.; Marek, L. J.; Martens, K.; Matthews, J. A. J.; Matthews, J. N.; Moore, S. A.; O'Neill, A.; Painter, C. A.; Perera, L.; Reil, K.; Riehle, R.; Roberts, M. D.; Rodriguez, D.; Sasaki, M.; Schnetzer, S. R.; Scott, L. M.; Sinnis, G.; Smith, J. D.; Snow, R.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Thomas, J. R.; Thomas, S. B.; Thomson, G. B.; Tupa, D.; Wiencke, L. R.; Zech, A.; Zhang, B. K.; Zhang, X.; Zhang, Y.; High Resolution Fly's Eye Collaboration

2009-08-01

The High Resolution Fly’s Eye (HiRes) experiment has measured the flux of ultrahigh energy cosmic rays using the stereoscopic air fluorescence technique. The HiRes experiment consists of two detectors that observe cosmic ray showers via the fluorescence light they emit. HiRes data can be analyzed in monocular mode, where each detector is treated separately, or in stereoscopic mode where they are considered together. Using the monocular mode the HiRes collaboration measured the cosmic ray spectrum and made the first observation of the Greisen-Zatsepin-Kuzmin cutoff. In this paper we present the cosmic ray spectrum measured by the stereoscopic technique. Good agreement is found with the monocular spectrum in all details.

Intubation simulation with a cross-sectional visual guidance.

PubMed

Rhee, Chi-Hyoung; Kang, Chul Won; Lee, Chang Ha

2013-01-01

We present an intubation simulation with deformable objects and a cross-sectional visual guidance using a general haptic device. Our method deforms the tube model when it collides with the human model. Mass-Spring model with the Euler integration is used for the tube deformation. For the trainee's more effective understanding of the intubation process, we provide a cross-sectional view of the oral cavity and the tube. Our system also applies a stereoscopic rendering to improve the depth perception and the reality of the simulation.

Reconnaissance mapping from aerial photographs

NASA Technical Reports Server (NTRS)

Weeden, H. A.; Bolling, N. B. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Engineering soil and geology maps were successfully made from Pennsylvania aerial photographs taken at scales from 1:4,800 to 1:60,000. The procedure involved a detailed study of a stereoscopic model while evaluating landform, drainage, erosion, color or gray tones, tone and texture patterns, vegetation, and cultural or land use patterns.

Teaching Anatomy and Physiology Using Computer-Based, Stereoscopic Images

ERIC Educational Resources Information Center

Perry, Jamie; Kuehn, David; Langlois, Rick

2007-01-01

Learning real three-dimensional (3D) anatomy for the first time can be challenging. Two-dimensional drawings and plastic models tend to over-simplify the complexity of anatomy. The approach described uses stereoscopy to create 3D images of the process of cadaver dissection and to demonstrate the underlying anatomy related to the speech mechanisms.…

Training Performance of Laparoscopic Surgery in Two- and Three-Dimensional Displays.

PubMed

Lin, Chiuhsiang Joe; Cheng, Chih-Feng; Chen, Hung-Jen; Wu, Kuan-Ying

2017-04-01

This research investigated differences in the effects of a state-of-art stereoscopic 3-dimensional (3D) display and a traditional 2-dimensional (2D) display in simulated laparoscopic surgery over a longer duration than in previous publications and studied the learning effects of the 2 display systems on novices. A randomized experiment with 2 factors, image dimensions and image sequence, was conducted to investigate differences in the mean movement time, the mean error frequency, NASA-TLX cognitive workload, and visual fatigue in pegboard and circle-tracing tasks. The stereoscopic 3D display had advantages in mean movement time ( P < .001 and P = .002) and mean error frequency ( P = .010 and P = .008) in both the tasks. There were no significant differences in the objective visual fatigue ( P = .729 and P = .422) and in the NASA-TLX ( P = .605 and P = .937) cognitive workload between the 3D and the 2D displays on both the tasks. For the learning effect, participants who used the stereoscopic 3D display first had shorter mean movement time in the 2D display environment on both the pegboard ( P = .011) and the circle-tracing ( P = .017) tasks. The results of this research suggest that a stereoscopic system would not result in higher objective visual fatigue and cognitive workload than a 2D system, and it might reduce the performance time and increase the precision of surgical operations. In addition, learning efficiency of the stereoscopic system on the novices in this study demonstrated its value for training and education in laparoscopic surgery.

The effects of video game experience and active stereoscopy on performance in combat identification tasks.

PubMed

Keebler, Joseph R; Jentsch, Florian; Schuster, David

2014-12-01

We investigated the effects of active stereoscopic simulation-based training and individual differences in video game experience on multiple indices of combat identification (CID) performance. Fratricide is a major problem in combat operations involving military vehicles. In this research, we aimed to evaluate the effects of training on CID performance in order to reduce fratricide errors. Individuals were trained on 12 combat vehicles in a simulation, which were presented via either a non-stereoscopic or active stereoscopic display using NVIDIA's GeForce shutter glass technology. Self-report was used to assess video game experience, leading to four between-subjects groups: high video game experience with stereoscopy, low video game experience with stereoscopy, high video game experience without stereoscopy, and low video game experience without stereoscopy. We then tested participants on their memory of each vehicle's alliance and name across multiple measures, including photographs and videos. There was a main effect for both video game experience and stereoscopy across many of the dependent measures. Further, we found interactions between video game experience and stereoscopic training, such that those individuals with high video game experience in the non-stereoscopic group had the highest performance outcomes in the sample on multiple dependent measures. This study suggests that individual differences in video game experience may be predictive of enhanced performance in CID tasks. Selection based on video game experience in CID tasks may be a useful strategy for future military training. Future research should investigate the generalizability of these effects, such as identification through unmanned vehicle sensors.

What is 3D good for? A review of human performance on stereoscopic 3D displays

NASA Astrophysics Data System (ADS)

McIntire, John P.; Havig, Paul R.; Geiselman, Eric E.

2012-06-01

This work reviews the human factors-related literature on the task performance implications of stereoscopic 3D displays, in order to point out the specific performance benefits (or lack thereof) one might reasonably expect to observe when utilizing these displays. What exactly is 3D good for? Relative to traditional 2D displays, stereoscopic displays have been shown to enhance performance on a variety of depth-related tasks. These tasks include judging absolute and relative distances, finding and identifying objects (by breaking camouflage and eliciting perceptual "pop-out"), performing spatial manipulations of objects (object positioning, orienting, and tracking), and navigating. More cognitively, stereoscopic displays can improve the spatial understanding of 3D scenes or objects, improve memory/recall of scenes or objects, and improve learning of spatial relationships and environments. However, for tasks that are relatively simple, that do not strictly require depth information for good performance, where other strong cues to depth can be utilized, or for depth tasks that lie outside the effective viewing volume of the display, the purported performance benefits of 3D may be small or altogether absent. Stereoscopic 3D displays come with a host of unique human factors problems including the simulator-sickness-type symptoms of eyestrain, headache, fatigue, disorientation, nausea, and malaise, which appear to effect large numbers of viewers (perhaps as many as 25% to 50% of the general population). Thus, 3D technology should be wielded delicately and applied carefully; and perhaps used only as is necessary to ensure good performance.

Evaluating a Novel 3D Stereoscopic Visual Display for Transanal Endoscopic Surgery: A Randomized Controlled Crossover Study.

PubMed

Di Marco, Aimee N; Jeyakumar, Jenifa; Pratt, Philip J; Yang, Guang-Zhong; Darzi, Ara W

2016-01-01

To compare surgical performance with transanal endoscopic surgery (TES) using a novel 3-dimensional (3D) stereoscopic viewer against the current modalities of a 3D stereoendoscope, 3D, and 2-dimensional (2D) high-definition monitors. TES is accepted as the primary treatment for selected rectal tumors. Current TES systems offer a 2D monitor, or 3D image, viewed directly via a stereoendoscope, necessitating an uncomfortable operating position. To address this and provide a platform for future image augmentation, a 3D stereoscopic display was created. Forty participants, of mixed experience level, completed a simulated TES task using 4 visual displays (novel stereoscopic viewer and currently utilized stereoendoscope, 3D, and 2D high-definition monitors) in a randomly allocated order. Primary outcome measures were: time taken, path length, and accuracy. Secondary outcomes were: task workload and participant questionnaire results. Median time taken and path length were significantly shorter for the novel viewer versus 2D and 3D, and not significantly different to the traditional stereoendoscope. Significant differences were found in accuracy, task workload, and questionnaire assessment in favor of the novel viewer, as compared to all 3 modalities. This novel 3D stereoscopic viewer allows surgical performance in TES equivalent to that achieved using the current stereoendoscope and superior to standard 2D and 3D displays, but with lower physical and mental demands for the surgeon. Participants expressed a preference for this system, ranking it more highly on a questionnaire. Clinical translation of this work has begun with the novel viewer being used in 5 TES patients.

Tissue feature-based intra-fractional motion tracking for stereoscopic x-ray image guided radiotherapy

NASA Astrophysics Data System (ADS)

Xie, Yaoqin; Xing, Lei; Gu, Jia; Liu, Wu

2013-06-01

Real-time knowledge of tumor position during radiation therapy is essential to overcome the adverse effect of intra-fractional organ motion. The goal of this work is to develop a tumor tracking strategy by effectively utilizing the inherent image features of stereoscopic x-ray images acquired during dose delivery. In stereoscopic x-ray image guided radiation delivery, two orthogonal x-ray images are acquired either simultaneously or sequentially. The essence of markerless tumor tracking is the reliable identification of inherent points with distinct tissue features on each projection image and their association between two images. The identification of the feature points on a planar x-ray image is realized by searching for points with high intensity gradient. The feature points are associated by using the scale invariance features transform descriptor. The performance of the proposed technique is evaluated by using images of a motion phantom and four archived clinical cases acquired using either a CyberKnife equipped with a stereoscopic x-ray imaging system, or a LINAC equipped with an onboard kV imager and an electronic portal imaging device. In the phantom study, the results obtained using the proposed method agree with the measurements to within 2 mm in all three directions. In the clinical study, the mean error is 0.48 ± 0.46 mm for four patient data with 144 sequential images. In this work, a tissue feature-based tracking method for stereoscopic x-ray image guided radiation therapy is developed. The technique avoids the invasive procedure of fiducial implantation and may greatly facilitate the clinical workflow.

Organizational Learning Goes Virtual?: A Study of Employees' Learning Achievement in Stereoscopic 3D Virtual Reality

ERIC Educational Resources Information Center

Lau, Kung Wong

2015-01-01

Purpose: This study aims to deepen understanding of the use of stereoscopic 3D technology (stereo3D) in facilitating organizational learning. The emergence of advanced virtual technologies, in particular to the stereo3D virtual reality, has fundamentally changed the ways in which organizations train their employees. However, in academic or…

Comparing Short- and Long-Term Learning Effects between Stereoscopic and Two-Dimensional Film at a Planetarium

ERIC Educational Resources Information Center

Price, C. Aaron; Lee, Hee-Sun; Subbarao, Mark; Kasal, Evan; Aguileara, Julieta

2015-01-01

Science centers such as museums and planetariums have used stereoscopic ("three-dimensional") films to draw interest from and educate their visitors for decades. Despite the fact that most adults who are finished with their formal education get their science knowledge from such free-choice learning settings very little is known about the…

Teaching with Stereoscopic Video: Opportunities and Challenges

NASA Astrophysics Data System (ADS)

Variano, Evan

2017-11-01

I will present my work on creating stereoscopic videos for fluid pedagogy. I discuss a variety of workflows for content creation and a variety of platforms for content delivery. I review the qualitative lessons learned when teaching with this material, and discuss outlook for the future. This work was partially supported by the NSF award ENG-1604026 and the UC Berkeley Student Technology Fund.

Single-channel stereoscopic ophthalmology microscope based on TRD

NASA Astrophysics Data System (ADS)

Radfar, Edalat; Park, Jihoon; Lee, Sangyeob; Ha, Myungjin; Yu, Sungkon; Jang, Seulki; Jung, Byungjo

2016-03-01

A stereoscopic imaging modality was developed for the application of ophthalmology surgical microscopes. A previous study has already introduced a single-channel stereoscopic video imaging modality based on a transparent rotating deflector (SSVIM-TRD), in which two different view angles, image disparity, are generated by imaging through a transparent rotating deflector (TRD) mounted on a stepping motor and is placed in a lens system. In this case, the image disparity is a function of the refractive index and the rotation angle of TRD. Real-time single-channel stereoscopic ophthalmology microscope (SSOM) based on the TRD is improved by real-time controlling and programming, imaging speed, and illumination method. Image quality assessments were performed to investigate images quality and stability during the TRD operation. Results presented little significant difference in image quality in terms of stability of structural similarity (SSIM). A subjective analysis was performed with 15 blinded observers to evaluate the depth perception improvement and presented significant improvement in the depth perception capability. Along with all evaluation results, preliminary results of rabbit eye imaging presented that the SSOM could be utilized as an ophthalmic operating microscopes to overcome some of the limitations of conventional ones.

3D moviemap and a 3D panorama

NASA Astrophysics Data System (ADS)

Naimark, Michael

1997-05-01

Two immersive virtual environments produced as art installations investigate 'sense of place' in different but complimentary ways. One is a stereoscopic moviemap, the other a stereoscopic panorama. Moviemaps are interactive systems which allow 'travel' along pre-recorded routes with some control over speed and direction. Panoramas are 360 degree visual representations dating back to the late 18th century but which have recently experienced renewed interest due to 'virtual reality' systems. Moviemaps allow 'moving around' while panoramas allow 'looking around,' but to date there has been little or no attempt to produce either in stereo from camera-based material. 'See Banff stereoscopic moviemap about landscape, tourism, and growth in the Canadian Rocky Mountains. It was filmed with twin 16 mm cameras and displayed as a single-user experience housed in a cabinet resembling a century-old kinetoscope, with a crank on the side for 'moving through' the material. 'Be Now Here (Welcome to the Neighborhood)' (1995-6) is a stereoscopic panorama filmed in public gathering places around the world, based upon the UNESCO World Heritage 'In Danger' list. It was filmed with twin 35 mm motion picture cameras on a rotating tripod and displayed using a synchronized rotating floor.

Stereoscopic medical imaging collaboration system

NASA Astrophysics Data System (ADS)

Okuyama, Fumio; Hirano, Takenori; Nakabayasi, Yuusuke; Minoura, Hirohito; Tsuruoka, Shinji

2007-02-01

The computerization of the clinical record and the realization of the multimedia have brought improvement of the medical service in medical facilities. It is very important for the patients to obtain comprehensible informed consent. Therefore, the doctor should plainly explain the purpose and the content of the diagnoses and treatments for the patient. We propose and design a Telemedicine Imaging Collaboration System which presents a three dimensional medical image as X-ray CT, MRI with stereoscopic image by using virtual common information space and operating the image from a remote location. This system is composed of two personal computers, two 15 inches stereoscopic parallax barrier type LCD display (LL-151D, Sharp), one 1Gbps router and 1000base LAN cables. The software is composed of a DICOM format data transfer program, an operation program of the images, the communication program between two personal computers and a real time rendering program. Two identical images of 512×768 pixcels are displayed on two stereoscopic LCD display, and both images show an expansion, reduction by mouse operation. This system can offer a comprehensible three-dimensional image of the diseased part. Therefore, the doctor and the patient can easily understand it, depending on their needs.

Toward a 3D video format for auto-stereoscopic displays

NASA Astrophysics Data System (ADS)

Vetro, Anthony; Yea, Sehoon; Smolic, Aljoscha

2008-08-01

There has been increased momentum recently in the production of 3D content for cinema applications; for the most part, this has been limited to stereo content. There are also a variety of display technologies on the market that support 3DTV, each offering a different viewing experience and having different input requirements. More specifically, stereoscopic displays support stereo content and require glasses, while auto-stereoscopic displays avoid the need for glasses by rendering view-dependent stereo pairs for a multitude of viewing angles. To realize high quality auto-stereoscopic displays, multiple views of the video must either be provided as input to the display, or these views must be created locally at the display. The former approach has difficulties in that the production environment is typically limited to stereo, and transmission bandwidth for a large number of views is not likely to be available. This paper discusses an emerging 3D data format that enables the latter approach to be realized. A new framework for efficiently representing a 3D scene and enabling the reconstruction of an arbitrarily large number of views prior to rendering is introduced. Several design challenges are also highlighted through experimental results.

Trade-offs arising from mixture of color cueing and monocular, binoptic, and stereoscopic cueing information for simulated rotorcraft flight

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Williams, Steven P.

1993-01-01

To provide stereopsis, binocular helmet-mounted display (HMD) systems must trade some of the total field of view available from their two monocular fields to obtain a partial overlap region. The visual field then provides a mixture of cues, with monocular regions on both peripheries and a binoptic (the same image in both eyes) region or, if lateral disparity is introduced to produce two images, a stereoscopic region in the overlapped center. This paper reports on in-simulator assessment of the trade-offs arising from the mixture of color cueing and monocular, binoptic, and stereoscopic cueing information in peripheral monitoring displays as utilized in HMD systems. The accompanying effect of stereoscopic cueing in the tracking information in the central region of the display is also assessed. The pilot's task for the study was to fly at a prescribed height above an undulating pathway in the sky while monitoring a dynamic bar chart displayed in the periphery of their field of view. Control of the simulated rotorcraft was limited to the longitudinal and vertical degrees of freedom to ensure the lateral separation of the viewing conditions of the concurrent tasks.

Viewpoint Dependent Imaging: An Interactive Stereoscopic Display

NASA Astrophysics Data System (ADS)

Fisher, Scott

1983-04-01

Design and implementation of a viewpoint Dependent imaging system is described. The resultant display is an interactive, lifesize, stereoscopic image. that becomes a window into a three dimensional visual environment. As the user physically changes his viewpoint of the represented data in relation to the display surface, the image is continuously updated. The changing viewpoints are retrieved from a comprehensive, stereoscopic image array stored on computer controlled, optical videodisc and fluidly presented. in coordination with the viewer's, movements as detected by a body-tracking device. This imaging system is an attempt to more closely represent an observers interactive perceptual experience of the visual world by presenting sensory information cues not offered by traditional media technologies: binocular parallax, motion parallax, and motion perspective. Unlike holographic imaging, this display requires, relatively low bandwidth.

Accommodation training in foreign workers.

PubMed

Takada, Masumi; Miyao, Masaru; Matsuura, Yasuyuki; Takada, Hiroki

2013-01-01

By relaxing the contracted focus-adjustment muscles around the eyeball, known as the ciliary and extraocular muscles, the degree of pseudomyopia can be reduced. This understanding has led to accommodation training in which a visual target is presented in stereoscopic video clips. However, it has been pointed out that motion sickness can be induced by viewing stereoscopic video clips. In Measurement 1 of the present study, we verified whether the new 3D technology reduced the severity of motion sickness in accordance with stabilometry. We then evaluated the short-term effects of accommodation training using new stereoscopic video clips on foreign workers (11 females) suffering from eye fatigue in Measurement 2. The foreign workers were trained for three days. As a result, visual acuity was statistically improved by continuous accommodation training, which will help promote ciliary muscle stretching.

An MR-compatible stereoscopic in-room 3D display for MR-guided interventions.

PubMed

Brunner, Alexander; Groebner, Jens; Umathum, Reiner; Maier, Florian; Semmler, Wolfhard; Bock, Michael

2014-08-01

A commercial three-dimensional (3D) monitor was modified for use inside the scanner room to provide stereoscopic real-time visualization during magnetic resonance (MR)-guided interventions, and tested in a catheter-tracking phantom experiment at 1.5 T. Brightness, uniformity, radio frequency (RF) emissions and MR image interferences were measured. Due to modifications, the center luminance of the 3D monitor was reduced by 14%, and the addition of a Faraday shield further reduced the remaining luminance by 31%. RF emissions could be effectively shielded; only a minor signal-to-noise ratio (SNR) decrease of 4.6% was observed during imaging. During the tracking experiment, the 3D orientation of the catheter and vessel structures in the phantom could be visualized stereoscopically.

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.

3D gaze tracking system for NVidia 3D Vision®.

PubMed

Wibirama, Sunu; Hamamoto, Kazuhiko

2013-01-01

Inappropriate parallax setting in stereoscopic content generally causes visual fatigue and visual discomfort. To optimize three dimensional (3D) effects in stereoscopic content by taking into account health issue, understanding how user gazes at 3D direction in virtual space is currently an important research topic. In this paper, we report the study of developing a novel 3D gaze tracking system for Nvidia 3D Vision(®) to be used in desktop stereoscopic display. We suggest an optimized geometric method to accurately measure the position of virtual 3D object. Our experimental result shows that the proposed system achieved better accuracy compared to conventional geometric method by average errors 0.83 cm, 0.87 cm, and 1.06 cm in X, Y, and Z dimensions, respectively.

A novel 360-degree shape measurement using a simple setup with two mirrors and a laser MEMS scanner

NASA Astrophysics Data System (ADS)

Jin, Rui; Zhou, Xiang; Yang, Tao; Li, Dong; Wang, Chao

2017-09-01

There is no denying that 360-degree shape measurement technology plays an important role in the field of threedimensional optical metrology. Traditional optical 360-degree shape measurement methods are mainly two kinds: the first kind, by placing multiple scanners to achieve 360-degree measurements; the second kind, through the high-precision rotating device to get 360-degree shape model. The former increases the number of scanners and costly, while the latter using rotating devices lead to time consuming. This paper presents a low cost and fast optical 360-degree shape measurement method, which possesses the advantages of full static, fast and low cost. The measuring system consists of two mirrors with a certain angle, a laser projection system, a stereoscopic calibration block, and two cameras. And most of all, laser MEMS scanner can achieve precise movement of laser stripes without any movement mechanism, improving the measurement accuracy and efficiency. What's more, a novel stereo calibration technology presented in this paper can achieve point clouds data registration, and then get the 360-degree model of objects. A stereoscopic calibration block with special coded patterns on six sides is used in this novel stereo calibration method. Through this novel stereo calibration technology we can quickly get the 360-degree models of objects.

Lie group model neuromorphic geometric engine for real-time terrain reconstruction from stereoscopic aerial photos

NASA Astrophysics Data System (ADS)

Tsao, Thomas R.; Tsao, Doris

1997-04-01

In the 1980's, neurobiologist suggested a simple mechanism in primate visual cortex for maintaining a stable and invariant representation of a moving object. The receptive field of visual neurons has real-time transforms in response to motion, to maintain a stable representation. When the visual stimulus is changed due to motion, the geometric transform of the stimulus triggers a dual transform of the receptive field. This dual transform in the receptive fields compensates geometric variation in the stimulus. This process can be modelled using a Lie group method. The massive array of affine parameter sensing circuits will function as a smart sensor tightly coupled to the passive imaging sensor (retina). Neural geometric engine is a neuromorphic computing device simulating our Lie group model of spatial perception of primate's primal visual cortex. We have developed the computer simulation and experimented on realistic and synthetic image data, and performed a preliminary research of using analog VLSI technology for implementation of the neural geometric engine. We have benchmark tested on DMA's terrain data with their result and have built an analog integrated circuit to verify the computational structure of the engine. When fully implemented on ANALOG VLSI chip, we will be able to accurately reconstruct a 3D terrain surface in real-time from stereoscopic imagery.

Saliency Detection of Stereoscopic 3D Images with Application to Visual Discomfort Prediction

NASA Astrophysics Data System (ADS)

Li, Hong; Luo, Ting; Xu, Haiyong

2017-06-01

Visual saliency detection is potentially useful for a wide range of applications in image processing and computer vision fields. This paper proposes a novel bottom-up saliency detection approach for stereoscopic 3D (S3D) images based on regional covariance matrix. As for S3D saliency detection, besides the traditional 2D low-level visual features, additional 3D depth features should also be considered. However, only limited efforts have been made to investigate how different features (e.g. 2D and 3D features) contribute to the overall saliency of S3D images. The main contribution of this paper is that we introduce a nonlinear feature integration descriptor, i.e., regional covariance matrix, to fuse both 2D and 3D features for S3D saliency detection. The regional covariance matrix is shown to be effective for nonlinear feature integration by modelling the inter-correlation of different feature dimensions. Experimental results demonstrate that the proposed approach outperforms several existing relevant models including 2D extended and pure 3D saliency models. In addition, we also experimentally verified that the proposed S3D saliency map can significantly improve the prediction accuracy of experienced visual discomfort when viewing S3D images.

Fisheye-Based Method for GPS Localization Improvement in Unknown Semi-Obstructed Areas

PubMed Central

Moreau, Julien; Ambellouis, Sébastien; Ruichek, Yassine

2017-01-01

A precise GNSS (Global Navigation Satellite System) localization is vital for autonomous road vehicles, especially in cluttered or urban environments where satellites are occluded, preventing accurate positioning. We propose to fuse GPS (Global Positioning System) data with fisheye stereovision to face this problem independently to additional data, possibly outdated, unavailable, and needing correlation with reality. Our stereoscope is sky-facing with 360° × 180° fisheye cameras to observe surrounding obstacles. We propose a 3D modelling and plane extraction through following steps: stereoscope self-calibration for decalibration robustness, stereo matching considering neighbours epipolar curves to compute 3D, and robust plane fitting based on generated cartography and Hough transform. We use these 3D data with GPS raw data to estimate NLOS (Non Line Of Sight) reflected signals pseudorange delay. We exploit extracted planes to build a visibility mask for NLOS detection. A simplified 3D canyon model allows to compute reflections pseudorange delays. In the end, GPS positioning is computed considering corrected pseudoranges. With experimentations on real fixed scenes, we show generated 3D models reaching metric accuracy and improvement of horizontal GPS positioning accuracy by more than 50%. The proposed procedure is effective, and the proposed NLOS detection outperforms CN0-based methods (Carrier-to-receiver Noise density). PMID:28106746

3D Displays for Battle Management

DTIC Science & Technology

1990-04-01

cinematography industry, were found to be inadequate for providing comfortable stereoscopic out-the-window terrain scenes, when viewed from a 19-inch...JStereoscoDic Projection GeomietrvL Existing stereoscopic drawing / fechniques, which have roots in t cinematography industry, were , found to be...categories. By calibrating our CRT monitors to known color standards, we are able to produce the measured hues on the display screen. 5.2 COMPLEXITY

The Influence of Manifest Strabismus and Stereoscopic Vision on Non-Verbal Abilities of Visually Impaired Children

ERIC Educational Resources Information Center

Gligorovic, Milica; Vucinic, Vesna; Eskirovic, Branka; Jablan, Branka

2011-01-01

This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest…

Integrating multi-view transmission system into MPEG-21 stereoscopic and multi-view DIA (digital item adaptation)

NASA Astrophysics Data System (ADS)

Lee, Seungwon; Park, Ilkwon; Kim, Manbae; Byun, Hyeran

2006-10-01

As digital broadcasting technologies have been rapidly progressed, users' expectations for realistic and interactive broadcasting services also have been increased. As one of such services, 3D multi-view broadcasting has received much attention recently. In general, all the view sequences acquired at the server are transmitted to the client. Then, the user can select a part of views or all the views according to display capabilities. However, this kind of system requires high processing power of the server as well as the client, thus posing a difficulty in practical applications. To overcome this problem, a relatively simple method is to transmit only two view-sequences requested by the client in order to deliver a stereoscopic video. In this system, effective communication between the server and the client is one of important aspects. In this paper, we propose an efficient multi-view system that transmits two view-sequences and their depth maps according to user's request. The view selection process is integrated into MPEG-21 DIA (Digital Item Adaptation) so that our system is compatible to MPEG-21 multimedia framework. DIA is generally composed of resource adaptation and descriptor adaptation. It is one of merits that SVA (stereoscopic video adaptation) descriptors defined in DIA standard are used to deliver users' preferences and device capabilities. Furthermore, multi-view descriptions related to multi-view camera and system are newly introduced. The syntax of the descriptions and their elements is represented in XML (eXtensible Markup Language) schema. If the client requests an adapted descriptor (e.g., view numbers) to the server, then the server sends its associated view sequences. Finally, we present a method which can reduce user's visual discomfort that might occur while viewing stereoscopic video. This phenomenon happens when view changes as well as when a stereoscopic image produces excessive disparity caused by a large baseline between two cameras. To solve for the former, IVR (intermediate view reconstruction) is employed for smooth transition between two stereoscopic view sequences. As well, a disparity adjustment scheme is used for the latter. Finally, from the implementation of testbed and the experiments, we can show the valuables and possibilities of our system.

View generation for 3D-TV using image reconstruction from irregularly spaced samples

NASA Astrophysics Data System (ADS)

Vázquez, Carlos

2007-02-01

Three-dimensional television (3D-TV) will become the next big step in the development of advanced TV systems. One of the major challenges for the deployment of 3D-TV systems is the diversity of display technologies and the high cost of capturing multi-view content. Depth image-based rendering (DIBR) has been identified as a key technology for the generation of new views for stereoscopic and multi-view displays from a small number of views captured and transmitted. We propose a disparity compensation method for DIBR that does not require spatial interpolation of the disparity map. We use a forward-mapping disparity compensation with real precision. The proposed method deals with the irregularly sampled image resulting from this disparity compensation process by applying a re-sampling algorithm based on a bi-cubic spline function space that produces smooth images. The fact that no approximation is made on the position of the samples implies that geometrical distortions in the final images due to approximations in sample positions are minimized. We also paid attention to the occlusion problem. Our algorithm detects the occluded regions in the newly generated images and uses simple depth-aware inpainting techniques to fill the gaps created by newly exposed areas. We tested the proposed method in the context of generation of views needed for viewing on SynthaGram TM auto-stereoscopic displays. We used as input either a 2D image plus a depth map or a stereoscopic pair with the associated disparity map. Our results show that this technique provides high quality images to be viewed on different display technologies such as stereoscopic viewing with shutter glasses (two views) and lenticular auto-stereoscopic displays (nine views).

Identification of depth information with stereoscopic mammography using different display methods

NASA Astrophysics Data System (ADS)

Morikawa, Takamitsu; Kodera, Yoshie

2013-03-01

Stereoscopy in radiography was widely used in the late 80's because it could be used for capturing complex structures in the human body, thus proving beneficial for diagnosis and screening. When radiologists observed the images stereoscopically, radiologists usually needed the training of their eyes in order to perceive the stereoscopic effect. However, with the development of three-dimensional (3D) monitors and their use in the medical field, only a visual inspection is no longer required in the medical field. The question then arises as to whether there is any difference in recognizing depth information when using conventional methods and that when using a 3D monitor. We constructed a phantom and evaluated the difference in capacity to identify the depth information between the two methods. The phantom consists of acryl steps and 3mm diameter acryl pillars on the top and bottom of each step. Seven observers viewed these images stereoscopically using the two display methods and were asked to judge the direction of the pillar that was on the top. We compared these judged direction with the direction of the real pillar arranged on the top, and calculated the percentage of correct answerers (PCA). The results showed that PCA obtained using the 3D monitor method was higher PCA by about 5% than that obtained using the naked-eye method. This indicated that people could view images stereoscopically more precisely using the 3D monitor method than when using with conventional methods, like the crossed or parallel eye viewing. We were able to estimate the difference in capacity to identify the depth information between the two display methods.

An optimized web-based approach for collaborative stereoscopic medical visualization

PubMed Central

Kaspar, Mathias; Parsad, Nigel M; Silverstein, Jonathan C

2013-01-01

Objective Medical visualization tools have traditionally been constrained to tethered imaging workstations or proprietary client viewers, typically part of hospital radiology systems. To improve accessibility to real-time, remote, interactive, stereoscopic visualization and to enable collaboration among multiple viewing locations, we developed an open source approach requiring only a standard web browser with no added client-side software. Materials and Methods Our collaborative, web-based, stereoscopic, visualization system, CoWebViz, has been used successfully for the past 2 years at the University of Chicago to teach immersive virtual anatomy classes. It is a server application that streams server-side visualization applications to client front-ends, comprised solely of a standard web browser with no added software. Results We describe optimization considerations, usability, and performance results, which make CoWebViz practical for broad clinical use. We clarify technical advances including: enhanced threaded architecture, optimized visualization distribution algorithms, a wide range of supported stereoscopic presentation technologies, and the salient theoretical and empirical network parameters that affect our web-based visualization approach. Discussion The implementations demonstrate usability and performance benefits of a simple web-based approach for complex clinical visualization scenarios. Using this approach overcomes technical challenges that require third-party web browser plug-ins, resulting in the most lightweight client. Conclusions Compared to special software and hardware deployments, unmodified web browsers enhance remote user accessibility to interactive medical visualization. Whereas local hardware and software deployments may provide better interactivity than remote applications, our implementation demonstrates that a simplified, stable, client approach using standard web browsers is sufficient for high quality three-dimensional, stereoscopic, collaborative and interactive visualization. PMID:23048008

Accommodation response measurements for integral 3D image

NASA Astrophysics Data System (ADS)

Hiura, H.; Mishina, T.; Arai, J.; Iwadate, Y.

2014-03-01

We measured accommodation responses under integral photography (IP), binocular stereoscopic, and real object display conditions, and viewing conditions of binocular and monocular viewing conditions. The equipment we used was an optometric device and a 3D display. We developed the 3D display for IP and binocular stereoscopic images that comprises a high-resolution liquid crystal display (LCD) and a high-density lens array. The LCD has a resolution of 468 dpi and a diagonal size of 4.8 inches. The high-density lens array comprises 106 x 69 micro lenses that have a focal length of 3 mm and diameter of 1 mm. The lenses are arranged in a honeycomb pattern. The 3D display was positioned 60 cm from an observer under IP and binocular stereoscopic display conditions. The target was presented at eight depth positions relative to the 3D display: 15, 10, and 5 cm in front of the 3D display, on the 3D display panel, and 5, 10, 15 and 30 cm behind the 3D display under the IP and binocular stereoscopic display conditions. Under the real object display condition, the target was displayed on the 3D display panel, and the 3D display was placed at the eight positions. The results suggest that the IP image induced more natural accommodation responses compared to the binocular stereoscopic image. The accommodation responses of the IP image were weaker than those of a real object; however, they showed a similar tendency with those of the real object under the two viewing conditions. Therefore, IP can induce accommodation to the depth positions of 3D images.

Evaluation of a stereoscopic camera-based three-dimensional viewing workstation for ophthalmic surgery.

PubMed

Bhadri, Prashant R; Rowley, Adrian P; Khurana, Rahul N; Deboer, Charles M; Kerns, Ralph M; Chong, Lawrence P; Humayun, Mark S

2007-05-01

To evaluate the effectiveness of a prototype stereoscopic camera-based viewing system (Digital Microsurgical Workstation, three-dimensional (3D) Vision Systems, Irvine, California, USA) for anterior and posterior segment ophthalmic surgery. Institutional-based prospective study. Anterior and posterior segment surgeons performed designated standardized tasks on porcine eyes after training on prosthetic plastic eyes. Both anterior and posterior segment surgeons were able to complete tasks requiring minimal or moderate stereoscopic viewing. The results indicate that the system provides improved ergonomics. Improvements in key viewing performance areas would further enhance the value over a conventional operating microscope. The performance of the prototype system is not at par with the planned commercial system. With continued development of this technology, the three- dimensional system may be a novel viewing system in ophthalmic surgery with improved ergonomics with respect to traditional microscopic viewing.

Reducing Visual Discomfort with HMDs Using Dynamic Depth of Field.

PubMed

Carnegie, Kieran; Rhee, Taehyun

2015-01-01

Although head-mounted displays (HMDs) are ideal devices for personal viewing of immersive stereoscopic content, exposure to VR applications on them results in significant discomfort for the majority of people, with symptoms including eye fatigue, headaches, nausea, and sweating. A conflict between accommodation and vergence depth cues on stereoscopic displays is a significant cause of visual discomfort. This article describes the results of an evaluation used to judge the effectiveness of dynamic depth-of-field (DoF) blur in an effort to reduce discomfort caused by exposure to stereoscopic content on HMDs. Using a commercial game engine implementation, study participants report a reduction of visual discomfort on a simulator sickness questionnaire when DoF blurring is enabled. The study participants reported a decrease in symptom severity caused by HMD exposure, indicating that dynamic DoF can effectively reduce visual discomfort.

The Real Time Correction of Stereoscopic Images: From the Serial to a Parallel Treatment

NASA Astrophysics Data System (ADS)

Irki, Zohir; Devy, Michel; Achour, Karim; Azzaz, Mohamed Salah

2008-06-01

The correction of the stereoscopic images is a task which consists in replacing acquired images by other images having the same properties but which are simpler to use in the other stages of stereovision. The use of the pre-calculated tables, built during an off line calibration step, made it possible to carry out the off line stereoscopic images rectification. An improvement of the built tables made it possible to carry out the real time rectification. In this paper, we describe an improvement of the real time correction approach so it can be exploited for a possible implementation on an FPGA component. This improvement holds in account the real time aspect of the correction and the available resources that can offer the FPGA Type Stratix 1S40F780C5.

Current status of stereoscopic 3D LCD TV technologies

NASA Astrophysics Data System (ADS)

Choi, Hee-Jin

2011-06-01

The year 2010 may be recorded as a first year of successful commercial 3D products. Among them, the 3D LCD TVs are expected to be the major one regarding the sales volume. In this paper, the principle of current stereoscopic 3D LCD TV techniques and the required flat panel display (FPD) technologies for the realization of them are reviewed. [Figure not available: see fulltext.

Case study: the introduction of stereoscopic games on the Sony PlayStation 3

NASA Astrophysics Data System (ADS)

Bickerstaff, Ian

2012-03-01

A free stereoscopic firmware update on Sony Computer Entertainment's PlayStation® 3 console provides the potential to increase enormously the popularity of stereoscopic 3D in the home. For this to succeed though, a large selection of content has to become available that exploits 3D in the best way possible. In addition to the existing challenges found in creating 3D movies and television programmes, the stereography must compensate for the dynamic and unpredictable environments found in games. Automatically, the software must map the depth range of the scene into the display's comfort zone, while minimising depth compression. This paper presents a range of techniques developed to solve this problem and the challenge of creating twice as many images as the 2D version without excessively compromising the frame rate or image quality. At the time of writing, over 80 stereoscopic PlayStation 3 games have been released and notable titles are used as examples to illustrate how the techniques have been adapted for different game genres. Since the firmware's introduction in 2010, the industry has matured with a large number of developers now producing increasingly sophisticated 3D content. New technologies such as viewer head tracking and head-mounted displays should increase the appeal of 3D in the home still further.

Advanced autostereoscopic display for G-7 pilot project

NASA Astrophysics Data System (ADS)

Hattori, Tomohiko; Ishigaki, Takeo; Shimamoto, Kazuhiro; Sawaki, Akiko; Ishiguchi, Tsuneo; Kobayashi, Hiromi

1999-05-01

An advanced auto-stereoscopic display is described that permits the observation of a stereo pair by several persons simultaneously without the use of special glasses and any kind of head tracking devices for the viewers. The system is composed of a right eye system, a left eye system and a sophisticated head tracking system. In the each eye system, a transparent type color liquid crystal imaging plate is used with a special back light unit. The back light unit consists of a monochrome 2D display and a large format convex lens. The unit distributes the light of the viewers' correct each eye only. The right eye perspective system is combined with a left eye perspective system is combined with a left eye perspective system by a half mirror in order to function as a time-parallel stereoscopic system. The viewer's IR image is taken through and focused by the large format convex lens and feed back to the back light as a modulated binary half face image. The auto-stereoscopic display employs the TTL method as the accurate head tracking. The system was worked as a stereoscopic TV phone between Duke University Department Tele-medicine and Nagoya University School of Medicine Department Radiology using a high-speed digital line of GIBN. The applications are also described in this paper.

Persistent Monitoring of Urban Infrasound Phenomenology. Report 1: Modeling an Urban Environment for Acoustical Analyses using the 3-D Finite-Difference Time-Domain Program PSTOP3D

DTIC Science & Technology

2015-08-01

a definition of the building footprints with an associated height attribute. This would be enough information to construct an extruded building ...contract was undertaken with CyberCity 3D (2012), a commercial company located in El Segundo, CA, to construct the buildings . The company specializes in...visualization of planning functions. CyberCity 3D used 6 in. stereoscopic aerial photography to construct 3-D models of the buildings . These models were quite

Stereoscopic neuroanatomy lectures using a three-dimensional virtual reality environment.

PubMed

Kockro, Ralf A; Amaxopoulou, Christina; Killeen, Tim; Wagner, Wolfgang; Reisch, Robert; Schwandt, Eike; Gutenberg, Angelika; Giese, Alf; Stofft, Eckart; Stadie, Axel T

2015-09-01

Three-dimensional (3D) computer graphics are increasingly used to supplement the teaching of anatomy. While most systems consist of a program which produces 3D renderings on a workstation with a standard screen, the Dextrobeam virtual reality VR environment allows the presentation of spatial neuroanatomical models to larger groups of students through a stereoscopic projection system. Second-year medical students (n=169) were randomly allocated to receive a standardised pre-recorded audio lecture detailing the anatomy of the third ventricle accompanied by either a two-dimensional (2D) PowerPoint presentation (n=80) or a 3D animated tour of the third ventricle with the DextroBeam. Students completed a 10-question multiple-choice exam based on the content learned and a subjective evaluation of the teaching method immediately after the lecture. Students in the 2D group achieved a mean score of 5.19 (±2.12) compared to 5.45 (±2.16) in the 3D group, with the results in the 3D group statistically non-inferior to those of the 2D group (p<0.0001). The students rated the 3D method superior to 2D teaching in four domains (spatial understanding, application in future anatomy classes, effectiveness, enjoyableness) (p<0.01). Stereoscopically enhanced 3D lectures are valid methods of imparting neuroanatomical knowledge and are well received by students. More research is required to define and develop the role of large-group VR systems in modern neuroanatomy curricula. Copyright © 2015 Elsevier GmbH. All rights reserved.

Solar Rotation Stereoscopy in Microwaves

NASA Astrophysics Data System (ADS)

Aschwanden, Markus J.; Lim, Jeremy; Gary, Dale E.; Klimchuk, James A.

1995-11-01

We present here the first stereoscopic altitude measurements of active region sources observed at microwave frequencies (10-14 GHz The active region NOAA 7128 was observed with the Owens Valley Radio Observatory (OVRO) on 1992 April 13, 14, 15, and 16 as it passed through the central meridian. From white-light data of the underlying sunspot we determined the rotation rate of the active region, which was found to have a relative motion of dL/dt = +0°.240 day-1 with respect to the standard photospheric differential rotation rate. Based on this rotation rate we determine for the microwave sources stereoscopic altitudes of 3.3-11.0 Mm above the photosphere. The altitude spectrum h(v) of the right circular polarization (RCP) main source shows a discontinuity at 12 GHz and can be satisfactorily fitted with a dipole model with a transition from the second to the third harmonic level at 12 GHz. The dominance of the third harmonic for frequencies above 12 GHz occurs because the second harmonic level drops below the transition region, at a height of 2.6±0.6 Mm according to the microwave data. The altitude spectrum h(v) serves also to invert the temperature profile T(h) from the optically thick parts of the radio brightness temperature spectrum TB(ν[h]). The microwave emission in both circular polarizations can be modeled with gyroresonance emission, with x-mode for RCP and o-mode in LCP, with the same harmonics at each frequency, but different emission angles in both modes. The contributions from free-free emission are negligible in both polarizations, based on the peak emission measure of EM ≍ 6 × 1028 cm-5 observed in soft X-rays by Yohkoh/SXT. This study demonstrates that the height dependence of the coronal magnetic field B(h) and the plasma temperature T(h) in an active region can be inverted from the stereoscopic altitude spectra h(v) and the observed brightness temperature spectra TB(ν).

Stereosat: A proposed private sector/government joint venture in remote sensing from space

NASA Technical Reports Server (NTRS)

Anglin, R. L.

1980-01-01

Stereosat, a free flying Sun synchronous satellite whose purpose is to obtain worldwide cloud-free stereoscopic images of the Earth's land masses, is proposed as a joint private sector/government venture. A number of potential organization models are identified. The legal, economic, and institutional issues which could impact the continuum of potential joint private sector/government institutional structures are examined.

Effects of Stereoscopic 3D Digital Radar Displays on Air Traffic Controller Performance

DTIC Science & Technology

2013-03-01

between men and women , but no significant influence was found. Experience in ATC was considered as a potential covariate that would be presumed to have...depicts altitude through the use of stereoscopic disparity, permitting vertical separation to be visually represented as differences in disparity...handling information via different sources (e.g., radar screen with a series of automated visual cues, paper or electronic flight progress strips, radio

Variation and extrema of human interpupillary distance

NASA Astrophysics Data System (ADS)

Dodgson, Neil A.

2004-05-01

Mean interpupillary distance (IPD) is an important and oft-quoted measure in stereoscopic work. However, there is startlingly little agreement on what it should be. Mean IPD has been quoted in the stereoscopic literature as being anything from 58 mm to 70 mm. It is known to vary with respect to age, gender and race. Furthermore, the stereoscopic industry requires information on not just mean IPD, but also its variance and its extrema, because our products need to be able to cope with all possible users, including those with the smallest and largest IPDs. This paper brings together those statistics on IPD which are available. The key results are that mean adult IPD is around 63 mm, the vast majority of adults have IPDs in the range 50-75 mm, the wider range of 45-80 mm is likely to include (almost) all adults, and the minimum IPD for children (down to five years old) is around 40 mm.

Self-calibration performance in stereoscopic PIV acquired in a transonic wind tunnel

DOE PAGES

Beresh, Steven J.; Wagner, Justin L.; Smith, Barton L.

2016-03-16

Three stereoscopic PIV experiments have been examined to test the effectiveness of self-calibration under varied circumstances. Furthermore, we our measurements taken in a streamwise plane yielded a robust self-calibration that returned common results regardless of the specific calibration procedure, but measurements in the crossplane exhibited substantial velocity bias errors whose nature was sensitive to the particulars of the self-calibration approach. Self-calibration is complicated by thick laser sheets and large stereoscopic camera angles and further exacerbated by small particle image diameters and high particle seeding density. In spite of the different answers obtained by varied self-calibrations, each implementation locked onto anmore » apparently valid solution with small residual disparity and converged adjustment of the calibration plane. Thus, the convergence of self-calibration on a solution with small disparity is not sufficient to indicate negligible velocity error due to the stereo calibration.« less

The Effect of Stereoscopic ("3D") vs. 2D Presentation on Learning through Video and Film

NASA Astrophysics Data System (ADS)

Price, Aaron; Kasal, E.

2014-01-01

Two Eyes, 3D is a NSF-funded research project into the effects of stereoscopy on learning of highly spatial concepts. We report final results on one study of the project which tested the effect of stereoscopic presentation on learning outcomes of two short films about Type 1a supernovae and the morphology of the Milky Way. 986 adults watched either film, randomly distributed between stereoscopic and 2D presentation. They took a pre-test and post-test that included multiple choice and drawing tasks related to the spatial nature of the topics in the film. Orientation of the answering device was also tracked and a spatial cognition pre-test was given to control for prior spatial ability. Data collection took place at the Adler Planetarium's Space Visualization Lab and the project is run through the AAVSO.

Optimizing visual comfort for stereoscopic 3D display based on color-plus-depth signals.

PubMed

Shao, Feng; Jiang, Qiuping; Fu, Randi; Yu, Mei; Jiang, Gangyi

2016-05-30

Visual comfort is a long-facing problem in stereoscopic 3D (S3D) display. In this paper, targeting to produce S3D content based on color-plus-depth signals, a general framework for depth mapping to optimize visual comfort for S3D display is proposed. The main motivation of this work is to remap the depth range of color-plus-depth signals to a new depth range that is suitable to comfortable S3D display. Towards this end, we first remap the depth range globally based on the adjusted zero disparity plane, and then present a two-stage global and local depth optimization solution to solve the visual comfort problem. The remapped depth map is used to generate the S3D output. We demonstrate the power of our approach on perceptually uncomfortable and comfortable stereoscopic images.

Effects of cortical damage on binocular depth perception.

PubMed

Bridge, Holly

2016-06-19

Stereoscopic depth perception requires considerable neural computation, including the initial correspondence of the two retinal images, comparison across the local regions of the visual field and integration with other cues to depth. The most common cause for loss of stereoscopic vision is amblyopia, in which one eye has failed to form an adequate input to the visual cortex, usually due to strabismus (deviating eye) or anisometropia. However, the significant cortical processing required to produce the percept of depth means that, even when the retinal input is intact from both eyes, brain damage or dysfunction can interfere with stereoscopic vision. In this review, I examine the evidence for impairment of binocular vision and depth perception that can result from insults to the brain, including both discrete damage, temporal lobectomy and more systemic diseases such as posterior cortical atrophy.This article is part of the themed issue 'Vision in our three-dimensional world'. © 2016 The Authors.

Effects of cortical damage on binocular depth perception

PubMed Central

2016-01-01

Stereoscopic depth perception requires considerable neural computation, including the initial correspondence of the two retinal images, comparison across the local regions of the visual field and integration with other cues to depth. The most common cause for loss of stereoscopic vision is amblyopia, in which one eye has failed to form an adequate input to the visual cortex, usually due to strabismus (deviating eye) or anisometropia. However, the significant cortical processing required to produce the percept of depth means that, even when the retinal input is intact from both eyes, brain damage or dysfunction can interfere with stereoscopic vision. In this review, I examine the evidence for impairment of binocular vision and depth perception that can result from insults to the brain, including both discrete damage, temporal lobectomy and more systemic diseases such as posterior cortical atrophy. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269597

Continuous monitoring of prostate position using stereoscopic and monoscopic kV image guidance

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

Stevens, M. Tynan R.; Parsons, Dave D.; Robar, James L.

2016-05-15

Purpose: To demonstrate continuous kV x-ray monitoring of prostate motion using both stereoscopic and monoscopic localizations, assess the spatial accuracy of these techniques, and evaluate the dose delivered from the added image guidance. Methods: The authors implemented both stereoscopic and monoscopic fiducial localizations using a room-mounted dual oblique x-ray system. Recently developed monoscopic 3D position estimation techniques potentially overcome the issue of treatment head interference with stereoscopic imaging at certain gantry angles. To demonstrate continuous position monitoring, a gold fiducial marker was placed in an anthropomorphic phantom and placed on the Linac couch. The couch was used as a programmablemore » translation stage. The couch was programmed with a series of patient prostate motion trajectories exemplifying five distinct categories: stable prostate, slow drift, persistent excursion, transient excursion, and high frequency excursions. The phantom and fiducial were imaged using 140 kVp, 0.63 mAs per image at 1 Hz for a 60 s monitoring period. Both stereoscopic and monoscopic 3D localization accuracies were assessed by comparison to the ground-truth obtained from the Linac log file. Imaging dose was also assessed, using optically stimulated luminescence dosimeter inserts in the phantom. Results: Stereoscopic localization accuracy varied between 0.13 ± 0.05 and 0.33 ± 0.30 mm, depending on the motion trajectory. Monoscopic localization accuracy varied from 0.2 ± 0.1 to 1.1 ± 0.7 mm. The largest localization errors were typically observed in the left–right direction. There were significant differences in accuracy between the two monoscopic views, but which view was better varied from trajectory to trajectory. The imaging dose was measured to be between 2 and 15 μGy/mAs, depending on location in the phantom. Conclusions: The authors have demonstrated the first use of monoscopic localization for a room-mounted dual x-ray system. Three-dimensional position estimation from monoscopic imaging permits continuous, uninterrupted intrafraction motion monitoring even in the presence of gantry rotation, which may block kV sources or imagers. This potentially allows for more accurate treatment delivery, by ensuring that the prostate does not deviate substantially from the initial setup position.« less

Stereoscopic observations from meteorological satellites

NASA Astrophysics Data System (ADS)

Hasler, A. F.; Mack, R.; Negri, A.

The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk et al. [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner et al. [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler et al. [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated. Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the two satellites. A general solution for accurate height computation depends on precise navigation of the two satellites. Validation of the geosynchronous satellite stereo using high altitude mountain lakes and vertically pointing aircraft lidar leads to a height accuracy estimate of +/- 500 m for typical clouds which have been studied. Applications of the satellite stereo include: 1) cloud top and base height measurements, 2) cloud-wind height assignment, 3) vertical motion estimates for convective clouds (Mack et al. [13], [14]), 4) temperature vs. height measurements when stereo is used together with infrared observations and 5) cloud emissivity measurements when stereo, infrared and temperature sounding are used together (see Szejwach et al. [15]). When true satellite stereo image pairs are not available, synthetic stereo may be generated. The combination of multispectral satellite data using computer produced stereo image pairs is a dramatic example of synthetic stereoscopic display. The classic case uses the combination of infrared and visible data as first demonstrated by Pichel et al. [16]. Hasler et at. [17], Mosher and Young [18] and Lorenz [19], have expanded this concept to display many channels of data from various radiometers as well as real and simulated data fields. A future system of stereoscopic satellites would be comprised of both low orbiters (as suggested by Lorenz and Schmidt [20], [19]) and a global system of geosynchronous satellites. The low earth orbiters would provide stereo coverage day and night and include the poles. An optimum global system of stereoscopic geosynchronous satellites would require international standarization of scan rate and direction, and scan times (synchronization) and resolution of at least 1 km in all imaging channels. A stereoscopic satellite system as suggested here would make an extremely important contribution to the understanding and prediction of the atmosphere.

A systematized WYSIWYG pipeline for digital stereoscopic 3D filmmaking

NASA Astrophysics Data System (ADS)

Mueller, Robert; Ward, Chris; Hušák, Michal

2008-02-01

Digital tools are transforming stereoscopic 3D content creation and delivery, creating an opportunity for the broad acceptance and success of stereoscopic 3D films. Beginning in late 2005, a series of mostly CGI features has successfully initiated the public to this new generation of highly-comfortable, artifact-free digital 3D. While the response has been decidedly favorable, a lack of high-quality live-action films could hinder long-term success. Liveaction stereoscopic films have historically been more time-consuming, costly, and creatively-limiting than 2D films - thus a need arises for a live-action 3D filmmaking process which minimizes such limitations. A unique 'systematized' what-you-see-is-what-you-get (WYSIWYG) pipeline is described which allows the efficient, intuitive and accurate capture and integration of 3D and 2D elements from multiple shoots and sources - both live-action and CGI. Throughout this pipeline, digital tools utilize a consistent algorithm to provide meaningful and accurate visual depth references with respect to the viewing audience in the target theater environment. This intuitive, visual approach introduces efficiency and creativity to the 3D filmmaking process by eliminating both the need for a 'mathematician mentality' of spreadsheets and calculators, as well as any trial and error guesswork, while enabling the most comfortable, 'pixel-perfect', artifact-free 3D product possible.

Intra-operative prostate motion tracking using surface markers for robot-assisted laparoscopic radical prostatectomy

NASA Astrophysics Data System (ADS)

Esteghamatian, Mehdi; Sarkar, Kripasindhu; Pautler, Stephen E.; Chen, Elvis C. S.; Peters, Terry M.

2012-02-01

Radical prostatectomy surgery (RP) is the gold standard for treatment of localized prostate cancer (PCa). Recently, emergence of minimally invasive techniques such as Laparoscopic Radical Prostatectomy (LRP) and Robot-Assisted Laparoscopic Radical Prostatectomy (RARP) has improved the outcomes for prostatectomy. However, it remains difficult for the surgeons to make informed decisions regarding resection margins and nerve sparing since the location of the tumor within the organ is not usually visible in a laparoscopic view. While MRI enables visualization of the salient structures and cancer foci, its efficacy in LRP is reduced unless it is fused into a stereoscopic view such that homologous structures overlap. Registration of the MRI image and peri-operative ultrasound image using a tracked probe can potentially be exploited to bring the pre-operative information into alignment with the patient coordinate system during the procedure. While doing so, prostate motion needs to be compensated in real-time to synchronize the stereoscopic view with the pre-operative MRI during the prostatectomy procedure. In this study, a point-based stereoscopic tracking technique is investigated to compensate for rigid prostate motion so that the same motion can be applied to the pre-operative images. This method benefits from stereoscopic tracking of the surface markers implanted over the surface of the prostate phantom. The average target registration error using this approach was 3.25+/-1.43mm.

Recovering stereo vision by squashing virtual bugs in a virtual reality environment.

PubMed

Vedamurthy, Indu; Knill, David C; Huang, Samuel J; Yung, Amanda; Ding, Jian; Kwon, Oh-Sang; Bavelier, Daphne; Levi, Dennis M

2016-06-19

Stereopsis is the rich impression of three-dimensionality, based on binocular disparity-the differences between the two retinal images of the same world. However, a substantial proportion of the population is stereo-deficient, and relies mostly on monocular cues to judge the relative depth or distance of objects in the environment. Here we trained adults who were stereo blind or stereo-deficient owing to strabismus and/or amblyopia in a natural visuomotor task-a 'bug squashing' game-in a virtual reality environment. The subjects' task was to squash a virtual dichoptic bug on a slanted surface, by hitting it with a physical cylinder they held in their hand. The perceived surface slant was determined by monocular texture and stereoscopic cues, with these cues being either consistent or in conflict, allowing us to track the relative weighting of monocular versus stereoscopic cues as training in the task progressed. Following training most participants showed greater reliance on stereoscopic cues, reduced suppression and improved stereoacuity. Importantly, the training-induced changes in relative stereo weights were significant predictors of the improvements in stereoacuity. We conclude that some adults deprived of normal binocular vision and insensitive to the disparity information can, with appropriate experience, recover access to more reliable stereoscopic information.This article is part of the themed issue 'Vision in our three-dimensional world'. © 2016 The Author(s).

Recovering stereo vision by squashing virtual bugs in a virtual reality environment

PubMed Central

Vedamurthy, Indu; Knill, David C.; Huang, Samuel J.; Yung, Amanda; Ding, Jian; Kwon, Oh-Sang; Bavelier, Daphne

2016-01-01

Stereopsis is the rich impression of three-dimensionality, based on binocular disparity—the differences between the two retinal images of the same world. However, a substantial proportion of the population is stereo-deficient, and relies mostly on monocular cues to judge the relative depth or distance of objects in the environment. Here we trained adults who were stereo blind or stereo-deficient owing to strabismus and/or amblyopia in a natural visuomotor task—a ‘bug squashing’ game—in a virtual reality environment. The subjects' task was to squash a virtual dichoptic bug on a slanted surface, by hitting it with a physical cylinder they held in their hand. The perceived surface slant was determined by monocular texture and stereoscopic cues, with these cues being either consistent or in conflict, allowing us to track the relative weighting of monocular versus stereoscopic cues as training in the task progressed. Following training most participants showed greater reliance on stereoscopic cues, reduced suppression and improved stereoacuity. Importantly, the training-induced changes in relative stereo weights were significant predictors of the improvements in stereoacuity. We conclude that some adults deprived of normal binocular vision and insensitive to the disparity information can, with appropriate experience, recover access to more reliable stereoscopic information. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269607

Stereoscopic virtual reality models for planning tumor resection in the sellar region.

PubMed

Wang, Shou-sen; Zhang, Shang-ming; Jing, Jun-jie

2012-11-28

It is difficult for neurosurgeons to perceive the complex three-dimensional anatomical relationships in the sellar region. To investigate the value of using a virtual reality system for planning resection of sellar region tumors. The study included 60 patients with sellar tumors. All patients underwent computed tomography angiography, MRI-T1W1, and contrast enhanced MRI-T1W1 image sequence scanning. The CT and MRI scanning data were collected and then imported into a Dextroscope imaging workstation, a virtual reality system that allows structures to be viewed stereoscopically. During preoperative assessment, typical images for each patient were chosen and printed out for use by the surgeons as references during surgery. All sellar tumor models clearly displayed bone, the internal carotid artery, circle of Willis and its branches, the optic nerve and chiasm, ventricular system, tumor, brain, soft tissue and adjacent structures. Depending on the location of the tumors, we simulated the transmononasal sphenoid sinus approach, transpterional approach, and other approaches. Eleven surgeons who used virtual reality models completed a survey questionnaire. Nine of the participants said that the virtual reality images were superior to other images but that other images needed to be used in combination with the virtual reality images. The three-dimensional virtual reality models were helpful for individualized planning of surgery in the sellar region. Virtual reality appears to be promising as a valuable tool for sellar region surgery in the future.

Real-Time Mapping Using Stereoscopic Vision Optimization

DTIC Science & Technology

2005-03-01

pinhole geometry . . . . . . . . . . . . . . 17 2.8. Artificially textured scenes . . . . . . . . . . . . . . . . . . . . 23 3.1. Bilbo the robot...geometry. 2.2.1 The Fundamental Matrix. The fundamental matrix (F) describes the relationship between a pair of 2D pictures of a 3D scene . This is...eight CCD cameras to compute a mesh model of the environment from a large number of overlapped 3D images. In [1,17], a range scanner is combined with a

Analysis of tooth marks in a homicide case. Observations by means of visual description, stereo-photography, scanning electron microscopy and stereometric graphic plotting.

PubMed

Bang, G

1976-01-01

In 1957 a woman was murdered in Oslo. Her left breast exhibited tooth marks. A man was arrested and sentenced to life imprisonment partly because of the dental evidence. He never admitted guilt and filed a petition for retrial. The present author was appointed as new dental expert. The material consisted of the fixed breast, models of the bite mark and models of the teeth of the convict, and several photographs. By means of visual examination, a magnifying glass, a lens stereoscope and a stereomicroscope characteristic details were noted. Stereoscopic picture pairs were taken, the material was studied by means of scanning electron microscopy and a stereometricgraphic plotting method permitting the outline of the tooth mark or the biting edge of a tooth to be registered in great detail in all three dimensions in the form of a contour map. This method has not previously been applied in the analysis of tooth marks in human skin. These examinations revealed no discrepancies but showed many corresponding characteristic features between the tooth marks and the teeth of the convict, resulting in the conclusion that it is highly probable that the tooth marks in the breast were made by the teeth of the convict.

Measurements of the spatial structure and directivity of 100 KeV photon sources in solar flares using PVO and ISEE-3 spacecraft

NASA Technical Reports Server (NTRS)

Anderson, Kinsey A.

1991-01-01

The objective of this grant was to measure the spatial structure and directivity of the hard X-ray and low energy gamma-ray (100 keV-2 MeV) continuum sources in solar flares using stereoscopic observations made with spectrometers aboard the Pioneer Venus Orbiter (PVO) and Third International Sun Earth Explorer (ISEE-3) spacecraft. Since the hard X-ray emission is produced by energetic electrons through the bremsstrahlung process, the observed directivity can be directly related to the 'beaming' of electrons accelerated during the flare as they propagate from the acceleration region in the corona to the chromosphere/transition region. Some models (e.g., the thick-target model) predict that most of the impulsive hard X-ray/low energy gamma-ray source is located in the chromosphere, the effective height of the X-ray source above the photosphere increasing with the decrease in the photon energy. This can be verified by determining the height-dependence of the photon source through stereoscopic observations of those flares which are partially occulted from the view of one of the two spacecraft. Thus predictions about beaming of electrons as well as their spatial distributions could be tested through the analysis proposed under this grant.

3-D Digitization of Stereoscopic Jet-in-Crossflow Vortex Structure Images via Augmented Reality

NASA Astrophysics Data System (ADS)

Sigurdson, Lorenz; Strand, Christopher; Watson, Graeme; Nault, Joshua; Tucker, Ryan

2006-11-01

Stereoscopic images of smoke-laden vortex flows have proven useful for understanding the topology of the embedded 3-D vortex structures. Images from two cameras allow a perception of the 3-D structure via the use of red/blue eye glasses. The human brain has an astonishing capacity to calculate and present to the observer the complex turbulent smoke volume. We have developed a technique whereby a virtual cursor is introduced to the perception, which creates an ``augmented reality.'' The perceived position of this cursor in the 3-D field can be precisely controlled by the observer. It can be brought near a characteristic vortex structure in order to digitally estimate the spatial coordinates of that feature. A calibration procedure accounts for camera positioning. Vortex tubes can be traced and recorded for later or real time supersposition of tube skeleton models. These models can be readily digitally obtained for display in graphics systems to allow complete exploration from any location or perspective. A unique feature of this technology is the use of the human brain to naturally perform the difficult computation of the shape of the translucent smoke volume. Examples are given of application to low velocity ratio and Reynolds number elevated jets-in-crossflow.

Stereoscopic game design and evaluation

NASA Astrophysics Data System (ADS)

Rivett, Joe; Holliman, Nicolas

2013-03-01

We report on a new game design where the goal is to make the stereoscopic depth cue sufficiently critical to success that game play should become impossible without using a stereoscopic 3D (S3D) display and, at the same time, we investigate whether S3D game play is affected by screen size. Before we detail our new game design we review previously unreported results from our stereoscopic game research over the last ten years at the Durham Visualisation Laboratory. This demonstrates that game players can achieve significantly higher scores using S3D displays when depth judgements are an integral part of the game. Method: We design a game where almost all depth cues, apart from the binocular cue, are removed. The aim of the game is to steer a spaceship through a series of oncoming hoops where the viewpoint of the game player is from above, with the hoops moving right to left across the screen towards the spaceship, to play the game it is essential to make decisive depth judgments to steer the spaceship through each oncoming hoop. To confound these judgements we design altered depth cues, for example perspective is reduced as a cue by varying the hoop's depth, radius and cross-sectional size. Results: Players were screened for stereoscopic vision, given a short practice session, and then played the game in both 2D and S3D modes on a seventeen inch desktop display, on average participants achieved a more than three times higher score in S3D than they achieved in 2D. The same experiment was repeated using a four metre S3D projection screen and similar results were found. Conclusions: Our conclusion is that games that use the binocular depth cue in decisive game judgements can benefit significantly from using an S3D display. Based on both our current and previous results we additionally conclude that display size, from cell-phone, to desktop, to projection display does not adversely affect player performance.

Stereo study as an aid to visual analysis of ERTS and Skylab images

NASA Technical Reports Server (NTRS)

Vangenderen, J. L. (Principal Investigator)

1973-01-01

The author has identified the following significant results. The parallax on ERTS and Skylab images is sufficiently large for exploitation by human photointerpreters. The ability to view the imagery stereoscopically reduces the signal-to-noise ratio. Stereoscopic examination of orbital data can contribute to studies of spatial, spectral, and temporal variations on the imagery. The combination of true stereo parallax, plus shadow parallax offer many possibilities to human interpreters for making meaningful analyses of orbital imagery.

Virtual workstation - A multimodal, stereoscopic display environment

NASA Astrophysics Data System (ADS)

Fisher, S. S.; McGreevy, M.; Humphries, J.; Robinett, W.

1987-01-01

A head-mounted, wide-angle, stereoscopic display system controlled by operator position, voice and gesture has been developed for use in a multipurpose interface environment. The system provides a multisensory, interactive display environment in which a user can virtually explore a 360-degree synthesized or remotely sensed environment and can viscerally interact with its components. Primary applications of the system are in telerobotics, management of large-scale integrated information systems, and human factors research. System configuration, application scenarios, and research directions are described.

Digital stereoscopic cinema: the 21st century

NASA Astrophysics Data System (ADS)

Lipton, Lenny

2008-02-01

Over 1000 theaters in more than a dozen countries have been outfitted with digital projectors using the Texas Instruments DLP engine equipped to show field-sequential 3-D movies using the polarized method of image selection. Shuttering eyewear and advanced anaglyph products are also being deployed for image selection. Many studios are in production with stereoscopic films, and some have committed to producing their entire output of animated features in 3-D. This is a time of technology change for the motion picture industry.

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

Chifu, Iulia; Wiegelmann, Thomas; Inhester, Bernd, E-mail: chifu@mps.mpg.de

Insights into the 3D structure of the solar coronal magnetic field have been obtained in the past by two completely different approaches. The first approach are nonlinear force-free field (NLFFF) extrapolations, which use photospheric vector magnetograms as boundary condition. The second approach uses stereoscopy of coronal magnetic loops observed in EUV coronal images from different vantage points. Both approaches have their strengths and weaknesses. Extrapolation methods are sensitive to noise and inconsistencies in the boundary data, and the accuracy of stereoscopy is affected by the ability of identifying the same structure in different images and by the separation angle betweenmore » the view directions. As a consequence, for the same observational data, the 3D coronal magnetic fields computed with the two methods do not necessarily coincide. In an earlier work (Paper I) we extended our NLFFF optimization code by including stereoscopic constrains. The method was successfully tested with synthetic data, and within this work, we apply the newly developed code to a combined data set from SDO /HMI, SDO /AIA, and the two STEREO spacecraft. The extended method (called S-NLFFF) contains an additional term that monitors and minimizes the angle between the local magnetic field direction and the orientation of the 3D coronal loops reconstructed by stereoscopy. We find that when we prescribe the shape of the 3D stereoscopically reconstructed loops, the S-NLFFF method leads to a much better agreement between the modeled field and the stereoscopically reconstructed loops. We also find an appreciable decrease by a factor of two in the angle between the current and the magnetic field. This indicates the improved quality of the force-free solution obtained by S-NLFFF.« less

Nonlinear Force-free Coronal Magnetic Stereoscopy

NASA Astrophysics Data System (ADS)

Chifu, Iulia; Wiegelmann, Thomas; Inhester, Bernd

2017-03-01

Insights into the 3D structure of the solar coronal magnetic field have been obtained in the past by two completely different approaches. The first approach are nonlinear force-free field (NLFFF) extrapolations, which use photospheric vector magnetograms as boundary condition. The second approach uses stereoscopy of coronal magnetic loops observed in EUV coronal images from different vantage points. Both approaches have their strengths and weaknesses. Extrapolation methods are sensitive to noise and inconsistencies in the boundary data, and the accuracy of stereoscopy is affected by the ability of identifying the same structure in different images and by the separation angle between the view directions. As a consequence, for the same observational data, the 3D coronal magnetic fields computed with the two methods do not necessarily coincide. In an earlier work (Paper I) we extended our NLFFF optimization code by including stereoscopic constrains. The method was successfully tested with synthetic data, and within this work, we apply the newly developed code to a combined data set from SDO/HMI, SDO/AIA, and the two STEREO spacecraft. The extended method (called S-NLFFF) contains an additional term that monitors and minimizes the angle between the local magnetic field direction and the orientation of the 3D coronal loops reconstructed by stereoscopy. We find that when we prescribe the shape of the 3D stereoscopically reconstructed loops, the S-NLFFF method leads to a much better agreement between the modeled field and the stereoscopically reconstructed loops. We also find an appreciable decrease by a factor of two in the angle between the current and the magnetic field. This indicates the improved quality of the force-free solution obtained by S-NLFFF.

Sugarcane Crop Extraction Using Object-Oriented Method from ZY-3 High Resolution Satellite Tlc Image

NASA Astrophysics Data System (ADS)

Luo, H.; Ling, Z. Y.; Shao, G. Z.; Huang, Y.; He, Y. Q.; Ning, W. Y.; Zhong, Z.

2018-04-01

Sugarcane is one of the most important crops in Guangxi, China. As the development of satellite remote sensing technology, more remotely sensed images can be used for monitoring sugarcane crop. With the help of Three Line Camera (TLC) images, wide coverage and stereoscopic mapping ability, Chinese ZY-3 high resolution stereoscopic mapping satellite is useful in attaining more information for sugarcane crop monitoring, such as spectral, shape, texture difference between forward, nadir and backward images. Digital surface model (DSM) derived from ZY-3 TLC images are also able to provide height information for sugarcane crop. In this study, we make attempt to extract sugarcane crop from ZY-3 images, which are acquired in harvest period. Ortho-rectified TLC images, fused image, DSM are processed for our extraction. Then Object-oriented method is used in image segmentation, example collection, and feature extraction. The results of our study show that with the help of ZY-3 TLC image, the information of sugarcane crop in harvest time can be automatic extracted, with an overall accuracy of about 85.3 %.

Stereoscopic display technologies, interaction paradigms, and rendering approaches for neurosurgical visualization

NASA Astrophysics Data System (ADS)

Cooperstock, Jeremy R.; Wang, Guangyu

2009-02-01

We conducted a comparative study of different stereoscopic display modalities (head-mounted display, polarized projection, and multiview lenticular display) to evaluate their efficacy in supporting manipulation and understanding of 3D content, specifically, in the context of neurosurgical visualization. Our study was intended to quantify the differences in resulting task performance between these choices of display technology. The experimental configuration involved a segmented brain vasculature and a simulated tumor. Subjects were asked to manipulate the vasculature and a pen-like virtual probe in order to define a vessel-free path from cortical surface to the targeted tumor. Because of the anatomical complexity, defining such a path can be a challenging task. To evaluate the system, we quantified performance differences under three different stereoscopic viewing conditions. Our results indicate that, on average, participants achieved best performance using polarized projection, and worst with the multiview lenticular display. These quantitative measurements were further reinforced by the subjects' responses to our post-test questionnaire regarding personal preferences.

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

Sebok, A.; Nystad, E.

This paper describes a study investigating questions of learning effectiveness in different VR technology types. Four VR display technology types were compared in terms of their ability to support procedural learning. The VR systems included two desktop displays (mono-scopic and stereoscopic view), a large screen stereoscopic display, and a mono-scopic head-mounted display. Twenty-four participants completed procedural training scenarios on these different display types. Training effectiveness was assessed in terms of objective task performance. Following the training session, participants performed the procedure they had just learned using the same VR display type they used for training. Time to complete the proceduremore » and errors were recorded. Retention and transfer of training were evaluated in a talk-through session 24 hours after the training. In addition, subjective questionnaire data were gathered to investigate perceived workload, Sense of Presence, simulator sickness, perceived usability, and ease of navigation. While no difference was found for the short-term learning, the study results indicate that retention and transfer of training were better supported by the large screen stereoscopic condition. (authors)« less

Attack of the S. Mutans!: a stereoscopic-3D multiplayer direct-manipulation behavior-modification serious game for improving oral health in pre-teens

NASA Astrophysics Data System (ADS)

Hollander, Ari; Rose, Howard; Kollin, Joel; Moss, William

2011-03-01

Attack! of the S. Mutans is a multi-player game designed to harness the immersion and appeal possible with wide-fieldof- view stereoscopic 3D to combat the tooth decay epidemic. Tooth decay is one of the leading causes of school absences and costs more than $100B annually in the U.S. In 2008 the authors received a grant from the National Institutes of Health to build a science museum exhibit that included a suite of serious games involving the behaviors and bacteria that cause cavities. The centerpiece is an adventure game where five simultaneous players use modified Wii controllers to battle biofilms and bacteria while immersed in environments generated within a 11-foot stereoscopic WUXGA display. The authors describe the system and interface used in this prototype application and some of the ways they attempted to use the power of immersion and the appeal of S3D revolution to change health attitudes and self-care habits.

Stereoscopic 3D entertainment and its effect on viewing comfort: comparison of children and adults.

PubMed

Pölönen, Monika; Järvenpää, Toni; Bilcu, Beatrice

2013-01-01

Children's and adults' viewing comfort during stereoscopic three-dimensional film viewing and computer game playing was studied. Certain mild changes in visual function, heterophoria and near point of accommodation values, as well as eyestrain and visually induced motion sickness levels were found when single setups were compared. The viewing system had an influence on viewing comfort, in particular for eyestrain levels, but no clear difference between two- and three-dimensional systems was found. Additionally, certain mild changes in visual functions and visually induced motion sickness levels between adults and children were found. In general, all of the system-task combinations caused mild eyestrain and possible changes in visual functions, but these changes in magnitude were small. According to subjective opinions that further support these measurements, using a stereoscopic three-dimensional system for up to 2 h was acceptable for most of the users regardless of their age. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Surgical approaches to complex vascular lesions: the use of virtual reality and stereoscopic analysis as a tool for resident and student education.

PubMed

Agarwal, Nitin; Schmitt, Paul J; Sukul, Vishad; Prestigiacomo, Charles J

2012-08-01

Virtual reality training for complex tasks has been shown to be of benefit in fields involving highly technical and demanding skill sets. The use of a stereoscopic three-dimensional (3D) virtual reality environment to teach a patient-specific analysis of the microsurgical treatment modalities of a complex basilar aneurysm is presented. Three different surgical approaches were evaluated in a virtual environment and then compared to elucidate the best surgical approach. These approaches were assessed with regard to the line-of-sight, skull base anatomy and visualisation of the relevant anatomy at the level of the basilar artery and surrounding structures. Overall, the stereoscopic 3D virtual reality environment with fusion of multimodality imaging affords an excellent teaching tool for residents and medical students to learn surgical approaches to vascular lesions. Future studies will assess the educational benefits of this modality and develop a series of metrics for student assessments.

Three-Dimensional Stereoscopic Tracking Velocimetry and Experimental/Numerical Comparison of Directional Solidification

NASA Technical Reports Server (NTRS)

Lee, David; Ge, Yi; Cha, Soyoung Stephen; Ramachandran, Narayanan; Rose, M. Franklin (Technical Monitor)

2001-01-01

Measurement of three-dimensional (3-D) three-component velocity fields is of great importance in both ground and space experiments for understanding materials processing and fluid physics. The experiments in these fields most likely inhibit the application of conventional planar probes for observing 3-D phenomena. Here, we present the investigation results of stereoscopic tracking velocimetry (STV) for measuring 3-D velocity fields, which include diagnostic technology development, experimental velocity measurement, and comparison with analytical and numerical computation. STV is advantageous in system simplicity for building compact hardware and in software efficiency for continual near-real-time monitoring. It has great freedom in illuminating and observing volumetric fields from arbitrary directions. STV is based on stereoscopic observation of particles-Seeded in a flow by CCD sensors. In the approach, part of the individual particle images that provide data points is likely to be lost or cause errors when their images overlap and crisscross each other especially under a high particle density. In order to maximize the valid recovery of data points, neural networks are implemented for these two important processes. For the step of particle overlap decomposition, the back propagation neural network is utilized because of its ability in pattern recognition with pertinent particle image feature parameters. For the step of particle tracking, the Hopfield neural network is employed to find appropriate particle tracks based on global optimization. Our investigation indicates that the neural networks are very efficient and useful for stereoscopically tracking particles. As an initial assessment of the diagnostic technology performance, laminar water jets with and without pulsation are measured. The jet tip velocity profiles are in good agreement with analytical predictions. Finally, for testing in material processing applications, a simple directional solidification apparatus is built for experimenting with a metal analog of succinonitrile. Its 3-D velocity field at the liquid phase is then measured to be compared with those from numerical computation. Our theoretical, numerical, and experimental investigations have proven STV to be a viable candidate for reliably measuring 3-D flow velocities. With current activities are focused on further improving the processing efficiency, overall accuracy, and automation, the eventual efforts of broad experimental applications and concurrent numerical modeling validation will be vital to many areas in fluid flow and materials processing.

Experiments on shape perception in stereoscopic displays

NASA Astrophysics Data System (ADS)

Leroy, Laure; Fuchs, Philippe; Paljic, Alexis; Moreau, Guillaume

2009-02-01

Stereoscopic displays are increasingly used for computer-aided design. The aim is to make virtual prototypes to avoid building real ones, so that time, money and raw materials are saved. But do we really know whether virtual displays render the objects in a realistic way to potential users? In this study, we have performed several experiments in which we compare two virtual shapes to their equivalent in the real world, each of these aiming at a specific issue by a comparison: First, we performed some perception tests to evaluate the importance of head tracking to evaluate if it is better to concentrate our efforts on stereoscopic vision; Second, we have studied the effects of interpupillary distance; Third, we studied the effects of the position of the main object in comparison with the screen. Two different tests are used, the first one using a well-known shape (a sphere) and the second one using an irregular shape but with almost the same colour and dimension. These two tests allow us to determine if symmetry is important in their perception. We show that head tracking has a more important effect on shape perception than stereoscopic vision, especially on depth perception because the subject is able to move around the scene. The study also shows that an object between the subject and the screen is perceived better than an object which is on the screen, even if the latter is better for the eye strain.

Web GIS in practice VII: stereoscopic 3-D solutions for online maps and virtual globes

PubMed Central

Boulos, Maged N Kamel; Robinson, Larry R

2009-01-01

Because our pupils are about 6.5 cm apart, each eye views a scene from a different angle and sends a unique image to the visual cortex, which then merges the images from both eyes into a single picture. The slight difference between the right and left images allows the brain to properly perceive the 'third dimension' or depth in a scene (stereopsis). However, when a person views a conventional 2-D (two-dimensional) image representation of a 3-D (three-dimensional) scene on a conventional computer screen, each eye receives essentially the same information. Depth in such cases can only be approximately inferred from visual clues in the image, such as perspective, as only one image is offered to both eyes. The goal of stereoscopic 3-D displays is to project a slightly different image into each eye to achieve a much truer and realistic perception of depth, of different scene planes, and of object relief. This paper presents a brief review of a number of stereoscopic 3-D hardware and software solutions for creating and displaying online maps and virtual globes (such as Google Earth) in "true 3D", with costs ranging from almost free to multi-thousand pounds sterling. A practical account is also given of the experience of the USGS BRD UMESC (United States Geological Survey's Biological Resources Division, Upper Midwest Environmental Sciences Center) in setting up a low-cost, full-colour stereoscopic 3-D system. PMID:19849837

Cognitive responses and cortical oscillatory processing at various stereoscopic depths - a simultaneous EEG/MEG study.

PubMed

Cho, Hohyun; Kang, Min-Koo; Ahn, Sangtae; Kwon, Moonyoung; Yoon, Kuk-Jin; Kim, Kiwoong; Jun, Sung Chan

2017-01-01

Due to the recent explosion in various forms of 3D content, the evaluation of such content from a neuroscience perspective is quite interesting. However, existing investigations of cortical oscillatory responses in stereoscopic depth perception are quite rare. Therefore, we investigated spatiotemporal and spatio-temporo-spectral features at four different stereoscopic depths within the comfort zone. We adopted a simultaneous EEG/MEG acquisition technique to collect the oscillatory responses of eight participants. We defined subject-specific retinal disparities and designed a single trial-based stereoscopic viewing experimental paradigm. In the group analysis, we observed that, as the depth increased from Level 1 to Level 3, there was a time-locked increase in the N200 component in MEG and the P300 component in EEG in the occipital and parietal areas, respectively. In addition, initial alpha and beta event-related desynchronizations (ERD) were observed at approximately 500 to 1000 msec, while theta, alpha, and beta event-related synchronizations (ERS) appeared at approximately 1000 to 2000 ms. Interestingly, there was a saturation point in the increase in cognitive responses, including N200, P300, and alpha ERD, even when the depth increased only within the comfort zone. Meanwhile, the magnitude of low beta ERD decreased in the dorsal pathway as depth increased. From these findings, we concluded that cognitive responses are likely to become saturated in the visual comfort zone, while perceptual load may increase with depth.

Architecture for high performance stereoscopic game rendering on Android

NASA Astrophysics Data System (ADS)

Flack, Julien; Sanderson, Hugh; Shetty, Sampath

2014-03-01

Stereoscopic gaming is a popular source of content for consumer 3D display systems. There has been a significant shift in the gaming industry towards casual games for mobile devices running on the Android™ Operating System and driven by ARM™ and other low power processors. Such systems are now being integrated directly into the next generation of 3D TVs potentially removing the requirement for an external games console. Although native stereo support has been integrated into some high profile titles on established platforms like Windows PC and PS3 there is a lack of GPU independent 3D support for the emerging Android platform. We describe a framework for enabling stereoscopic 3D gaming on Android for applications on mobile devices, set top boxes and TVs. A core component of the architecture is a 3D game driver, which is integrated into the Android OpenGL™ ES graphics stack to convert existing 2D graphics applications into stereoscopic 3D in real-time. The architecture includes a method of analyzing 2D games and using rule based Artificial Intelligence (AI) to position separate objects in 3D space. We describe an innovative stereo 3D rendering technique to separate the views in the depth domain and render directly into the display buffer. The advantages of the stereo renderer are demonstrated by characterizing the performance in comparison to more traditional render techniques, including depth based image rendering, both in terms of frame rates and impact on battery consumption.

Web GIS in practice VII: stereoscopic 3-D solutions for online maps and virtual globes.

PubMed

Boulos, Maged N Kamel; Robinson, Larry R

2009-10-22

Because our pupils are about 6.5 cm apart, each eye views a scene from a different angle and sends a unique image to the visual cortex, which then merges the images from both eyes into a single picture. The slight difference between the right and left images allows the brain to properly perceive the 'third dimension' or depth in a scene (stereopsis). However, when a person views a conventional 2-D (two-dimensional) image representation of a 3-D (three-dimensional) scene on a conventional computer screen, each eye receives essentially the same information. Depth in such cases can only be approximately inferred from visual clues in the image, such as perspective, as only one image is offered to both eyes. The goal of stereoscopic 3-D displays is to project a slightly different image into each eye to achieve a much truer and realistic perception of depth, of different scene planes, and of object relief. This paper presents a brief review of a number of stereoscopic 3-D hardware and software solutions for creating and displaying online maps and virtual globes (such as Google Earth) in "true 3D", with costs ranging from almost free to multi-thousand pounds sterling. A practical account is also given of the experience of the USGS BRD UMESC (United States Geological Survey's Biological Resources Division, Upper Midwest Environmental Sciences Center) in setting up a low-cost, full-colour stereoscopic 3-D system.

Web GIS in practice VII: stereoscopic 3-D solutions for online maps and virtual globes

USGS Publications Warehouse

Boulos, Maged N.K.; Robinson, Larry R.

2009-01-01

Because our pupils are about 6.5 cm apart, each eye views a scene from a different angle and sends a unique image to the visual cortex, which then merges the images from both eyes into a single picture. The slight difference between the right and left images allows the brain to properly perceive the 'third dimension' or depth in a scene (stereopsis). However, when a person views a conventional 2-D (two-dimensional) image representation of a 3-D (three-dimensional) scene on a conventional computer screen, each eye receives essentially the same information. Depth in such cases can only be approximately inferred from visual clues in the image, such as perspective, as only one image is offered to both eyes. The goal of stereoscopic 3-D displays is to project a slightly different image into each eye to achieve a much truer and realistic perception of depth, of different scene planes, and of object relief. This paper presents a brief review of a number of stereoscopic 3-D hardware and software solutions for creating and displaying online maps and virtual globes (such as Google Earth) in "true 3D", with costs ranging from almost free to multi-thousand pounds sterling. A practical account is also given of the experience of the USGS BRD UMESC (United States Geological Survey's Biological Resources Division, Upper Midwest Environmental Sciences Center) in setting up a low-cost, full-colour stereoscopic 3-D system.

Modeling of a 3DTV service in the software-defined networking architecture

NASA Astrophysics Data System (ADS)

Wilczewski, Grzegorz

2014-11-01

In this article a newly developed concept towards modeling of a multimedia service offering stereoscopic motion imagery is presented. Proposed model is based on the approach of utilization of Software-defined Networking or Software Defined Networks architecture (SDN). The definition of 3D television service spanning SDN concept is identified, exposing basic characteristic of a 3DTV service in a modern networking organization layout. Furthermore, exemplary functionalities of the proposed 3DTV model are depicted. It is indicated that modeling of a 3DTV service in the Software-defined Networking architecture leads to multiplicity of improvements, especially towards flexibility of a service supporting heterogeneity of end user devices.

A compact high-definition low-cost digital stereoscopic video camera for rapid robotic surgery development.

PubMed

Carlson, Jay; Kowalczuk, Jędrzej; Psota, Eric; Pérez, Lance C

2012-01-01

Robotic surgical platforms require vision feedback systems, which often consist of low-resolution, expensive, single-imager analog cameras. These systems are retooled for 3D display by simply doubling the cameras and outboard control units. Here, a fully-integrated digital stereoscopic video camera employing high-definition sensors and a class-compliant USB video interface is presented. This system can be used with low-cost PC hardware and consumer-level 3D displays for tele-medical surgical applications including military medical support, disaster relief, and space exploration.

Using a high-definition stereoscopic video system to teach microscopic surgery

NASA Astrophysics Data System (ADS)

Ilgner, Justus; Park, Jonas Jae-Hyun; Labbé, Daniel; Westhofen, Martin

2007-02-01

Introduction: While there is an increasing demand for minimally invasive operative techniques in Ear, Nose and Throat surgery, these operations are difficult to learn for junior doctors and demanding to supervise for experienced surgeons. The motivation for this study was to integrate high-definition (HD) stereoscopic video monitoring in microscopic surgery in order to facilitate teaching interaction between senior and junior surgeon. Material and methods: We attached a 1280x1024 HD stereo camera (TrueVisionSystems TM Inc., Santa Barbara, CA, USA) to an operating microscope (Zeiss ProMagis, Zeiss Co., Oberkochen, Germany), whose images were processed online by a PC workstation consisting of a dual Intel® Xeon® CPU (Intel Co., Santa Clara, CA). The live image was displayed by two LCD projectors @ 1280x768 pixels on a 1,25m rear-projection screen by polarized filters. While the junior surgeon performed the surgical procedure based on the displayed stereoscopic image, all other participants (senior surgeon, nurse and medical students) shared the same stereoscopic image from the screen. Results: With the basic setup being performed only once on the day before surgery, fine adjustments required about 10 minutes extra during the operation schedule, which fitted into the time interval between patients and thus did not prolong operation times. As all relevant features of the operative field were demonstrated on one large screen, four major effects were obtained: A) Stereoscopy facilitated orientation for the junior surgeon as well as for medical students. B) The stereoscopic image served as an unequivocal guide for the senior surgeon to demonstrate the next surgical steps to the junior colleague. C) The theatre nurse shared the same image, anticipating the next instruments which were needed. D) Medical students instantly share the information given by all staff and the image, thus avoiding the need for an extra teaching session. Conclusion: High definition stereoscopy bears the potential to compress the learning curve for undergraduate as well as postgraduate medical professionals in minimally invasive surgery. Further studies will focus on the long term effect for operative training as well as on post-processing of HD stereoscopy video content for off-line interactive medical education.

Parallel-Processing Software for Correlating Stereo Images

NASA Technical Reports Server (NTRS)

Klimeck, Gerhard; Deen, Robert; Mcauley, Michael; DeJong, Eric

2007-01-01

A computer program implements parallel- processing algorithms for cor relating images of terrain acquired by stereoscopic pairs of digital stereo cameras on an exploratory robotic vehicle (e.g., a Mars rove r). Such correlations are used to create three-dimensional computatio nal models of the terrain for navigation. In this program, the scene viewed by the cameras is segmented into subimages. Each subimage is assigned to one of a number of central processing units (CPUs) opera ting simultaneously.

A strategy for mineral and energy resource independence

USGS Publications Warehouse

Carter, W.D.

1983-01-01

Data acquired by Landsats 1, 2, and 3, are beginning to provide the information on which an improved mineral and energy resource exploration strategy can be based. Landsat 4 is expected to augment this capability with its higher resolution (30 m) and additional spectral bands in the Thematic Mapper (TM) designed specifically to discriminate clay minerals associated with mineral alteration. In addition, a new global magnetic anomaly map, derived from the recent Magsat mission, has recently been compiled by the National Aeronautics and Space Administration (NASA), the U.S. Geological Survey (USGS), and others. Preliminary, extremely small-scale renditions of this map indicate that global coverage is nearly complete and that the map will improve upon a previous one derived from Polar Orbiting Geophysical Observatory (POGO) data. Digital processing of the Landsat image data and Magsat geophysical data can be used to create three-dimensional stereoscopic models for which Landsat images provide surface reference to deep structural anomalies. Comparative studies of national Landsat lineament maps, Magsat stereoscopic models, and metallogenic information derived from the Computerized Resources Information Bank (CRIB) inventory of U.S. mineral resources, provide a way of identifying and selecting exploration areas that have mineral resource potential. Landsat images and computer-compatible tapes can provide new and better mosaics and also provide the capability for a closer look at promising sites. ?? 1983.

Experimental investigations of pupil accommodation factors.

PubMed

Lee, Eui Chul; Lee, Ji Woo; Park, Kang Ryoung

2011-08-17

PURPOSE. The contraction and dilation of the iris muscle that controls the amount of light entering the retina causes pupil accommodation. In this study, experiments were performed and two of the three factors that influence pupil accommodation were analyzed: lighting conditions and depth fixations. The psychological benefits were not examined, because they could not be quantified. METHODS. A head-wearable eyeglasses-based, eye-capturing device was designed to measure pupil size. It included a near-infrared (NIR) camera and an NIR light-emitting diode. Twenty-four subjects watched two-dimensional (2D) and three-dimensional (3D) stereoscopic videos of the same content, and the changes in pupil size were measured by using the eye-capturing device and image-processing methods: RESULTS. The pupil size changed with the intensity of the videos and the disparities between the left and right images of a 3D stereoscopic video. There was correlation between the pupil size and average intensity. The pupil diameter could be estimated as being contracted from approximately 5.96 to 4.25 mm as the intensity varied from 0 to 255. Further, from the changes in the depth fixation for the pupil accommodation, it was confirmed that the depth fixation also affected accommodation of pupil size. CONCLUSIONS. It was confirmed that the lighting condition was an even more significant factor in pupil accommodation than was depth fixation (significance ratio: approximately 3.2:1) when watching 3D stereoscopic video. Pupil accommodation was more affected by depth fixation in the real world than was the binocular convergence in the 3D stereoscopic display.

Study of high-definition and stereoscopic head-aimed vision for improved teleoperation of an unmanned ground vehicle

NASA Astrophysics Data System (ADS)

Tyczka, Dale R.; Wright, Robert; Janiszewski, Brian; Chatten, Martha Jane; Bowen, Thomas A.; Skibba, Brian

2012-06-01

Nearly all explosive ordnance disposal robots in use today employ monoscopic standard-definition video cameras to relay live imagery from the robot to the operator. With this approach, operators must rely on shadows and other monoscopic depth cues in order to judge distances and object depths. Alternatively, they can contact an object with the robot's manipulator to determine its position, but that approach carries with it the risk of detonation from unintentionally disturbing the target or nearby objects. We recently completed a study in which high-definition (HD) and stereoscopic video cameras were used in addition to conventional standard-definition (SD) cameras in order to determine if higher resolutions and/or stereoscopic depth cues improve operators' overall performance of various unmanned ground vehicle (UGV) tasks. We also studied the effect that the different vision modes had on operator comfort. A total of six different head-aimed vision modes were used including normal-separation HD stereo, SD stereo, "micro" (reduced separation) SD stereo, HD mono, and SD mono (two types). In general, the study results support the expectation that higher resolution and stereoscopic vision aid UGV teleoperation, but the degree of improvement was found to depend on the specific task being performed; certain tasks derived notably more benefit from improved depth perception than others. This effort was sponsored by the Joint Ground Robotics Enterprise under Robotics Technology Consortium Agreement #69-200902 T01. Technical management was provided by the U.S. Air Force Research Laboratory's Robotics Research and Development Group at Tyndall AFB, Florida.

Parallax scanning methods for stereoscopic three-dimensional imaging

NASA Astrophysics Data System (ADS)

Mayhew, Christopher A.; Mayhew, Craig M.

2012-03-01

Under certain circumstances, conventional stereoscopic imagery is subject to being misinterpreted. Stereo perception created from two static horizontally separated views can create a "cut out" 2D appearance for objects at various planes of depth. The subject volume looks three-dimensional, but the objects themselves appear flat. This is especially true if the images are captured using small disparities. One potential explanation for this effect is that, although three-dimensional perception comes primarily from binocular vision, a human's gaze (the direction and orientation of a person's eyes with respect to their environment) and head motion also contribute additional sub-process information. The absence of this information may be the reason that certain stereoscopic imagery appears "odd" and unrealistic. Another contributing factor may be the absence of vertical disparity information in a traditional stereoscopy display. Recently, Parallax Scanning technologies have been introduced, which provide (1) a scanning methodology, (2) incorporate vertical disparity, and (3) produce stereo images with substantially smaller disparities than the human interocular distances.1 To test whether these three features would improve the realism and reduce the cardboard cutout effect of stereo images, we have applied Parallax Scanning (PS) technologies to commercial stereoscopic digital cinema productions and have tested the results with a panel of stereo experts. These informal experiments show that the addition of PS information into the left and right image capture improves the overall perception of three-dimensionality for most viewers. Parallax scanning significantly increases the set of tools available for 3D storytelling while at the same time presenting imagery that is easy and pleasant to view.

Comparison between infrared optical and stereoscopic X-ray technologies for patient setup in image guided stereotactic radiotherapy.

PubMed

Tagaste, Barbara; Riboldi, Marco; Spadea, Maria F; Bellante, Simone; Baroni, Guido; Cambria, Raffaella; Garibaldi, Cristina; Ciocca, Mario; Catalano, Gianpiero; Alterio, Daniela; Orecchia, Roberto

2012-04-01

To compare infrared (IR) optical vs. stereoscopic X-ray technologies for patient setup in image-guided stereotactic radiotherapy. Retrospective data analysis of 233 fractions in 127 patients treated with hypofractionated stereotactic radiotherapy was performed. Patient setup at the linear accelerator was carried out by means of combined IR optical localization and stereoscopic X-ray image fusion in 6 degrees of freedom (6D). Data were analyzed to evaluate the geometric and dosimetric discrepancy between the two patient setup strategies. Differences between IR optical localization and 6D X-ray image fusion parameters were on average within the expected localization accuracy, as limited by CT image resolution (3 mm). A disagreement between the two systems below 1 mm in all directions was measured in patients treated for cranial tumors. In extracranial sites, larger discrepancies and higher variability were observed as a function of the initial patient alignment. The compensation of IR-detected rotational errors resulted in a significantly improved agreement with 6D X-ray image fusion. On the basis of the bony anatomy registrations, the measured differences were found not to be sensitive to patient breathing. The related dosimetric analysis showed that IR-based patient setup caused limited variations in three cases, with 7% maximum dose reduction in the clinical target volume and no dose increase in organs at risk. In conclusion, patient setup driven by IR external surrogates localization in 6D featured comparable accuracy with respect to procedures based on stereoscopic X-ray imaging. Copyright © 2012 Elsevier Inc. All rights reserved.

Optical cross-talk and visual comfort of a stereoscopic display used in a real-time application

NASA Astrophysics Data System (ADS)

Pala, S.; Stevens, R.; Surman, P.

2007-02-01

Many 3D systems work by presenting to the observer stereoscopic pairs of images that are combined to give the impression of a 3D image. Discomfort experienced when viewing for extended periods may be due to several factors, including the presence of optical crosstalk between the stereo image channels. In this paper we use two video cameras and two LCD panels viewed via a Helmholtz arrangement of mirrors, to display a stereoscopic image inherently free of crosstalk. Simple depth discrimination tasks are performed whilst viewing the 3D image and controlled amounts of image crosstalk are introduced by electronically mixing the video signals. Error monitoring and skin conductance are used as measures of workload as well as traditional subjective questionnaires. We report qualitative measurements of user workload under a variety of viewing conditions. This pilot study revealed a decrease in task performance and increased workload as crosstalk was increased. The observations will assist in the design of further trials planned to be conducted in a medical environment.

Visual discomfort in stereoscopic displays: a review

NASA Astrophysics Data System (ADS)

Lambooij, Marc T. M.; IJsselsteijn, Wijnand A.; Heynderickx, Ingrid

2007-02-01

Visual discomfort has been the subject of considerable research in relation to stereoscopic and autostereoscopic displays, but remains an ambiguous concept used to denote a variety of subjective symptoms potentially related to different underlying processes. In this paper we clarify the importance of various causes and aspects of visual comfort. Classical causative factors such as excessive binocular parallax and accommodation-convergence conflict appear to be of minor importance when disparity values do not surpass one degree limit of visual angle, which still provides sufficient range to allow for satisfactory depth perception in consumer applications, such as stereoscopic television. Visual discomfort, however, may still occur within this limit and we believe the following factors to be the most pertinent in contributing to this: (1) excessive demand of accommodation-convergence linkage, e.g., by fast motion in depth, viewed at short distances, (2) 3D artefacts resulting from insufficient depth information in the incoming data signal yielding spatial and temporal inconsistencies, and (3) unnatural amounts of blur. In order to adequately characterize and understand visual discomfort, multiple types of measurements, both objective and subjective, are needed.

Figure and Ground in the Visual Cortex: V2 Combines Stereoscopic Cues with Gestalt Rules

PubMed Central

Qiu, Fangtu T.; von der Heydt, Rüdiger

2006-01-01

Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring three-dimensional (3D) layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border-ownership coding). Here we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (gestalt factors). These are combined in single neurons so that the ‘near’ side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays gestalt factors influence the responses and can enhance or null the stereoscopic depth information. PMID:15996555

Subjective evaluation of two stereoscopic imaging systems exploiting visual attention to improve 3D quality of experience

NASA Astrophysics Data System (ADS)

Hanhart, Philippe; Ebrahimi, Touradj

2014-03-01

Crosstalk and vergence-accommodation rivalry negatively impact the quality of experience (QoE) provided by stereoscopic displays. However, exploiting visual attention and adapting the 3D rendering process on the fly can reduce these drawbacks. In this paper, we propose and evaluate two different approaches that exploit visual attention to improve 3D QoE on stereoscopic displays: an offline system, which uses a saliency map to predict gaze position, and an online system, which uses a remote eye tracking system to measure real time gaze positions. The gaze points were used in conjunction with the disparity map to extract the disparity of the object-of-interest. Horizontal image translation was performed to bring the fixated object on the screen plane. The user preference between standard 3D mode and the two proposed systems was evaluated through a subjective evaluation. Results show that exploiting visual attention significantly improves image quality and visual comfort, with a slight advantage for real time gaze determination. Depth quality is also improved, but the difference is not significant.

Extending the Life of Virtual Heritage: Reuse of Tls Point Clouds in Synthetic Stereoscopic Spherical Images

NASA Astrophysics Data System (ADS)

Garcia Fernandez, J.; Tammi, K.; Joutsiniemi, A.

2017-02-01

Recent advances in Terrestrial Laser Scanner (TLS), in terms of cost and flexibility, have consolidated this technology as an essential tool for the documentation and digitalization of Cultural Heritage. However, once the TLS data is used, it basically remains stored and left to waste.How can highly accurate and dense point clouds (of the built heritage) be processed for its reuse, especially to engage a broader audience? This paper aims to answer this question by a channel that minimizes the need for expert knowledge, while enhancing the interactivity with the as-built digital data: Virtual Heritage Dissemination through the production of VR content. Driven by the ProDigiOUs project's guidelines on data dissemination (EU funded), this paper advances in a production path to transform the point cloud into virtual stereoscopic spherical images, taking into account the different visual features that produce depth perception, and especially those prompting visual fatigue while experiencing the VR content. Finally, we present the results of the Hiedanranta's scans transformed into stereoscopic spherical animations.

Calculation of 3D Coordinates of a Point on the Basis of a Stereoscopic System

NASA Astrophysics Data System (ADS)

Mussabayev, R. R.; Kalimoldayev, M. N.; Amirgaliyev, Ye. N.; Tairova, A. T.; Mussabayev, T. R.

2018-05-01

The solution of three-dimensional (3D) coordinate calculation task for a material point is considered. Two flat images (a stereopair) which correspond to the left and to the right viewpoints of a 3D scene are used for this purpose. The stereopair is obtained using two cameras with parallel optical axes. The analytical formulas for calculating 3D coordinates of a material point in the scene were obtained on the basis of analysis of the stereoscopic system optical and geometrical schemes. The detailed presentation of the algorithmic and hardware realization of the given method was discussed with the the practical. The practical module was recommended for the determination of the optical system unknown parameters. The series of experimental investigations were conducted for verification of theoretical results. During these experiments the minor inaccuracies were occurred by space distortions in the optical system and by it discrecity. While using the high quality stereoscopic system, the existing calculation inaccuracy enables to apply the given method for the wide range of practical tasks.

Figure and ground in the visual cortex: v2 combines stereoscopic cues with gestalt rules.

PubMed

Qiu, Fangtu T; von der Heydt, Rüdiger

2005-07-07

Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring 3D layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border ownership coding). Here, we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (Gestalt factors). These are combined in single neurons so that the "near" side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays, Gestalt factors influence the responses and can enhance or null the stereoscopic depth information.

A virtual reality oriented clinical experiment on post-stroke rehabilitation: performance and preference comparison among different stereoscopic displays­

NASA Astrophysics Data System (ADS)

Yeh, Shih-Ching; Rizzo, Albert; Sawchuk, Alexander A.

2007-02-01

We have developed a novel VR task: the Dynamic Reaching Test, that measures human forearm movement in 3D space. In this task, three different stereoscopic displays: autostereoscopic (AS), shutter glasses (SG) and head mounted display (HMD), are used in tests in which subjects must catch a virtual ball thrown at them. Parameters such as percentage of successful catches, movement efficiency (subject path length compared to minimal path length), and reaction time are measured to evaluate differences in 3D perception among the three stereoscopic displays. The SG produces the highest percentage of successful catches, though the difference between the three displays is small, implying that users can perform the VR task with any of the displays. The SG and HMD produced the best movement efficiency, while the AS was slightly less efficient. Finally, the AS and HMD produced similar reaction times that were slightly higher (by 0.1 s) than the SG. We conclude that SG and HMD displays were the most effective, but only slightly better than the AS display.

Real-time photorealistic stereoscopic rendering of fire

NASA Astrophysics Data System (ADS)

Rose, Benjamin M.; McAllister, David F.

2007-02-01

We propose a method for real-time photorealistic stereo rendering of the natural phenomenon of fire. Applications include the use of virtual reality in fire fighting, military training, and entertainment. Rendering fire in real-time presents a challenge because of the transparency and non-static fluid-like behavior of fire. It is well known that, in general, methods that are effective for monoscopic rendering are not necessarily easily extended to stereo rendering because monoscopic methods often do not provide the depth information necessary to produce the parallax required for binocular disparity in stereoscopic rendering. We investigate the existing techniques used for monoscopic rendering of fire and discuss their suitability for extension to real-time stereo rendering. Methods include the use of precomputed textures, dynamic generation of textures, and rendering models resulting from the approximation of solutions of fluid dynamics equations through the use of ray-tracing algorithms. We have found that in order to attain real-time frame rates, our method based on billboarding is effective. Slicing is used to simulate depth. Texture mapping or 2D images are mapped onto polygons and alpha blending is used to treat transparency. We can use video recordings or prerendered high-quality images of fire as textures to attain photorealistic stereo.

Disparity modification in stereoscopic images for emotional enhancement

NASA Astrophysics Data System (ADS)

Kawai, Takashi; Atsuta, Daiki; Kim, Sanghyun; Häkkinen, Jukka

2015-03-01

This paper describes an experiment that focuses on disparity changes in emotional scenes of stereoscopic (3D) images, in which an examination of the effects on pleasant and arousal was carried out by adding binocular disparity to 2D images that evoke specific emotions, and applying disparity modification based on the disparity analysis of prominent 3D movies. From the results of the experiment, it was found that pleasant and arousal was increased by expanding 3D space to a certain level. In addition, pleasant gradually decreased and arousal gradually increased by expansion of 3D space above a certain level.

Device for diagnosis and treatment of impairments on binocular vision and stereopsis

NASA Astrophysics Data System (ADS)

Bahn, Jieun; Choi, Yong-Jin; Son, Jung-Young; Kodratiev, N. V.; Elkhov, Victor A.; Ovechkis, Yuri N.; Chung, Chan-sup

2001-06-01

Strabismus and amblyopia are two main impairments of our visual system, which are responsible for the loss of stereovision. A device is developed for diagnosis and treatment of strabismus and amblyopia, and for training and developing stereopsis. This device is composed of a liquid crystal glasses (LCG), electronics for driving LCG and synchronizing with an IBM PC, and a special software. The software contains specially designed patterns and graphics for enabling to train and develop stereopsis, and do objective measurement of some stereoscopic vision parameters such as horizontal and vertical phoria, fusion, fixation disparity, and stereoscopic visual threshold.

Stereoscopic display technologies for FHD 3D LCD TV

NASA Astrophysics Data System (ADS)

Kim, Dae-Sik; Ko, Young-Ji; Park, Sang-Moo; Jung, Jong-Hoon; Shestak, Sergey

2010-04-01

Stereoscopic display technologies have been developed as one of advanced displays, and many TV industrials have been trying commercialization of 3D TV. We have been developing 3D TV based on LCD with LED BLU (backlight unit) since Samsung launched the world's first 3D TV based on PDP. However, the data scanning of panel and LC's response characteristics of LCD TV cause interference among frames (that is crosstalk), and this makes 3D video quality worse. We propose the method to reduce crosstalk by LCD driving and backlight control of FHD 3D LCD TV.

Optimizing dual-energy x-ray parameters for the ExacTrac clinical stereoscopic imaging system to enhance soft-tissue imaging.

PubMed

Bowman, Wesley A; Robar, James L; Sattarivand, Mike

2017-03-01

Stereoscopic x-ray image guided radiotherapy for lung tumors is often hindered by bone overlap and limited soft-tissue contrast. This study aims to evaluate the feasibility of dual-energy imaging techniques and to optimize parameters of the ExacTrac stereoscopic imaging system to enhance soft-tissue imaging for application to lung stereotactic body radiation therapy. Simulated spectra and a physical lung phantom were used to optimize filter material, thickness, tube potentials, and weighting factors to obtain bone subtracted dual-energy images. Spektr simulations were used to identify material in the atomic number range (3-83) based on a metric defined to separate spectra of high and low-energies. Both energies used the same filter due to time constraints of imaging in the presence of respiratory motion. The lung phantom contained bone, soft tissue, and tumor mimicking materials, and it was imaged with a filter thickness in the range of (0-0.7) mm and a kVp range of (60-80) for low energy and (120,140) for high energy. Optimal dual-energy weighting factors were obtained when the bone to soft-tissue contrast-to-noise ratio (CNR) was minimized. Optimal filter thickness and tube potential were achieved by maximizing tumor-to-background CNR. Using the optimized parameters, dual-energy images of an anthropomorphic Rando phantom with a spherical tumor mimicking material inserted in his lung were acquired and evaluated for bone subtraction and tumor contrast. Imaging dose was measured using the dual-energy technique with and without beam filtration and matched to that of a clinical conventional single energy technique. Tin was the material of choice for beam filtering providing the best energy separation, non-toxicity, and non-reactiveness. The best soft-tissue-weighted image in the lung phantom was obtained using 0.2 mm tin and (140, 60) kVp pair. Dual-energy images of the Rando phantom with the tin filter had noticeable improvement in bone elimination, tumor contrast, and noise content when compared to dual-energy imaging with no filtration. The surface dose was 0.52 mGy per each stereoscopic view for both clinical single energy technique and the dual-energy technique in both cases of with and without the tin filter. Dual-energy soft-tissue imaging is feasible without additional imaging dose using the ExacTrac stereoscopic imaging system with optimized acquisition parameters and no beam filtration. Addition of a single tin filter for both the high and low energies has noticeable improvements on dual-energy imaging with optimized parameters. Clinical implementation of a dual-energy technique on ExacTrac stereoscopic imaging could improve lung tumor visibility. © 2017 American Association of Physicists in Medicine.

Expeditious illustration of layer-cake models on and above a tactile surface

NASA Astrophysics Data System (ADS)

Lopes, Daniel Simões; Mendes, Daniel; Sousa, Maurício; Jorge, Joaquim

2016-05-01

Too often illustrating and visualizing 3D geological concepts are performed by sketching in 2D mediums, which may limit drawing performance of initial concepts. Here, the potential of expeditious geological modeling brought by hand gestures is explored. A spatial interaction system was developed to enable rapid modeling, editing, and exploration of 3D layer-cake objects. User interactions are acquired with motion capture and touch screen technologies. Virtual immersion is guaranteed by using stereoscopic technology. The novelty consists of performing expeditious modeling of coarse geological features with only a limited set of hand gestures. Results from usability-studies show that the proposed system is more efficient when compared to a windows-icon-menu-pointer modeling application.

SPHERES Vertigo

NASA Image and Video Library

2014-07-25

ISS040-E-079083 (25 July 2014) --- In the International Space Station?s Kibo laboratory, NASA astronaut Steve Swanson, Expedition 40 commander, enters data in a computer in preparation for a session with a trio of soccer-ball-sized robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The free-flying robots were equipped with stereoscopic goggles called the Visual Estimation and Relative Tracking for Inspection of Generic Objects, or VERTIGO, to enable the SPHERES to perform relative navigation based on a 3D model of a target object.

SPHERES-Vertigo experiment

NASA Image and Video Library

2014-07-25

ISS040-E-080130 (25 July 2014) --- In the International Space Station?s Kibo laboratory, European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, conducts a session with a trio of soccer-ball-sized robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The free-flying robots were equipped with stereoscopic goggles called the Visual Estimation and Relative Tracking for Inspection of Generic Objects, or VERTIGO, to enable the SPHERES to perform relative navigation based on a 3D model of a target object.

Optimal combination of illusory and luminance-defined 3-D surfaces: A role for ambiguity.

PubMed

Hartle, Brittney; Wilcox, Laurie M; Murray, Richard F

2018-04-01

The shape of the illusory surface in stereoscopic Kanizsa figures is determined by the interpolation of depth from the luminance edges of adjacent inducing elements. Despite ambiguity in the position of illusory boundaries, observers reliably perceive a coherent three-dimensional (3-D) surface. However, this ambiguity may contribute additional uncertainty to the depth percept beyond what is expected from measurement noise alone. We evaluated the intrinsic ambiguity of illusory boundaries by using a cue-combination paradigm to measure the reliability of depth percepts elicited by stereoscopic illusory surfaces. We assessed the accuracy and precision of depth percepts using 3-D Kanizsa figures relative to luminance-defined surfaces. The location of the surface peak was defined by illusory boundaries, luminance-defined edges, or both. Accuracy and precision were assessed using a depth-discrimination paradigm. A maximum likelihood linear cue combination model was used to evaluate the relative contribution of illusory and luminance-defined signals to the perceived depth of the combined surface. Our analysis showed that the standard deviation of depth estimates was consistent with an optimal cue combination model, but the points of subjective equality indicated that observers consistently underweighted the contribution of illusory boundaries. This systematic underweighting may reflect a combination rule that attributes additional intrinsic ambiguity to the location of the illusory boundary. Although previous studies show that illusory and luminance-defined contours share many perceptual similarities, our model suggests that ambiguity plays a larger role in the perceptual representation of illusory contours than of luminance-defined contours.

Inter-Comparison of WRF Model Simulated Winds and MISR Stereoscopic Winds Embedded within Mesoscale von Kármán Wake Vortices

NASA Astrophysics Data System (ADS)

Horvath, A.; Nunalee, C. G.; Mueller, K. J.

2014-12-01

Several distinct wake regimes are possible when considering atmospheric flow past a steep mountainous island. Of these regimes, coherent vortex shedding in low-Froude number flow is particularly interesting because it can produce laterally focused paths of counter rotating eddies capable of extending downstream for hundreds of kilometers (i.e., a von Kármán vortex street). Given the spatial scales of atmospheric von Kármán vortices, which typically lies on the interface of the meso-scale and the micro-scale, they are uniquely challenging to model using conventional numerical weather prediction platforms. In this presentation, we present high resolution (1-km horizontally) numerical modeling results using the Weather Research and Forecasting (WRF) model, of multiple real-world von Kármán vortex shedding events associated with steep islands (e.g., Madeira island, Gran Canaria island, etc.). In parallel, we also present corresponding cloud-motion wind and cloud-top height measurements from the satellite-based Multiangle Imaging SpectroRadiometer (MISR) instrument. The MISR stereo algorithm enables experimental retrieval of the horizontal wind vector (both along-track and cross-track components) at 4.4-km resolution, in addition to the operational 1.1-km resolution cross-track wind and cloud-top height products. These products offer the fidelity appropriate for inter-comparison with the numerically simulated vortex streets. In general, we find an agreement between the instantaneous simulated cloud level winds and the MISR stereoscopic winds; however, discrepancies in the vortex street length and localized horizontal wind shear were documented. In addition, the simulated fields demonstrate sensitivity to turbulence closure and input terrain height data.

Effect of image scaling on stereoscopic movie experience

NASA Astrophysics Data System (ADS)

Häkkinen, Jukka P.; Hakala, Jussi; Hannuksela, Miska; Oittinen, Pirkko

2011-03-01

Camera separation affects the perceived depth in stereoscopic movies. Through control of the separation and thereby the depth magnitudes, the movie can be kept comfortable but interesting. In addition, the viewing context has a significant effect on the perceived depth, as a larger display and longer viewing distances also contribute to an increase in depth. Thus, if the content is to be viewed in multiple viewing contexts, the depth magnitudes should be carefully planned so that the content always looks acceptable. Alternatively, the content can be modified for each viewing situation. To identify the significance of changes due to the viewing context, we studied the effect of stereoscopic camera base distance on the viewer experience in three different situations: 1) small sized video and a viewing distance of 38 cm, 2) television and a viewing distance of 158 cm, and 3) cinema and a viewing distance of 6-19 meters. We examined three different animations with positive parallax. The results showed that the camera distance had a significant effect on the viewing experience in small display/short viewing distance situations, in which the experience ratings increased until the maximum disparity in the scene was 0.34 - 0.45 degrees of visual angle. After 0.45 degrees, increasing the depth magnitude did not affect the experienced quality ratings. Interestingly, changes in the camera distance did not affect the experience ratings in the case of television or cinema if the depth magnitudes were below one degree of visual angle. When the depth was greater than one degree, the experience ratings began to drop significantly. These results indicate that depth magnitudes have a larger effect on the viewing experience with a small display. When a stereoscopic movie is viewed from a larger display, other experiences might override the effect of depth magnitudes.

ESTABLISHING A STEREOSCOPIC TECHNIQUE FOR DETERMINING THE KINEMATIC PROPERTIES OF SOLAR WIND TRANSIENTS BASED ON A GENERALIZED SELF-SIMILARLY EXPANDING CIRCULAR GEOMETRY

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

Davies, J. A.; Perry, C. H.; Harrison, R. A.

2013-11-10

The twin-spacecraft STEREO mission has enabled simultaneous white-light imaging of the solar corona and inner heliosphere from multiple vantage points. This has led to the development of numerous stereoscopic techniques to investigate the three-dimensional structure and kinematics of solar wind transients such as coronal mass ejections (CMEs). Two such methods—triangulation and the tangent to a sphere—can be used to determine time profiles of the propagation direction and radial distance (and thereby radial speed) of a solar wind transient as it travels through the inner heliosphere, based on its time-elongation profile viewed by two observers. These techniques are founded on themore » assumption that the transient can be characterized as a point source (fixed φ, FP, approximation) or a circle attached to Sun-center (harmonic mean, HM, approximation), respectively. These geometries constitute extreme descriptions of solar wind transients, in terms of their cross-sectional extent. Here, we present the stereoscopic expressions necessary to derive propagation direction and radial distance/speed profiles of such transients based on the more generalized self-similar expansion (SSE) geometry, for which the FP and HM geometries form the limiting cases; our implementation of these equations is termed the stereoscopic SSE method. We apply the technique to two Earth-directed CMEs from different phases of the STEREO mission, the well-studied event of 2008 December and a more recent event from 2012 March. The latter CME was fast, with an initial speed exceeding 2000 km s{sup –1}, and highly geoeffective, in stark contrast to the slow and ineffectual 2008 December CME.« less

Augmented reality to the rescue of the minimally invasive surgeon. The usefulness of the interposition of stereoscopic images in the Da Vinci™ robotic console.

PubMed

Volonté, Francesco; Buchs, Nicolas C; Pugin, François; Spaltenstein, Joël; Schiltz, Boris; Jung, Minoa; Hagen, Monika; Ratib, Osman; Morel, Philippe

2013-09-01

Computerized management of medical information and 3D imaging has become the norm in everyday medical practice. Surgeons exploit these emerging technologies and bring information previously confined to the radiology rooms into the operating theatre. The paper reports the authors' experience with integrated stereoscopic 3D-rendered images in the da Vinci surgeon console. Volume-rendered images were obtained from a standard computed tomography dataset using the OsiriX DICOM workstation. A custom OsiriX plugin was created that permitted the 3D-rendered images to be displayed in the da Vinci surgeon console and to appear stereoscopic. These rendered images were displayed in the robotic console using the TilePro multi-input display. The upper part of the screen shows the real endoscopic surgical field and the bottom shows the stereoscopic 3D-rendered images. These are controlled by a 3D joystick installed on the console, and are updated in real time. Five patients underwent a robotic augmented reality-enhanced procedure. The surgeon was able to switch between the classical endoscopic view and a combined virtual view during the procedure. Subjectively, the addition of the rendered images was considered to be an undeniable help during the dissection phase. With the rapid evolution of robotics, computer-aided surgery is receiving increasing interest. This paper details the authors' experience with 3D-rendered images projected inside the surgical console. The use of this intra-operative mixed reality technology is considered very useful by the surgeon. It has been shown that the usefulness of this technique is a step toward computer-aided surgery that will progress very quickly over the next few years. Copyright © 2012 John Wiley & Sons, Ltd.

Comparative Analysis of InSAR Digital Surface Models for Test Area Bucharest

NASA Astrophysics Data System (ADS)

Dana, Iulia; Poncos, Valentin; Teleaga, Delia

2010-03-01

This paper presents the results of the interferometric processing of ERS Tandem, ENVISAT and TerraSAR- X for digital surface model (DSM) generation. The selected test site is Bucharest (Romania), a built-up area characterized by the usual urban complex pattern: mixture of buildings with different height levels, paved roads, vegetation, and water bodies. First, the DSMs were generated following the standard interferometric processing chain. Then, the accuracy of the DSMs was analyzed against the SPOT HRS model (30 m resolution at the equator). A DSM derived by optical stereoscopic processing of SPOT 5 HRG data and also the SRTM (3 arc seconds resolution at the equator) DSM have been included in the comparative analysis.

Stereoscopic Planar Laser-Induced Fluorescence Imaging at 500 kHz

NASA Technical Reports Server (NTRS)

Medford, Taylor L.; Danehy, Paul M.; Jones, Stephen B.; Jiang, N.; Webster, M.; Lempert, Walter; Miller, J.; Meyer, T.

2011-01-01

A new measurement technique for obtaining time- and spatially-resolved image sequences in hypersonic flows is developed. Nitric-oxide planar laser-induced fluorescence (NO PLIF) has previously been used to investigate transition from laminar to turbulent flow in hypersonic boundary layers using both planar and volumetric imaging capabilities. Low flow rates of NO were typically seeded into the flow, minimally perturbing the flow. The volumetric imaging was performed at a measurement rate of 10 Hz using a thick planar laser sheet that excited NO fluorescence. The fluorescence was captured by a pair of cameras having slightly different views of the flow. Subsequent stereoscopic reconstruction of these images allowed the three-dimensional flow structures to be viewed. In the current paper, this approach has been extended to 50,000 times higher repetition rates. A laser operating at 500 kHz excites the seeded NO molecules, and a camera, synchronized with the laser and fitted with a beam-splitting assembly, acquires two separate images of the flow. The resulting stereoscopic images provide three-dimensional flow visualizations at 500 kHz for the first time. The 200 ns exposure time in each frame is fast enough to freeze the flow while the 500 kHz repetition rate is fast enough to time-resolve changes in the flow being studied. This method is applied to visualize the evolving hypersonic flow structures that propagate downstream of a discrete protuberance attached to a flat plate. The technique was demonstrated in the NASA Langley Research Center s 31-Inch Mach 10 Air Tunnel facility. Different tunnel Reynolds number conditions, NO flow rates and two different cylindrical protuberance heights were investigated. The location of the onset of flow unsteadiness, an indicator of transition, was observed to move downstream during the tunnel runs, coinciding with an increase in the model temperature.

Recovering Old Stereoscopic Negatives and Producing Digital 3d Models of Former Appearances of Historic Buildings

NASA Astrophysics Data System (ADS)

Rodríguez Miranda, Á.; Valle Melón, J. M.

2017-02-01

Three-dimensional models with photographic textures have become a usual product for the study and dissemination of elements of heritage. The interest for cultural heritage also includes evolution along time; therefore, apart from the 3D models of the current state, it is interesting to be able to generate models representing how they were in the past. To that end, it is necessary to resort to archive information corresponding to the moments that we want to visualize. This text analyses the possibilities of generating 3D models of surfaces with photographic textures from old collections of analog negatives coming from works of terrestrial stereoscopic photogrammetry of historic buildings. The case studies presented refer to the geometric documentation of a small hermitage (done in 1996) and two sections of a wall (year 2000). The procedure starts with the digitization of the film negatives and the processing of the images generated, after which a combination of different methods for 3D reconstruction and texture wrapping are applied: techniques working simultaneously with several images (such as the algorithms of Structure from Motion - SfM) and single image techniques (such as the reconstruction based on vanishing points). Then, the features of the obtained models are described according to the geometric accuracy, completeness and aesthetic quality. In this way, it is possible to establish the real applicability of the models in order to be useful for the aforementioned historical studies and dissemination purposes. The text also wants to draw attention to the importance of preserving the documentary heritage available in the collections of negatives in archival custody and to the increasing difficulty of using them due to: (1) problems of access and physical conservation, (2) obsolescence of the equipment for scanning and stereoplotting and (3) the fact that the software for processing digitized photographs is discontinued.

Stereoscopic Feature Tracking System for Retrieving Velocity of Surface Waters

NASA Astrophysics Data System (ADS)

Zuniga Zamalloa, C. C.; Landry, B. J.

2017-12-01

The present work is concerned with the surface velocity retrieval of flows using a stereoscopic setup and finding the correspondence in the images via feature tracking (FT). The feature tracking provides a key benefit of substantially reducing the level of user input. In contrast to other commonly used methods (e.g., normalized cross-correlation), FT does not require the user to prescribe interrogation window sizes and removes the need for masking when specularities are present. The results of the current FT methodology are comparable to those obtained via Large Scale Particle Image Velocimetry while requiring little to no user input which allowed for rapid, automated processing of imagery.

The mosaics of Mars: As seen by the Viking Lander cameras

NASA Technical Reports Server (NTRS)

Levinthal, E. C.; Jones, K. L.

1980-01-01

The mosaics and derivative products produced from many individual high resolution images acquired by the Viking Lander Camera Systems are described: A morning and afternoon mosaic for both cameras at the Lander 1 Chryse Planitia site, and a morning, noon, and afternoon camera pair at Utopia Planitia, the Lander 11 site. The derived products include special geometric projections of the mosaic data sets, polar stereographic (donut), stereoscopic, and orthographic. Contour maps and vertical profiles of the topography were overlaid on the mosaics from which they were derived. Sets of stereo pairs were extracted and enlarged from stereoscopic projections of the mosaics.

Toward virtual anatomy: a stereoscopic 3-D interactive multimedia computer program for cranial osteology.

PubMed

Trelease, R B

1996-01-01

Advances in computer visualization and user interface technologies have enabled development of "virtual reality" programs that allow users to perceive and to interact with objects in artificial three-dimensional environments. Such technologies were used to create an image database and program for studying the human skull, a specimen that has become increasingly expensive and scarce. Stereoscopic image pairs of a museum-quality skull were digitized from multiple views. For each view, the stereo pairs were interlaced into a single, field-sequential stereoscopic picture using an image processing program. The resulting interlaced image files are organized in an interactive multimedia program. At run-time, gray-scale 3-D images are displayed on a large-screen computer monitor and observed through liquid-crystal shutter goggles. Users can then control the program and change views with a mouse and cursor to point-and-click on screen-level control words ("buttons"). For each view of the skull, an ID control button can be used to overlay pointers and captions for important structures. Pointing and clicking on "hidden buttons" overlying certain structures triggers digitized audio spoken word descriptions or mini lectures.

Matching and correlation computations in stereoscopic depth perception.

PubMed

Doi, Takahiro; Tanabe, Seiji; Fujita, Ichiro

2011-03-02

A fundamental task of the visual system is to infer depth by using binocular disparity. To encode binocular disparity, the visual cortex performs two distinct computations: one detects matched patterns in paired images (matching computation); the other constructs the cross-correlation between the images (correlation computation). How the two computations are used in stereoscopic perception is unclear. We dissociated their contributions in near/far discrimination by varying the magnitude of the disparity across separate sessions. For small disparity (0.03°), subjects performed at chance level to a binocularly opposite-contrast (anti-correlated) random-dot stereogram (RDS) but improved their performance with the proportion of contrast-matched (correlated) dots. For large disparity (0.48°), the direction of perceived depth reversed with an anti-correlated RDS relative to that for a correlated one. Neither reversed nor normal depth was perceived when anti-correlation was applied to half of the dots. We explain the decision process as a weighted average of the two computations, with the relative weight of the correlation computation increasing with the disparity magnitude. We conclude that matching computation dominates fine depth perception, while both computations contribute to coarser depth perception. Thus, stereoscopic depth perception recruits different computations depending on the disparity magnitude.

Simulated disparity and peripheral blur interact during binocular fusion.

PubMed

Maiello, Guido; Chessa, Manuela; Solari, Fabio; Bex, Peter J

2014-07-17

We have developed a low-cost, practical gaze-contingent display in which natural images are presented to the observer with dioptric blur and stereoscopic disparity that are dependent on the three-dimensional structure of natural scenes. Our system simulates a distribution of retinal blur and depth similar to that experienced in real-world viewing conditions by emmetropic observers. We implemented the system using light-field photographs taken with a plenoptic camera which supports digital refocusing anywhere in the images. We coupled this capability with an eye-tracking system and stereoscopic rendering. With this display, we examine how the time course of binocular fusion depends on depth cues from blur and stereoscopic disparity in naturalistic images. Our results show that disparity and peripheral blur interact to modify eye-movement behavior and facilitate binocular fusion, and the greatest benefit was gained by observers who struggled most to achieve fusion. Even though plenoptic images do not replicate an individual’s aberrations, the results demonstrate that a naturalistic distribution of depth-dependent blur may improve 3-D virtual reality, and that interruptions of this pattern (e.g., with intraocular lenses) which flatten the distribution of retinal blur may adversely affect binocular fusion. © 2014 ARVO.

Simulated disparity and peripheral blur interact during binocular fusion

PubMed Central

Maiello, Guido; Chessa, Manuela; Solari, Fabio; Bex, Peter J

2014-01-01

We have developed a low-cost, practical gaze-contingent display in which natural images are presented to the observer with dioptric blur and stereoscopic disparity that are dependent on the three-dimensional structure of natural scenes. Our system simulates a distribution of retinal blur and depth similar to that experienced in real-world viewing conditions by emmetropic observers. We implemented the system using light-field photographs taken with a plenoptic camera which supports digital refocusing anywhere in the images. We coupled this capability with an eye-tracking system and stereoscopic rendering. With this display, we examine how the time course of binocular fusion depends on depth cues from blur and stereoscopic disparity in naturalistic images. Our results show that disparity and peripheral blur interact to modify eye-movement behavior and facilitate binocular fusion, and the greatest benefit was gained by observers who struggled most to achieve fusion. Even though plenoptic images do not replicate an individual's aberrations, the results demonstrate that a naturalistic distribution of depth-dependent blur may improve 3-D virtual reality, and that interruptions of this pattern (e.g., with intraocular lenses) which flatten the distribution of retinal blur may adversely affect binocular fusion. PMID:25034260

Stereoscopy in orthopaedics

NASA Astrophysics Data System (ADS)

Tan, S. L. E.

2005-03-01

Stereoscopy was used in medicine as long ago as 1898, but has not gained widespread acceptance except for a peak in the 1930's. It retains a use in orthopaedics in the form of Radiostereogrammetrical Analysis (RSA), though this is now done by computer software without using stereopsis. Combining computer assisted stereoscopic displays with both conventional plain films and reconstructed volumetric axial data, we are reassessing the use of stereoscopy in orthopaedics. Applications include use in developing nations or rural settings, erect patients where axial imaging cannot be used, and complex deformity and trauma reconstruction. Extension into orthopaedic endoscopic systems and teaching aids (e.g. operative videos) are further possibilities. The benefits of stereoscopic vision in increased perceived resolution and depth perception can help orthopaedic surgeons achieve more accurate diagnosis and better pre-operative planning. Limitations to currently available stereoscopic displays which need to be addressed prior to widespread acceptance are: availability of hardware and software, loss of resolution, use of glasses, and image "ghosting". Journal publication, the traditional mode of information dissemination in orthopaedics, is also viewed as a hindrance to the acceptance of stereoscopy - it does not deliver the full impact of stereoscopy and "hands-on" demonstrations are needed.

Stereoscopic Movies for Teaching and Learning of Astronomy

NASA Astrophysics Data System (ADS)

Hayashi, Mitsuru; Kato, Tsunehiko N.; Takeda, Takaaaki; Kokubo, Eiichiro; Miura, Hitoshi; Takahei, Toshiyuki; Miyama, Shoken M.; Kaifu, Norio

To attract the interest of the public in astronomy we visualize data obtained through simulations by using super computers and observations by using state-of -the-art facilities for example the SUBARU Telescope in the virtual reality system. The system is composed of three soft screens. We use two PC's two DLP projectors with circular polarization filters and one mirror for each screen to realize stereoscopic projection. By wearing glasses of circular polarization filters we can experience immersiveness in the system. Six PC's are connected by using optical fiber cable(1Gbps). Especially we developed the software for synchronization and realized stereoscopic movies(15-30 frames per second). In addition to teaching and learning of astronomy we also utilize the system above for public relations and science itself in NAO Mitaka. The system can provide scientists with the point of view we cannot realize on the earth. We are planning to improve the contents easier for the public to understand and distribute the contents to museums and educational institutions through networks for example Super SINET(the internet backbone connects institutes at 10Gbps) in 2003 in addition to monthly exhibition in NAOMitaka

Optoelectronic stereoscopic device for diagnostics, treatment, and developing of binocular vision

NASA Astrophysics Data System (ADS)

Pautova, Larisa; Elkhov, Victor A.; Ovechkis, Yuri N.

2003-08-01

Operation of the device is based on alternative generation of pictures for left and right eyes on the monitor screen. Controller gives pulses on LCG so that shutter for left or right eye opens synchronously with pictures. The device provides frequency of switching more than 100 Hz, and that is why the flickering is absent. Thus, a separate demonstration of images to the left eye or to the right one in turn is obtained for patients being unaware and creates the conditions of binocular perception clsoe to natural ones without any additional separation of vision fields. LC-cell transfer characteristic coodination with time parameters of monitor screen has enabled to improve stereo image quality. Complicated problem of computer stereo images with LC-glasses is so called 'ghosts' - noise images that come to blocked eye. We reduced its influence by adapting stereo images to phosphor and LC-cells characteristics. The device is intended for diagnostics and treatment of stabismus, amblyopia and other binocular and stereoscopic vision impairments, for cultivating, training and developing of stereoscopic vision, for measurements of horizontal and vertical phoria, phusion reserves, the stereovision acuity and some else, for fixing central scotoma borders, as well as suppression scotoma in strabismus too.

Viewing 3D TV over two months produces no discernible effects on balance, coordination or eyesight

PubMed Central

Read, Jenny C.A.; Godfrey, Alan; Bohr, Iwo; Simonotto, Jennifer; Galna, Brook; Smulders, Tom V.

2016-01-01

Abstract With the rise in stereoscopic 3D media, there has been concern that viewing stereoscopic 3D (S3D) content could have long-term adverse effects, but little data are available. In the first study to address this, 28 households who did not currently own a 3D TV were given a new TV set, either S3D or 2D. The 116 members of these households all underwent tests of balance, coordination and eyesight, both before they received their new TV set, and after they had owned it for 2 months. We did not detect any changes which appeared to be associated with viewing 3D TV. We conclude that viewing 3D TV does not produce detectable effects on balance, coordination or eyesight over the timescale studied. Practitioner Summary: Concern has been expressed over possible long-term effects of stereoscopic 3D (S3D). We looked for any changes in vision, balance and coordination associated with normal home S3D TV viewing in the 2 months after first acquiring a 3D TV. We find no evidence of any changes over this timescale. PMID:26758965

Depth reversals in stereoscopic displays driven by apparent size

NASA Astrophysics Data System (ADS)

Sacher, Gunnar; Hayes, Amy; Thornton, Ian M.; Sereno, Margaret E.; Malony, Allen D.

1998-04-01

In visual scenes, depth information is derived from a variety of monocular and binocular cues. When in conflict, a monocular cue is sometimes able to override the binocular information. We examined the accuracy of relative depth judgments in orthographic, stereoscopic displays and found that perceived relative size can override binocular disparity as a depth cue in a situation where the relative size information is itself generated from disparity information, not from retinal size difference. A size discrimination task confirmed the assumption that disparity information was perceived and used to generate apparent size differences. The tendency for the apparent size cue to override disparity information can be modulated by varying the strength of the apparent size cue. In addition, an analysis of reaction times provides supporting evidence for this novel depth reversal effect. We believe that human perception must be regarded as an important component of stereoscopic applications. Hence, if applications are to be effective and accurate, it is necessary to take into account the richness and complexity of the human visual perceptual system that interacts with them. We discuss implications of this and similar research for human performance in virtual environments, the design of visual presentations for virtual worlds, and the design of visualization tools.

Evaluation of stereoscopic display with visual function and interview

NASA Astrophysics Data System (ADS)

Okuyama, Fumio

1999-05-01

The influence of binocular stereoscopic (3D) television display on the human eye were compared with one of a 2D display, using human visual function testing and interviews. A 40- inch double lenticular display was used for 2D/3D comparison experiments. Subjects observed the display for 30 minutes at a distance 1.0 m, with a combination of 2D material and one of 3D material. The participants were twelve young adults. Main optometric test with visual function measured were visual acuity, refraction, phoria, near vision point, accommodation etc. The interview consisted of 17 questions. Testing procedures were performed just before watching, just after watching, and forty-five minutes after watching. Changes in visual function are characterized as prolongation of near vision point, decrease of accommodation and increase in phoria. 3D viewing interview results show much more visual fatigue in comparison with 2D results. The conclusions are: 1) change in visual function is larger and visual fatigue is more intense when viewing 3D images. 2) The evaluation method with visual function and interview proved to be very satisfactory for analyzing the influence of stereoscopic display on human eye.

Photogrammetry using Apollo 16 orbital photography, part B

NASA Technical Reports Server (NTRS)

Wu, S. S. C.; Schafer, F. J.; Jordan, R.; Nakata, G. M.

1972-01-01

Discussion is made of the Apollo 15 and 16 metric and panoramic cameras which provided photographs for accurate topographic portrayal of the lunar surface using photogrammetric methods. Nine stereoscopic models of Apollo 16 metric photographs and three models of panoramic photographs were evaluated photogrammetrically in support of the Apollo 16 geologic investigations. Four of the models were used to collect profile data for crater morphology studies; three models were used to collect evaluation data for the frequency distributions of lunar slopes; one model was used to prepare a map of the Apollo 16 traverse area; and one model was used to determine elevations of the Cayley Formation. The remaining three models were used to test photogrammetric techniques using oblique metric and panoramic camera photographs. Two preliminary contour maps were compiled and a high-oblique metric photograph was rectified.

Volcanic Plume Elevation Model Derived From Landsat 8: examples on Holuhraun (Iceland) and Mount Etna (Italy)

NASA Astrophysics Data System (ADS)

de Michele, Marcello; Raucoules, Daniel; Arason, Þórður; Spinetti, Claudia; Corradini, Stefano; Merucci, Luca

2016-04-01

The retrieval of both height and velocity of a volcanic plume is an important issue in volcanology. As an example, it is known that large volcanic eruptions can temporarily alter the climate, causing global cooling and shifting precipitation patterns; the ash/gas dispersion in the atmosphere, their impact and lifetime around the globe, greatly depends on the injection altitude. Plume height information is critical for ash dispersion modelling and air traffic security. Furthermore, plume height during explosive volcanism is the primary parameter for estimating mass eruption rate. Knowing the plume altitude is also important to get the correct amount of SO2 concentration from dedicated spaceborne spectrometers. Moreover, the distribution of ash deposits on ground greatly depends on the ash cloud altitude, which has an impact on risk assessment and crisis management. Furthermore, a spatially detailed plume height measure could be used as a hint for gas emission rate estimation and for ash plume volume researches, which both have an impact on climate research, air quality assessment for aviation and finally for the understanding of the volcanic system itself as ash/gas emission rates are related to the state of pressurization of the magmatic chamber. Today, the community mainly relies on ground based measurements but often they can be difficult to collect as by definition volcanic areas are dangerous areas (presence of toxic gases) and can be remotely situated and difficult to access. Satellite remote sensing offers a comprehensive and safe way to estimate plume height. Conventional photogrammetric restitution based on satellite imagery fails in precisely retrieving a plume elevation model as the plume own velocity induces an apparent parallax that adds up to the standard parallax given by the stereoscopic view. Therefore, measurements based on standard satellite photogrammeric restitution do not apply as there is an ambiguity in the measurement of the plume position. Standard spaceborne along-track stereo imagers (e.g. SPOT 5, ASTER or Quickbird among the others) present a long temporal lag between the two stereo image acquisitions. It can reach tens of seconds for baseline-to-height ratios (B/H) between 0.2 and 0.5, during which time the surface texture of the plume may have changed due to the plume fast displacement (i.e. velocities larger than 10 m/s) biasing automatic cross correlation offset measurements. For the purpose of the plume surface elevation model extraction, the ideal is as small as possible time lag, with still a B/H ratio large enough to provide a stereoscopic view for restituting the height. In this study we present a method to restitute a detailed map of the surface height of a volcanic eruptive column from optical satellite imagery. We call it the volcanic Plume Elevation Model (PEM). As the volcanic plume is moving rapidly, conventional satellite based photogrammetric height restitution methods do not apply as the epipolar offset due to plume motion adds up to the one generated by the stereoscopic view. This is because there are time-lags of tens of seconds between conventional satellite stereoscopic acquisitions, depending on the stereo acquisition mode. Our method is based on a single satellite pass. We exploit the short time lag and resulting baseline that exist between the multispectral (MS) and the panchromatic (PAN) bands to jointly measure the epipolar offsets and the perpendicular to the epipolar (P2E) offsets. The former are proportional to plume height plus the offsets due to plume velocity in the epipolar direction. The latter, are proportional to plume velocity in the P2E direction only. The latter is used to compensate the effect of plume velocity in the stereoscopic offsets by projecting it on the epipolar direction assuming a known plume direction, thus improving the height measurement precision. We apply the method to Landsat 8 data taking into account the specificities of the focal plane modules. We focus on the Holuhraun 2014 fissure eruption (Iceland) and on Mount Etna (Italy) 2013 episode. We validate our measurements against ground based measurements. The method has potential for detailed high resolution routine measurements of volcanic plume height/velocity. The method can be applied both to other multi focal plane modules push broom sensors (such as the ESA Sentinel 2) and potentially to other push-broom systems such as the CNES SPOT family and Pléiades.

Interactions between chromatic- and luminance-contrast-sensitive stereopsis mechanisms.

PubMed

Simmons, David R; Kingdom, Frederick A A

2002-06-01

It is well known that chromatic information can assist in solving the stereo correspondence problem. It has also been suggested that there are two independent first-order stereopsis mechanisms, one sensitive to chromatic contrast and the other sensitive to luminance contrast (Vision Research 37 (1997) 1271). Could the effect of chromatic information on stereo correspondence be subserved by interactions between these mechanisms? To address this question, disparity thresholds (1/stereoacuity) were measured using 0.5 cpd Gabor patches. The stimuli possessed different relative amounts of chromatic and luminance contrast which could be correlated or anti-correlated between the eyes. Stereoscopic performance with these compound stimuli was compared to that with purely isoluminant and isochromatic stimuli at different contrasts. It was found that anti-correlated chromatic contrast severely disrupted stereopsis with achromatic stimuli and that anti-correlated luminance contrast severely disrupted stereopsis with chromatic stimuli. Less dramatic, but still significant, was the improvement in stereoacuity obtained using correlated colour and luminance contrast. These data are consistent with there being positive and negative interactions between chromatic and achromatic stereopsis mechanisms that take place after the initial encoding of disparity information, but before the extraction of stereoscopic depth. These interactions can be modelled satisfactorily assuming probability summation of depth sign information between independent mechanisms.

Preoperative evaluation of neurovascular relationships for microvascular decompression in the cerebellopontine angle in a virtual reality environment.

PubMed

Du, Zhuo-Ying; Gao, Xiang; Zhang, Xiao-Luo; Wang, Zhi-Qiu; Tang, Wei-Jun

2010-09-01

In this paper the authors' goal was to evaluate the feasibility and efficacy of a virtual reality (VR) system in preoperative planning for microvascular decompression (MVD) procedures treating idiopathic trigeminal neuralgia and hemifacial spasm. The system's role in surgical simulation and training was also assessed. Between May 2008 and April 2009, the authors used the Dextroscope system to visualize the neurovascular complex and simulate MVD in the cerebellopontine angle in a VR environment in 16 patients (6 patients had trigeminal neuralgia and 10 had hemifacial spasm). Reconstructions were carried out 2-3 days before MVD. Images were printed in a red-blue stereoscopic format for teaching and discussion and were brought into the operating room to be compared with real-time intraoperative findings. The VR environment was a powerful aid for spatial understanding of the neurovascular relationship in MVD for operating surgeons and trainees. Through an initial series of comparison/confirmation experiences, the senior neurosurgeon became accustomed to the system. He could predict intraoperative problems and simulate surgical maneuvering, which increased his confidence in performing the procedure. The Dextroscope system is an easy and rapid method to create a stereoscopic neurovascular model for MVD that is highly concordant with intraoperative findings. It effectively shortens the learning curve and adds to the surgeon's confidence.

A three-dimensional study of the glottal jet

NASA Astrophysics Data System (ADS)

Krebs, F.; Silva, F.; Sciamarella, D.; Artana, G.

2012-05-01

This work builds upon the efforts to characterize the three-dimensional features of the glottal jet during vocal fold vibration. The study uses a Stereoscopic Particle Image Velocimetry setup on a self-oscillating physical model of the vocal folds with a uniform vocal tract. Time averages are documented and analyzed within the framework given by observations reported for jets exiting elongated nozzles. Phase averages are locked to the audio signal and used to obtain a volumetric reconstruction of the jet. From this reconstruction, the intra-cycle dynamics of the jet axis switching is disclosed.

SPHERES Vertigo

NASA Image and Video Library

2014-07-25

ISS040-E-079355 (25 July 2014) --- In the International Space Station?s Kibo laboratory, NASA astronaut Steve Swanson (foreground), Expedition 40 commander; and European Space Agency astronaut Alexander Gerst, flight engineer, conduct a session with a trio of soccer-ball-sized robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The free-flying robots were equipped with stereoscopic goggles called the Visual Estimation and Relative Tracking for Inspection of Generic Objects, or VERTIGO, to enable the SPHERES to perform relative navigation based on a 3D model of a target object.

SPHERES Vertigo

NASA Image and Video Library

2014-07-25

ISS040-E-079129 (25 July 2014) --- In the International Space Station?s Kibo laboratory, NASA astronaut Steve Swanson (left), Expedition 40 commander; and European Space Agency astronaut Alexander Gerst, flight engineer, conduct a session with a trio of soccer-ball-sized robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The free-flying robots were equipped with stereoscopic goggles called the Visual Estimation and Relative Tracking for Inspection of Generic Objects, or VERTIGO, to enable the SPHERES to perform relative navigation based on a 3D model of a target object.

SPHERES Vertigo

NASA Image and Video Library

2014-07-25

ISS040-E-079910 (25 July 2014) --- In the International Space Station?s Kibo laboratory, NASA astronaut Steve Swanson (left), Expedition 40 commander; and European Space Agency astronaut Alexander Gerst, flight engineer, conduct a session with a trio of soccer-ball-sized robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The free-flying robots were equipped with stereoscopic goggles called the Visual Estimation and Relative Tracking for Inspection of Generic Objects, or VERTIGO, to enable the SPHERES to perform relative navigation based on a 3D model of a target object.

SPHERES Vertigo

NASA Image and Video Library

2014-07-25

ISS040-E-079332 (25 July 2014) --- In the International Space Station?s Kibo laboratory, NASA astronaut Steve Swanson (foreground), Expedition 40 commander; and European Space Agency astronaut Alexander Gerst, flight engineer, conduct a session with a trio of soccer-ball-sized robots known as the Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. The free-flying robots were equipped with stereoscopic goggles called the Visual Estimation and Relative Tracking for Inspection of Generic Objects, or VERTIGO, to enable the SPHERES to perform relative navigation based on a 3D model of a target object.

Streaming video-based 3D reconstruction method compatible with existing monoscopic and stereoscopic endoscopy systems

NASA Astrophysics Data System (ADS)

Bouma, Henri; van der Mark, Wannes; Eendebak, Pieter T.; Landsmeer, Sander H.; van Eekeren, Adam W. M.; ter Haar, Frank B.; Wieringa, F. Pieter; van Basten, Jean-Paul

2012-06-01

Compared to open surgery, minimal invasive surgery offers reduced trauma and faster recovery. However, lack of direct view limits space perception. Stereo-endoscopy improves depth perception, but is still restricted to the direct endoscopic field-of-view. We describe a novel technology that reconstructs 3D-panoramas from endoscopic video streams providing a much wider cumulative overview. The method is compatible with any endoscope. We demonstrate that it is possible to generate photorealistic 3D-environments from mono- and stereoscopic endoscopy. The resulting 3D-reconstructions can be directly applied in simulators and e-learning. Extended to real-time processing, the method looks promising for telesurgery or other remote vision-guided tasks.

Stereoscopic, Force-Feedback Trainer For Telerobot Operators

NASA Technical Reports Server (NTRS)

Kim, Won S.; Schenker, Paul S.; Bejczy, Antal K.

1994-01-01

Computer-controlled simulator for training technicians to operate remote robots provides both visual and kinesthetic virtual reality. Used during initial stage of training; saves time and expense, increases operational safety, and prevents damage to robots by inexperienced operators. Computes virtual contact forces and torques of compliant robot in real time, providing operator with feel of forces experienced by manipulator as well as view in any of three modes: single view, two split views, or stereoscopic view. From keyboard, user specifies force-reflection gain and stiffness of manipulator hand for three translational and three rotational axes. System offers two simulated telerobotic tasks: insertion of peg in hole in three dimensions, and removal and insertion of drawer.

Vision in our three-dimensional world

PubMed Central

2016-01-01

Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269595

Stereoscopic Particle Image Velocimetry Used to Study the Wake Patterns of an Ideal Anguilliform Swimming Motion

NASA Astrophysics Data System (ADS)

Taravella, Brandon; Potts, J. Baker; Stegmeir, Matthew

2014-11-01

The University of New Orleans recently acquired a self-contained stereoscopic particle image velocimetry system for use in their 125 ft long towing tank. This system is being used to study the wake flow behind an anguilliform swimming robot that swims with an ideal motion that is theorized not to produce any trailing vortices. The presentation will describe the particulars of the SPIV system along with details of installation of the SPIV system within the towing tank. The calibration routine will be discussed in detail and results of the free-flow runs will be discussed. Preliminary results from the anguilliform swimming motion will also be presented.

A tool for the estimation of the distribution of landslide area in R

NASA Astrophysics Data System (ADS)

Rossi, M.; Cardinali, M.; Fiorucci, F.; Marchesini, I.; Mondini, A. C.; Santangelo, M.; Ghosh, S.; Riguer, D. E. L.; Lahousse, T.; Chang, K. T.; Guzzetti, F.

2012-04-01

We have developed a tool in R (the free software environment for statistical computing, http://www.r-project.org/) to estimate the probability density and the frequency density of landslide area. The tool implements parametric and non-parametric approaches to the estimation of the probability density and the frequency density of landslide area, including: (i) Histogram Density Estimation (HDE), (ii) Kernel Density Estimation (KDE), and (iii) Maximum Likelihood Estimation (MLE). The tool is available as a standard Open Geospatial Consortium (OGC) Web Processing Service (WPS), and is accessible through the web using different GIS software clients. We tested the tool to compare Double Pareto and Inverse Gamma models for the probability density of landslide area in different geological, morphological and climatological settings, and to compare landslides shown in inventory maps prepared using different mapping techniques, including (i) field mapping, (ii) visual interpretation of monoscopic and stereoscopic aerial photographs, (iii) visual interpretation of monoscopic and stereoscopic VHR satellite images and (iv) semi-automatic detection and mapping from VHR satellite images. Results show that both models are applicable in different geomorphological settings. In most cases the two models provided very similar results. Non-parametric estimation methods (i.e., HDE and KDE) provided reasonable results for all the tested landslide datasets. For some of the datasets, MLE failed to provide a result, for convergence problems. The two tested models (Double Pareto and Inverse Gamma) resulted in very similar results for large and very large datasets (> 150 samples). Differences in the modeling results were observed for small datasets affected by systematic biases. A distinct rollover was observed in all analyzed landslide datasets, except for a few datasets obtained from landslide inventories prepared through field mapping or by semi-automatic mapping from VHR satellite imagery. The tool can also be used to evaluate the probability density and the frequency density of landslide volume.

Surface topography characterization using 3D stereoscopic reconstruction of SEM images

NASA Astrophysics Data System (ADS)

Vedantha Krishna, Amogh; Flys, Olena; Reddy, Vijeth V.; Rosén, B. G.

2018-06-01

A major drawback of the optical microscope is its limitation to resolve finer details. Many microscopes have been developed to overcome the limitations set by the diffraction of visible light. The scanning electron microscope (SEM) is one such alternative: it uses electrons for imaging, which have much smaller wavelength than photons. As a result high magnification with superior image resolution can be achieved. However, SEM generates 2D images which provide limited data for surface measurements and analysis. Often many research areas require the knowledge of 3D structures as they contribute to a comprehensive understanding of microstructure by allowing effective measurements and qualitative visualization of the samples under study. For this reason, stereo photogrammetry technique is employed to convert SEM images into 3D measurable data. This paper aims to utilize a stereoscopic reconstruction technique as a reliable method for characterization of surface topography. Reconstructed results from SEM images are compared with coherence scanning interferometer (CSI) results obtained by measuring a roughness reference standard sample. This paper presents a method to select the most robust/consistent surface texture parameters that are insensitive to the uncertainties involved in the reconstruction technique itself. Results from the two-stereoscopic reconstruction algorithms are also documented in this paper.

A GeoWall with Physics and Astronomy Applications

NASA Astrophysics Data System (ADS)

Dukes, Phillip; Bruton, Dan

2008-03-01

A GeoWall is a passive stereoscopic projection system that can be used by students, teachers, and researchers for visualization of the structure and dynamics of three-dimensional systems and data. The type of system described here adequately provides 3-D visualization in natural color for large or small groups of viewers. The name ``GeoWall'' derives from its initial development to visualize data in the geosciences.1 An early GeoWall system was developed by Paul Morin at the electronic visualization laboratory at the University of Minnesota and was applied in an introductory geology course in spring of 2001. Since that time, several stereoscopic media, which are applicable to introductory-level physics and astronomy classes, have been developed and released into the public domain. In addition to the GeoWall's application in the classroom, there is considerable value in its use as part of a general science outreach program. In this paper we briefly describe the theory of operation of stereoscopic projection and the basic necessary components of a GeoWall system. Then we briefly describe how we are using a GeoWall as an instructional tool for the classroom and informal astronomy education and in research. Finally, we list sources for several of the free software media in physics and astronomy available for use with a GeoWall system.

Broadcast-quality-stereoscopic video in a time-critical entertainment and corporate environment

NASA Astrophysics Data System (ADS)

Gay, Jean-Philippe

1995-03-01

`reality present: Peter Gabrial and Cirque du Soleil' is a 12 minute original work directed and produced by Doug Brown, Jean-Philippe Gay & A. Coogan, which showcases creative content applications of commercial stereoscopic video equipment. For production, a complete equipment package including a Steadicam mount was used in support of the Ikegami LK-33 camera. Remote production units were fielded in the time critical, on-stage and off-stage environments of 2 major live concerts: Peter Gabriel's Secret World performance at the San Diego Sports Arena, and Cirque du Soleil's Saltimbanco performance in Chicago. Twin 60 Hz video channels were captured on Beta SP for maximum post production flexibility. Digital post production and field sequential mastering were effected in D-2 format at studio facilities in Los Angeles. The program was world premiered to a large public at the World of Music, Arts and Dance festivals in Los Angeles and San Francisco, in late 1993. It was presented to the artists in Los Angeles, Montreal and Washington D.C. Additional presentations have been made using a broad range of commercial and experimental stereoscopic video equipment, including projection systems, LCD and passive eyewear, and digital signal processors. Technical packages for live presentation have been fielded on site and off, through to the present.

Virtual and stereoscopic anatomy: when virtual reality meets medical education.

PubMed

de Faria, Jose Weber Vieira; Teixeira, Manoel Jacobsen; de Moura Sousa Júnior, Leonardo; Otoch, Jose Pinhata; Figueiredo, Eberval Gadelha

2016-11-01

OBJECTIVE The authors sought to construct, implement, and evaluate an interactive and stereoscopic resource for teaching neuroanatomy, accessible from personal computers. METHODS Forty fresh brains (80 hemispheres) were dissected. Images of areas of interest were captured using a manual turntable and processed and stored in a 5337-image database. Pedagogic evaluation was performed in 84 graduate medical students, divided into 3 groups: 1 (conventional method), 2 (interactive nonstereoscopic), and 3 (interactive and stereoscopic). The method was evaluated through a written theory test and a lab practicum. RESULTS Groups 2 and 3 showed the highest mean scores in pedagogic evaluations and differed significantly from Group 1 (p < 0.05). Group 2 did not differ statistically from Group 3 (p > 0.05). Size effects, measured as differences in scores before and after lectures, indicate the effectiveness of the method. ANOVA results showed significant difference (p < 0.05) between groups, and the Tukey test showed statistical differences between Group 1 and the other 2 groups (p < 0.05). No statistical differences between Groups 2 and 3 were found in the practicum. However, there were significant differences when Groups 2 and 3 were compared with Group 1 (p < 0.05). CONCLUSIONS The authors conclude that this method promoted further improvement in knowledge for students and fostered significantly higher learning when compared with traditional teaching resources.

Discussion on Height Systems in Stereoscopic Mapping Using the ZY-3 Satellite Images

NASA Astrophysics Data System (ADS)

Zhao, L.; Fu, X.; Zhu, G.; Zhang, J.; Han, C.; Cheng, L.

2018-04-01

The ZY-3 is the civil high-resolution optical stereoscopic mapping satellite independently developed by China. It is mainly used for 1 : 50,000 scale topographic mapping. One of the distinguishing features of the ZY-3 is that the panchromatic triplet camera can obtain thousands of kilometers of continuous strip stereo data. The working mode is suitable for wide-range stereoscopic mapping, in particular global DEM extraction. The ZY-3 constellation is operated in a sun-synchronous at an altitude 505 km, with a 10:30 AM equator crossing time and a 29-day revisiting period. The panchromatic triplet sensors have excellent base-to-height ratio, which is advantageous for obtaining good mapping accuracy. In this paper the China quasi-geoid, EGM2008 and the height conversion method are discussed. It is pointed out that according to the current surveying and mapping specifications, almost all maps and charts use mean sea level for elevation. Experiments on bundle adjustment and DEM extraction with different height systems have been carried out in Liaoning Province of China. The results show that the similar accuracy can be obtained using different elevation system. According to the principle of geodesy and photogrammetry, it is recommended to use ellipsoidal height for satellite photogrammetric calculation and use the orthometric height in mapping production.

Combining volumetric edge display and multiview display for expression of natural 3D images

NASA Astrophysics Data System (ADS)

Yasui, Ryota; Matsuda, Isamu; Kakeya, Hideki

2006-02-01

In the present paper the authors present a novel stereoscopic display method combining volumetric edge display technology and multiview display technology to realize presentation of natural 3D images where the viewers do not suffer from contradiction between binocular convergence and focal accommodation of the eyes, which causes eyestrain and sickness. We adopt volumetric display method only for edge drawing, while we adopt stereoscopic approach for flat areas of the image. Since focal accommodation of our eyes is affected only by the edge part of the image, natural focal accommodation can be induced if the edges of the 3D image are drawn on the proper depth. The conventional stereo-matching technique can give us robust depth values of the pixels which constitute noticeable edges. Also occlusion and gloss of the objects can be roughly expressed with the proposed method since we use stereoscopic approach for the flat area. We can attain a system where many users can view natural 3D objects at the consistent position and posture at the same time in this system. A simple optometric experiment using a refractometer suggests that the proposed method can give us 3-D images without contradiction between binocular convergence and focal accommodation.

Optometric measurements predict performance but not comfort on a virtual object placement task with a stereoscopic three-dimensional display

NASA Astrophysics Data System (ADS)

McIntire, John P.; Wright, Steve T.; Harrington, Lawrence K.; Havig, Paul R.; Watamaniuk, Scott N. J.; Heft, Eric L.

2014-06-01

Twelve participants were tested on a simple virtual object precision placement task while viewing a stereoscopic three-dimensional (S3-D) display. Inclusion criteria included uncorrected or best corrected vision of 20/20 or better in each eye and stereopsis of at least 40 arc sec using the Titmus stereotest. Additionally, binocular function was assessed, including measurements of distant and near phoria (horizontal and vertical) and distant and near horizontal fusion ranges using standard optometric clinical techniques. Before each of six 30 min experimental sessions, measurements of phoria and fusion ranges were repeated using a Keystone View Telebinocular and an S3-D display, respectively. All participants completed experimental sessions in which the task required the precision placement of a virtual object in depth at the same location as a target object. Subjective discomfort was assessed using the simulator sickness questionnaire. Individual placement accuracy in S3-D trials was significantly correlated with several of the binocular screening outcomes: viewers with larger convergent fusion ranges (measured at near distance), larger total fusion ranges (convergent plus divergent ranges, measured at near distance), and/or lower (better) stereoscopic acuity thresholds were more accurate on the placement task. No screening measures were predictive of subjective discomfort, perhaps due to the low levels of discomfort induced.

Measuring X-ray anisotropy in solar flares. Prospective stereoscopic capabilities of STIX and MiSolFA

NASA Astrophysics Data System (ADS)

Casadei, Diego; Jeffrey, Natasha L. S.; Kontar, Eduard P.

2017-09-01

Context. During a solar flare, a large percentage of the magnetic energy released goes into the kinetic energy of non-thermal particles, with X-ray observations providing a direct connection to keV flare-accelerated electrons. However, the electron angular distribution, a prime diagnostic tool of the acceleration mechanism and transport, is poorly known. Aims: During the next solar maximum, two upcoming space-borne X-ray missions, STIX on board Solar Orbiter and MiSolFA, will perform stereoscopic X-ray observations of solar flares at two different locations: STIX at 0.28 AU (at perihelion) and up to inclinations of 25°, and MiSolFA in a low-Earth orbit. The combined observations from these cross-calibrated detectors will allow us to infer the electron anisotropy of individual flares confidently for the first time. Methods: We simulated both instrumental and physical effects for STIX and MiSolFA including thermal shielding, background and X-ray Compton backscattering (albedo effect) in the solar photosphere. We predict the expected number of observable flares available for stereoscopic measurements during the next solar maximum. We also discuss the range of useful spacecraft observation angles for the challenging case of close-to-isotropic flare anisotropy. Results: The simulated results show that STIX and MiSolFA will be capable of detecting low levels of flare anisotropy, for M1-class or stronger flares, even with a relatively small spacecraft angular separation of 20-30°. Both instruments will directly measure the flare X-ray anisotropy of about 40 M- and X-class solar flares during the next solar maximum. Conclusions: Near-future stereoscopic observations with Solar Orbiter/STIX and MiSolFA will help distinguishing between competing flare-acceleration mechanisms, and provide essential constraints regarding collisional and non-collisional transport processes occurring in the flaring atmosphere for individual solar flares.

Fast camera observations of injected and intrinsic dust in TEXTOR

NASA Astrophysics Data System (ADS)

Shalpegin, A.; Vignitchouk, L.; Erofeev, I.; Brochard, F.; Litnovsky, A.; Bozhenkov, S.; Bykov, I.; den Harder, N.; Sergienko, G.

2015-12-01

Stereoscopic fast camera observations of pre-characterized carbon and tungsten dust injection in TEXTOR are reported, along with the modelling of tungsten particle trajectories with MIGRAINe. Particle tracking analysis of the video data showed significant differences in dust dynamics: while carbon flakes were prone to agglomeration and explosive destruction, spherical tungsten particles followed quasi-inertial trajectories. Although this inertial nature prevented any validation of the force models used in MIGRAINe, comparisons between the experimental and simulated lifetimes provide a direct evidence of dust temperature overestimation in dust dynamics codes. Furthermore, wide-view observations of the TEXTOR interior revealed the main production mechanism of intrinsic carbon dust, as well as the location of probable dust remobilization sites.

A comparative study of manhole hydraulics using stereoscopic PIV and different RANS models.

PubMed

Beg, Md Nazmul Azim; Carvalho, Rita F; Tait, Simon; Brevis, Wernher; Rubinato, Matteo; Schellart, Alma; Leandro, Jorge

2017-04-01

Flows in manholes are complex and may include swirling and recirculation flow with significant turbulence and vorticity. However, how these complex 3D flow patterns could generate different energy losses and so affect flow quantity in the wider sewer network is unknown. In this work, 2D3C stereo Particle Image Velocimetry measurements are made in a surcharged scaled circular manhole. A computational fluid dynamics (CFD) model in OpenFOAM ® with four different Reynolds Averaged Navier Stokes (RANS) turbulence model is constructed using a volume of fluid model, to represent flows in this manhole. Velocity profiles and pressure distributions from the models are compared with the experimental data in view of finding the best modelling approach. It was found among four different RANS models that the re-normalization group (RNG) k-ɛ and k-ω shear stress transport (SST) gave a better approximation for velocity and pressure.

Neural Integration of Information Specifying Human Structure from Form, Motion, and Depth

PubMed Central

Jackson, Stuart; Blake, Randolph

2010-01-01

Recent computational models of biological motion perception operate on ambiguous two-dimensional representations of the body (e.g., snapshots, posture templates) and contain no explicit means for disambiguating the three-dimensional orientation of a perceived human figure. Are there neural mechanisms in the visual system that represent a moving human figure’s orientation in three dimensions? To isolate and characterize the neural mechanisms mediating perception of biological motion, we used an adaptation paradigm together with bistable point-light (PL) animations whose perceived direction of heading fluctuates over time. After exposure to a PL walker with a particular stereoscopically defined heading direction, observers experienced a consistent aftereffect: a bistable PL walker, which could be perceived in the adapted orientation or reversed in depth, was perceived predominantly reversed in depth. A phase-scrambled adaptor produced no aftereffect, yet when adapting and test walkers differed in size or appeared on opposite sides of fixation aftereffects did occur. Thus, this heading direction aftereffect cannot be explained by local, disparity-specific motion adaptation, and the properties of scale and position invariance imply higher-level origins of neural adaptation. Nor is disparity essential for producing adaptation: when suspended on top of a stereoscopically defined, rotating globe, a context-disambiguated “globetrotter” was sufficient to bias the bistable walker’s direction, as were full-body adaptors. In sum, these results imply that the neural signals supporting biomotion perception integrate information on the form, motion, and three-dimensional depth orientation of the moving human figure. Models of biomotion perception should incorporate mechanisms to disambiguate depth ambiguities in two-dimensional body representations. PMID:20089892

Film patterned retarder for stereoscopic three-dimensional display using ink-jet printing method.

PubMed

Lim, Young Jin; Yu, Ji Hoon; Song, Ki Hoon; Lee, Myong-Hoon; Ren, Hongwen; Mun, Byung-June; Lee, Gi-Dong; Lee, Seung Hee

2014-09-22

We propose a film patterned retarder (FPR) for stereoscopic three-dimensional display with polarization glasses using ink-jet printing method. Conventional FPR process requires coating of photo-alignment and then UV exposure using wire-grid mask, which is very expensive and difficult. The proposed novel fabrication method utilizes a plastic substrate made of polyether sulfone and an alignment layer, poly (4, 4' - (9, 9 -fluorenyl) diphenylene cyclobutanyltetracarboximide) (9FDA/CBDA) in which the former and the latter aligns reactive mesogen along and perpendicular to the rubbing direction, respectively. The ink-jet printing of 9FDA/CBDA line by line allows fabricating the cost effective FPR which can be widely applied for 3D display applications.

Stereoscopic optical viewing system

DOEpatents

Tallman, C.S.

1986-05-02

An improved optical system which provides the operator with a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

Efficient simulation of intensity profile of light through subpixel-matched lenticular lens array for two- and four-view auto-stereoscopic liquid-crystal display.

PubMed

Chang, Yia-Chung; Tang, Li-Chuan; Yin, Chun-Yi

2013-01-01

Both an analytical formula and an efficient numerical method for simulation of the accumulated intensity profile of light that is refracted through a lenticular lens array placed on top of a liquid-crystal display (LCD) are presented. The influence due to light refracted through adjacent lens is examined in the two-view and four-view systems. Our simulation results are in good agreement with those obtained by a piece of commercial software, ASAP, but our method is much more efficient. This proposed method allows one to adjust the design parameters and carry out simulation for the performance of a subpixel-matched auto-stereoscopic LCD more efficiently and easily.

A Topological Array Trigger for AGIS, the Advanced Gamma ray Imaging System

NASA Astrophysics Data System (ADS)

Krennrich, F.; Anderson, J.; Buckley, J.; Byrum, K.; Dawson, J.; Drake, G.; Haberichter, W.; Imran, A.; Krawczynski, H.; Kreps, A.; Schroedter, M.; Smith, A.

2008-12-01

Next generation ground based γ-ray observatories such as AGIS1 and CTA2 are expected to cover a 1 km2 area with 50-100 imaging atmospheric Cherenkov telescopes. The stereoscopic view ol air showers using multiple view points raises the possibility to use a topological array trigger that adds substantial flexibility, new background suppression capabilities and a reduced energy threshold. In this paper we report on the concept and technical implementation of a fast topological trigger system, that makes use of real time image processing of individual camera patterns and their combination in a stereoscopic array analysis. A prototype system is currently under construction and we discuss the design and hardware of this topological array trigger system.

Stereoscopic optical viewing system

DOEpatents

Tallman, Clifford S.

1987-01-01

An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

Quantum vision in three dimensions

NASA Astrophysics Data System (ADS)

Roth, Yehuda

We present four models for describing a 3-D vision. Similar to the mirror scenario, our models allow 3-D vision with no need for additional accessories such as stereoscopic glasses or a hologram film. These four models are based on brain interpretation rather than pure objective encryption. We consider the observer "subjective" selection of a measuring device and the corresponding quantum collapse into one of his selected states, as a tool for interpreting reality in according to the observer concepts. This is the basic concept of our study and it is introduced in the first model. Other models suggests "soften" versions that might be much easier to implement. Our quantum interpretation approach contribute to the following fields. In technology the proposed models can be implemented into real devices, allowing 3-D vision without additional accessories. Artificial intelligence: In the desire to create a machine that exchange information by using human terminologies, our interpretation approach seems to be appropriate.

The dynamics of turbulent premixed flames: Mechanisms and models for turbulence-flame interaction

NASA Astrophysics Data System (ADS)

Steinberg, Adam M.

The use of turbulent premixed combustion in engines has been garnering renewed interest due to its potential to reduce NOx emissions. However there are many aspects of turbulence-flame interaction that must be better understood before such flames can be accurately modeled. The focus of this dissertation is to develop an improved understanding for the manner in which turbulence interacts with a premixed flame in the 'thin flamelet regime'. To do so, two new diagnostics were developed and employed in a turbulent slot Bunsen flame. These diagnostics, Cinema-Stereoscopic Particle Image Velocimetry and Orthogonal-Plane Cinema-Stereoscopic Particle Image Velocimetry, provided temporally resolved velocity and flame surface measurements in two- and three-dimensions with rates of up to 3 kHz and spatial resolutions as low as 280 mum. Using these measurements, the mechanisms with which turbulence generates flame surface area were studied. It was found that the previous concept that flame stretch is characterized by counter-rotating vortex pairs does not accurately describe real turbulence-flame interactions. Analysis of the experimental data showed that the straining of the flame surface is determined by coherent structures of fluid dynamic strain rate, while the wrinkling is caused by vortical structures. Furthermore, it was shown that the canonical vortex pair configuration is not an accurate reflection of the real interaction geometry. Hence, models developed based on this geometry are unlikely to be accurate. Previous models for the strain rate, curvature stretch rate, and turbulent burning velocity were evaluated. It was found that the previous models did not accurately predict the measured data for a variety of reasons: the assumed interaction geometries did not encompass enough possibilities to describe the possible effects of real turbulence, the turbulence was not properly characterized, and the transport of flame surface area was not always considered. New models therefore were developed that accurately reflect real turbulence-flame interactions and agree with the measured data. These can be implemented in Large Eddy Simulations to provide improved modeling of turbulence-flame interaction.

Chem Ed Compacts

ERIC Educational Resources Information Center

Wolf, Walter A., Ed.

1978-01-01

Presents four simple laboratory procedures for: preparation of organometallic compounds, a realistic qualitative organic analysis project, a computer program to plot potentiometric titration curves, and preparation of stereoscopic transparencies. (SL)

Resolving topographic detail on Venus by modeling complex Magellan altimetry echoes

NASA Technical Reports Server (NTRS)

Lovell, Amy J.; Schloerb, F. Peter; Mcgill, George E.

1993-01-01

Magellan's altimeter is providing some of the finest resolution topography of Venus achieved to date. Nevertheless, efforts continue to improve the topographic resolution whenever possible. One effort to this end is stereoscopic imaging, which provides topography at scales similar to that of the synthetic aperture radar (SAR). However, this technique requires two SAR images of the same site to be obtained and limits the utility of this method. In this paper, we present another method to resolve topographic features at scales smaller than that of an altimeter footprint, which is more globally applicable than the stereoscopic approach. Each pulse which is transmitted by Magellan's altimeter scatters from the planet and echoes to the receiver, delayed based on the distance between the spacecraft and each surface element. As resolved in time, each element of an altimetry echo represents the sum of all points on the surface which are equidistant from the spacecraft. Thus, individual returns, as a function of time, create an echo profile which may be used to derive properties of the surface, such as the scattering law or, in this case, the topography within the footprint. The Magellan project has derived some of this information by fitting model templates to radar echo profiles. The templates are calculated based on Hagfor's Law, which assumes a smooth, gently undulating surface. In most regions these templates provide a reasonable fit to the observed echo profile; however, in some cases the surface departs from these simple assumptions and more complex profiles are observed. Specifically, we note that sub-footprint topographic relief apparently has a strong effect on the shape of the echo profile. To demonstrate the effects of sub-resolution relief on echo profiles, we have calculated the echo shapes from a wide range of simple topographic models. At this point, our topographic models have emphasized surfaces where only two dominant elevations are contained within a footprint, such as graben, ridges, crater rims, and central features in impact craters.

Pancam Imaging of the Mars Exploration Rover Landing Sites in Gusev Crater and Meridiani Planum

NASA Technical Reports Server (NTRS)

Bell, J. F., III; Squyres, S. W.; Arvidson, R. E.; Arneson, H. M.; Bass, D.; Cabrol, N.; Calvin, W.; Farmer, J.; Farrand, W. H.

2004-01-01

The Mars Exploration Rovers carry four Panoramic Camera (Pancam) instruments (two per rover) that have obtained high resolution multispectral and stereoscopic images for studies of the geology, mineralogy, and surface and atmospheric physical properties at both rover landing sites. The Pancams are also providing significant mission support measurements for the rovers, including Sun-finding for rover navigation, hazard identification and digital terrain modeling to help guide long-term rover traverse decisions, high resolution imaging to help guide the selection of in situ sampling targets, and acquisition of education and public outreach imaging products.

Pixel-level tunable liquid crystal lenses for auto-stereoscopic display

NASA Astrophysics Data System (ADS)

Li, Kun; Robertson, Brian; Pivnenko, Mike; Chu, Daping; Zhou, Jiong; Yao, Jun

2014-02-01

Mobile video and gaming are now widely used, and delivery of a glass-free 3D experience is of both research and development interest. The key drawbacks of a conventional 3D display based on a static lenticular lenslet array and parallax barriers are low resolution, limited viewing angle and reduced brightness, mainly because of the need of multiple-pixels for each object point. This study describes the concept and performance of pixel-level cylindrical liquid crystal (LC) lenses, which are designed to steer light to the left and right eye sequentially to form stereo parallax. The width of the LC lenses can be as small as 20-30 μm, so that the associated auto-stereoscopic display will have the same resolution as the 2D display panel in use. Such a thin sheet of tunable LC lens array can be applied directly on existing mobile displays, and can deliver 3D viewing experience while maintaining 2D viewing capability. Transparent electrodes were laser patterned to achieve the single pixel lens resolution, and a high birefringent LC material was used to realise a large diffraction angle for a wide field of view. Simulation was carried out to model the intensity profile at the viewing plane and optimise the lens array based on the measured LC phase profile. The measured viewing angle and intensity profile were compared with the simulation results.

Generation of High Resolution Global DSM from ALOS PRISM

NASA Astrophysics Data System (ADS)

Takaku, J.; Tadono, T.; Tsutsui, K.

2014-04-01

Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM), one of onboard sensors carried on the Advanced Land Observing Satellite (ALOS), was designed to generate worldwide topographic data with its optical stereoscopic observation. The sensor consists of three independent panchromatic radiometers for viewing forward, nadir, and backward in 2.5 m ground resolution producing a triplet stereoscopic image along its track. The sensor had observed huge amount of stereo images all over the world during the mission life of the satellite from 2006 through 2011. We have semi-automatically processed Digital Surface Model (DSM) data with the image archives in some limited areas. The height accuracy of the dataset was estimated at less than 5 m (rms) from the evaluation with ground control points (GCPs) or reference DSMs derived from the Light Detection and Ranging (LiDAR). Then, we decided to process the global DSM datasets from all available archives of PRISM stereo images by the end of March 2016. This paper briefly reports on the latest processing algorithms for the global DSM datasets as well as their preliminary results on some test sites. The accuracies and error characteristics of datasets are analyzed and discussed on various fields by the comparison with existing global datasets such as Ice, Cloud, and land Elevation Satellite (ICESat) data and Shuttle Radar Topography Mission (SRTM) data, as well as the GCPs and the reference airborne LiDAR/DSM.

Project NANO (nanoscience and nanotechnology outreach): a STEM training program that brings SEM's and stereoscopes into high-school and middle-school classrooms

NASA Astrophysics Data System (ADS)

Cady, Sherry L.; Blok, Mikel; Grosse, Keith; Wells, Jennifer

2014-09-01

The program Project NANO (Nanoscience and Nanotechnology Outreach) enables middle and high school students to discover and research submicroscopic phenomena in a new and exciting way with the use of optical and scanning electron microscopes in the familiar surroundings of their middle or high school classrooms. Project NANO provides secondary level professional development workshops, support for classroom instruction and teacher curriculum development, and the means to deliver Project NANO toolkits (SEM, stereoscope, computer, supplies) to classrooms with Project NANO trained teachers. Evaluation surveys document the impact of the program on student's attitudes toward science and technology and on the learning outcomes for secondary level teachers. Project NANO workshops (offered for professional development credit) enable teachers to gain familiarity using and teaching with the SEM. Teachers also learn to integrate new content knowledge and skills into topic-driven, standards-based units of instruction specifically designed to support the development of students' higher order thinking skills that include problem solving and evidence-based thinking. The Project NANO management team includes a former university science faculty, two high school science teachers, and an educational researcher. To date, over 7500 students have experienced the impact of the Project NANO program, which provides an exciting and effective model for engaging students in the discovery of nanoscale phenomena and concepts in a fun and engaging way.

iCAVE: an open source tool for visualizing biomolecular networks in 3D, stereoscopic 3D and immersive 3D

PubMed Central

Liluashvili, Vaja; Kalayci, Selim; Fluder, Eugene; Wilson, Manda; Gabow, Aaron

2017-01-01

Abstract Visualizations of biomolecular networks assist in systems-level data exploration in many cellular processes. Data generated from high-throughput experiments increasingly inform these networks, yet current tools do not adequately scale with concomitant increase in their size and complexity. We present an open source software platform, interactome-CAVE (iCAVE), for visualizing large and complex biomolecular interaction networks in 3D. Users can explore networks (i) in 3D using a desktop, (ii) in stereoscopic 3D using 3D-vision glasses and a desktop, or (iii) in immersive 3D within a CAVE environment. iCAVE introduces 3D extensions of known 2D network layout, clustering, and edge-bundling algorithms, as well as new 3D network layout algorithms. Furthermore, users can simultaneously query several built-in databases within iCAVE for network generation or visualize their own networks (e.g., disease, drug, protein, metabolite). iCAVE has modular structure that allows rapid development by addition of algorithms, datasets, or features without affecting other parts of the code. Overall, iCAVE is the first freely available open source tool that enables 3D (optionally stereoscopic or immersive) visualizations of complex, dense, or multi-layered biomolecular networks. While primarily designed for researchers utilizing biomolecular networks, iCAVE can assist researchers in any field. PMID:28814063

Analysis of scene distortions in stereoscopic images due to the variation of the ideal viewing conditions

NASA Astrophysics Data System (ADS)

Viale, Alberto; Villa, Dario

2011-03-01

Recently stereoscopy has increased a lot its popularity and various technologies are spreading in theaters and homes allowing observation of stereoscopic images and movies, becoming affordable even for home users. However there are some golden rules that users should follow to ensure a better enjoyment of stereoscopic images, first of all the viewing condition should not be too different from the ideal ones, which were assumed during the production process. To allow the user to perceive stereo depth instead of a flat image, two different views of the same scene are shown to the subject, one is seen just through his left eye and the other just through the right one; the vision process is making the work of merging the two images in a virtual three-dimensional scene, giving to the user the perception of depth. The two images presented to the user were created, either from image synthesis or from more traditional techniques, following the rules of perspective. These rules need some boundary conditions to be explicit, such as eye separation, field of view, parallax distance, viewer position and orientation. In this paper we are interested in studying how the variation of the viewer position and orientation from the ideal ones expressed as specified parameters in the image creation process, is affecting the correctness of the reconstruction of the three-dimensional virtual scene.

Stereoscopic Three-Dimensional Neuroanatomy Lectures Enhance Neurosurgical Training: Prospective Comparison with Traditional Teaching.

PubMed

Clark, Anna D; Guilfoyle, Mathew R; Candy, Nicholas G; Budohoski, Karol P; Hofmann, Riikka; Barone, Damiano G; Santarius, Thomas; Kirollos, Ramez W; Trivedi, Rikin A

2017-12-01

Stereoscopic three-dimensional (3D) imaging is increasingly used in the teaching of neuroanatomy and although this is mainly aimed at undergraduate medical students, it has enormous potential for enhancing the training of neurosurgeons. This study aims to assess whether 3D lecturing is an effective method of enhancing the knowledge and confidence of neurosurgeons and how it compares with traditional two-dimensional (2D) lecturing and cadaveric training. Three separate teaching sessions for neurosurgical trainees were organized: 1) 2D course (2D lecture + cadaveric session), 2) 3D lecture alone, and 3) 3D course (3D lecture + cadaveric session). Before and after each session, delegates were asked to complete questionnaires containing questions relating to surgical experience, anatomic knowledge, confidence in performing procedures, and perceived value of 3D, 2D, and cadaveric teaching. Although both 2D and 3D lectures and courses were similarly effective at improving self-rated knowledge and understanding, the 3D lecture and course were associated with significantly greater gains in confidence reported by the delegates for performing a subfrontal approach and sylvian fissure dissection. Stereoscopic 3D lectures provide neurosurgical trainees with greater confidence for performing standard operative approaches and enhances the benefit of subsequent practical experience in developing technical skills in cadaveric dissection. Copyright © 2017. Published by Elsevier Inc.

Laser scanning stereomicroscopy for fast volumetric imaging with two-photon excitation and scanned Bessel beams

NASA Astrophysics Data System (ADS)

Yang, Yanlong; Zhou, Xing; Li, Runze; Van Horn, Mark; Peng, Tong; Lei, Ming; Wu, Di; Chen, Xun; Yao, Baoli; Ye, Tong

2015-03-01

Bessel beams have been used in many applications due to their unique optical properties of maintaining their intensity profiles unchanged during propagation. In imaging applications, Bessel beams have been successfully used to provide extended focuses for volumetric imaging and uniformed illumination plane in light-sheet microscopy. Coupled with two-photon excitation, Bessel beams have been successfully used in realizing fluorescence projected volumetric imaging. We demonstrated previously a stereoscopic solution-two-photon fluorescence stereomicroscopy (TPFSM)-for recovering the depth information in volumetric imaging with Bessel beams. In TPFSM, tilted Bessel beams were used to generate stereoscopic images on a laser scanning two-photon fluorescence microscope; upon post image processing we could successfully provide 3D perception of acquired volume images by wearing anaglyph 3D glasses. However, tilted Bessel beams were generated by shifting either an axicon or an objective laterally; the slow imaging speed and severe aberrations made it hard to use in real-time volume imaging. In this article, we report recent improvements of TPFSM with newly designed scanner and imaging software, which allows 3D stereoscopic imaging without moving any of the optical components on the setup. This improvement has dramatically improved focusing qualities and imaging speed so that the TPFSM can be performed potentially in real-time to provide 3D visualization in scattering media without post image processing.

iCAVE: an open source tool for visualizing biomolecular networks in 3D, stereoscopic 3D and immersive 3D.

PubMed

Liluashvili, Vaja; Kalayci, Selim; Fluder, Eugene; Wilson, Manda; Gabow, Aaron; Gümüs, Zeynep H

2017-08-01

Visualizations of biomolecular networks assist in systems-level data exploration in many cellular processes. Data generated from high-throughput experiments increasingly inform these networks, yet current tools do not adequately scale with concomitant increase in their size and complexity. We present an open source software platform, interactome-CAVE (iCAVE), for visualizing large and complex biomolecular interaction networks in 3D. Users can explore networks (i) in 3D using a desktop, (ii) in stereoscopic 3D using 3D-vision glasses and a desktop, or (iii) in immersive 3D within a CAVE environment. iCAVE introduces 3D extensions of known 2D network layout, clustering, and edge-bundling algorithms, as well as new 3D network layout algorithms. Furthermore, users can simultaneously query several built-in databases within iCAVE for network generation or visualize their own networks (e.g., disease, drug, protein, metabolite). iCAVE has modular structure that allows rapid development by addition of algorithms, datasets, or features without affecting other parts of the code. Overall, iCAVE is the first freely available open source tool that enables 3D (optionally stereoscopic or immersive) visualizations of complex, dense, or multi-layered biomolecular networks. While primarily designed for researchers utilizing biomolecular networks, iCAVE can assist researchers in any field. © The Authors 2017. Published by Oxford University Press.

Matching methods evaluation framework for stereoscopic breast x-ray images.

PubMed

Rousson, Johanna; Naudin, Mathieu; Marchessoux, Cédric

2016-01-01

Three-dimensional (3-D) imaging has been intensively studied in the past few decades. Depth information is an important added value of 3-D systems over two-dimensional systems. Special focuses were devoted to the development of stereo matching methods for the generation of disparity maps (i.e., depth information within a 3-D scene). Dedicated frameworks were designed to evaluate and rank the performance of different stereo matching methods but never considering x-ray medical images. Yet, 3-D x-ray acquisition systems and 3-D medical displays have already been introduced into the diagnostic market. To access the depth information within x-ray stereoscopic images, computing accurate disparity maps is essential. We aimed at developing a framework dedicated to x-ray stereoscopic breast images used to evaluate and rank several stereo matching methods. A multiresolution pyramid optimization approach was integrated to the framework to increase the accuracy and the efficiency of the stereo matching techniques. Finally, a metric was designed to score the results of the stereo matching compared with the ground truth. Eight methods were evaluated and four of them [locally scaled sum of absolute differences (LSAD), zero mean sum of absolute differences, zero mean sum of squared differences, and locally scaled mean sum of squared differences] appeared to perform equally good with an average error score of 0.04 (0 is the perfect matching). LSAD was selected for generating the disparity maps.

Deep-level stereoscopic multiple traps of acoustic vortices

NASA Astrophysics Data System (ADS)

Li, Yuzhi; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong

2017-04-01

Based on the radiation pattern of a planar piston transducer, the mechanisms underlying the generation of axially controllable deep-level stereoscopic multiple traps of acoustic vortices (AV) using sparse directional sources were proposed with explicit formulae. Numerical simulations for the axial and cross-sectional distributions of acoustic pressure and phase were conducted for various ka (product of the wave number and the radius of transducer) values at the frequency of 1 MHz. It was demonstrated that, for bigger ka, besides the main-AV (M-AV) generated by the main lobes of the sources, cone-shaped side-AV (S-AV) produced by the side lobes were closer to the source plane at a relatively lower pressure. Corresponding to the radiation angles of pressure nulls between the main lobe and the side lobes of the sources, vortex valleys with nearly pressure zero could be generated on the central axis to form multiple traps, based on Gor'kov potential theory. The number and locations of vortex valleys could be controlled accurately by the adjustment of ka. With the established eight-source AV generation system, the existence of the axially controllable multiple traps was verified by the measured M-AV and S-AVs as well as the corresponding vortex valleys. The favorable results provided the feasibility of deep-level stereoscopic control of AV and suggested potential application of multiple traps for particle manipulation in the area of biomedical engineering.

Clinically Normal Stereopsis Does Not Ensure a Performance Benefit from Stereoscopic 3D Depth Cues

NASA Astrophysics Data System (ADS)

McIntire, John P.; Havig, Paul R.; Harrington, Lawrence K.; Wright, Steve T.; Watamaniuk, Scott N. J.; Heft, Eric L.

2014-09-01

To investigate the effect of manipulating disparity on task performance and viewing comfort, twelve participants were tested on a virtual object precision placement task while viewing a stereoscopic 3D (S3D) display. All participants had normal or corrected-to-normal visual acuity, passed the Titmus stereovision clinical test, and demonstrated normal binocular function, including phorias and binocular fusion ranges. Each participant completed six experimental sessions with different maximum binocular disparity limits. The results for ten of the twelve participants were generally as expected, demonstrating a large performance advantage when S3D cues were provided. The sessions with the larger disparity limits typically resulted in the best performance, and the sessions with no S3D cues the poorest performance. However, one participant demonstrated poorer performance in sessions with smaller disparity limits but improved performance in sessions with the larger disparity limits. Another participant's performance declined whenever any S3D cues were provided. Follow-up testing suggested that the phenomenon of pseudo-stereoanomaly may account for one viewer's atypical performance, while the phenomenon of stereoanomaly might account for the other. Overall, the results demonstrate that a subset of viewers with clinically normal binocular and stereoscopic vision may have difficulty performing depth-related tasks on S3D displays. The possibility of the vergence-accommodation conflict contributing to individual performance differences is also discussed.

Parallax Player: a stereoscopic format converter

NASA Astrophysics Data System (ADS)

Feldman, Mark H.; Lipton, Lenny

2003-05-01

The Parallax Player is a software application that is, in essence, a stereoscopic format converter. Various formats may be inputted and outputted. In addition to being able to take any one of a wide variety of different formats and play them back on many different kinds of PCs and display screens. The Parallax Player has built into it the capability to produce ersatz stereo from a planar still or movie image. The player handles two basic forms of digital content - still images, and movies. It is assumed that all data is digital, either created by means of a photographic film process and later digitized, or directly captured or authored in a digital form. In its current implementation, running on a number of Windows Operating Systems, The Parallax Player reads in a broad selection of contemporary file formats.

Disparity modifications and the emotional effects of stereoscopic images

NASA Astrophysics Data System (ADS)

Kawai, Takashi; Atsuta, Daiki; Tomiyama, Yuya; Kim, Sanghyun; Morikawa, Hiroyuki; Mitsuya, Reiko; Häkkinen, Jukka

2014-03-01

This paper describes a study that focuses on disparity changes in emotional scenes of stereoscopic (3D) images, in which an examination of the effects on pleasant and arousal was carried out by adding binocular disparity to 2D images that evoke specific emotions, and applying disparity modification based on the disparity analysis of famous 3D movies. From the results of the experiment, for pleasant, a significant difference was found only for the main effect of the emotions. On the other hand, for arousal, there was a trend of increasing the evaluation values in the order 2D condition, 3D condition and 3D condition applied the disparity modification for happiness, surprise, and fear. This suggests the possibility that binocular disparity and the modification affect arousal.

Real-time skin feature identification in a time-sequential video stream

NASA Astrophysics Data System (ADS)

Kramberger, Iztok

2005-04-01

Skin color can be an important feature when tracking skin-colored objects. Particularly this is the case for computer-vision-based human-computer interfaces (HCI). Humans have a highly developed feeling of space and, therefore, it is reasonable to support this within intelligent HCI, where the importance of augmented reality can be foreseen. Joining human-like interaction techniques within multimodal HCI could, or will, gain a feature for modern mobile telecommunication devices. On the other hand, real-time processing plays an important role in achieving more natural and physically intuitive ways of human-machine interaction. The main scope of this work is the development of a stereoscopic computer-vision hardware-accelerated framework for real-time skin feature identification in the sense of a single-pass image segmentation process. The hardware-accelerated preprocessing stage is presented with the purpose of color and spatial filtering, where the skin color model within the hue-saturation-value (HSV) color space is given with a polyhedron of threshold values representing the basis of the filter model. An adaptive filter management unit is suggested to achieve better segmentation results. This enables the adoption of filter parameters to the current scene conditions in an adaptive way. Implementation of the suggested hardware structure is given at the level of filed programmable system level integrated circuit (FPSLIC) devices using an embedded microcontroller as their main feature. A stereoscopic clue is achieved using a time-sequential video stream, but this shows no difference for real-time processing requirements in terms of hardware complexity. The experimental results for the hardware-accelerated preprocessing stage are given by efficiency estimation of the presented hardware structure using a simple motion-detection algorithm based on a binary function.

SUN-TO-EARTH CHARACTERISTICS OF THE 2012 JULY 12 CORONAL MASS EJECTION AND ASSOCIATED GEO-EFFECTIVENESS

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

Hu, Huidong; Liu, Ying D.; Wang, Rui

We analyze multi-spacecraft observations associated with the 2012 July 12 coronal mass ejection (CME), covering the source region on the Sun from the Solar Dynamics Observatory , stereoscopic imaging observations from the Solar Terrestrial Relations Observatory ( STEREO ), magnetic field characteristics from Mercury Surface, Space Environment, Geochemistry, and Ranging ( MESSENGER ), and type II radio burst and in situ measurements from Wind . A triangulation method based on STEREO stereoscopic observations is employed to determine the kinematics of the CME, and the outcome is compared with the results derived from the type II radio burst using a solarmore » wind electron density model. A Grad–Shafranov technique is applied to Wind in situ data to reconstruct the flux-rope structure and compare it with the observations of the solar source region, which helps in understanding the geo-effectiveness associated with the CME structure. Our conclusions are as follows: (1) the CME undergoes an impulsive acceleration, a rapid deceleration before reaching MESSENGER , and then a gradual deceleration out to 1 au, which should be considered in CME kinematics models; (2) the type II radio burst was probably produced from a high-density interaction region between the CME-driven shock and a nearby streamer or from the shock flank with lower heights, which implies uncertainties in the determination of CME kinematics using solely type II radio bursts; (3) the flux-rope orientation and chirality deduced from in situ reconstructions at Wind agree with those obtained from solar source observations; (4) the prolonged southward magnetic field near the Earth is mainly from the axial component of the largely southward inclined flux rope, which indicates the importance of predicting both the flux-rope orientation and magnetic field components in geomagnetic activity forecasting.« less

Extratropical Cyclone

Atmospheric Science Data Center

2013-04-16

... using data from multiple MISR cameras within automated computer processing algorithms. The stereoscopic algorithms used to generate ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

Digital Elevation Models of Greenland based on combined radar and laser altimetry as well as high-resolution stereoscopic imagery

NASA Astrophysics Data System (ADS)

Levinsen, J. F.; Smith, B. E.; Sandberg Sorensen, L.; Khvorostovsky, K.; Simonsen, S. B.; Forsberg, R.

2015-12-01

A number of Digital Elevation Models (DEMs) of Greenland exist, each of which are applicable for different purposes. This study presents two such DEMs: One developed by merging contemporary radar and laser altimeter data, and one derived from high-resolution stereoscopic imagery. All products are made freely available. The former DEM covers the entire Greenland. It is specific to the year 2010, providing it with an advantage over previous models suffering from either a reduced spatial/ temporal data coverage or errors from surface elevation changes (SEC) occurring during data acquisition. Radar data are acquired with Envisat and CryoSat-2, and laser data with the Ice, Cloud, and land Elevation Satellite, the Land, Vegetation, and Ice Sensor, and the Airborne Topographic Mapper. Correcting radar data for errors from slope effects and surface penetration of the echoes, and merging these with laser data, yields a DEM capable of resolving both surface depressions as well as topographic features at higher altitudes. The spatial resolution is 2 x 2 km, making the DEM ideal for application in surface mass balance studies, SEC detection from radar altimetry, or for correcting such data for slope-induced errors. The other DEM is developed in a pilot study building the expertise to map all ice-free parts of Greenland. The work combines WorldView-2 and -3 as well as GeoEye1 imagery from 2014 and 2015 over the Disko, Narsaq, Tassilaq, and Zackenberg regions. The novelty of the work is the determination of the product specifications after elaborate discussions with interested parties from government institutions, the tourist industry, etc. Thus, a 10 m DEM, 1.5 m orthophotos, and vector maps are produced. This opens to the possibility of using orthophotos with up-to-date contour lines or for deriving updated coastlines to aid, e.g., emergency management. This allows for a product development directly in line with the needs of parties with specific interests in Greenland.

Lambert-Amery

Atmospheric Science Data Center

2013-04-16

... exhibiting insufficient spatial contrast for stereoscopic retrieval are shown in dark gray. Clouds are apparent as a result of their ... their distributions, and retrieval of their heights provide information that will help to reduce this uncertainty. The Multi-angle ...

Achromatized transmission-type holographic screen for a multiview stereoscopic image system

NASA Astrophysics Data System (ADS)

Hwang, Seon-Ho; Bobrinev, V. I.; Son, Jung-Young; Shestak, S. A.; Jeon, Hyung-Wook

1997-09-01

The main drawback of the use of transmission-type holographic screens is poor color reproduction caused by their high spectral dispersion. For overcoming this drawback, a long, narrow diffusing slit is used as an object when recording the screen. The necessary size and position of the slit relative to the photoplate and to the recording and reconstruction beams are determined by the phase relations of the beams. By use of the slit, holographic screens of 30 cm 40 cm are recorded with a diverging reference beam and are used to display a multiview full-color stereoscopic image. The images displayed on the screen show no sign of color separation except near the edges of the screen. The image brightness on the screen is high enough that it can be watched in a normally illuminated room.

Head-coupled remote stereoscopic camera system for telepresence applications

NASA Astrophysics Data System (ADS)

Bolas, Mark T.; Fisher, Scott S.

1990-09-01

The Virtual Environment Workstation Project (VIEW) at NASA's Ames Research Center has developed a remotely controlled stereoscopic camera system that can be used for telepresence research and as a tool to develop and evaluate configurations for head-coupled visual systems associated with space station telerobots and remote manipulation robotic arms. The prototype camera system consists of two lightweight CCD video cameras mounted on a computer controlled platform that provides real-time pan, tilt, and roll control of the camera system in coordination with head position transmitted from the user. This paper provides an overall system description focused on the design and implementation of the camera and platform hardware configuration and the development of control software. Results of preliminary performance evaluations are reported with emphasis on engineering and mechanical design issues and discussion of related psychophysiological effects and objectives.

A versatile stereoscopic visual display system for vestibular and oculomotor research.

PubMed

Kramer, P D; Roberts, D C; Shelhamer, M; Zee, D S

1998-01-01

Testing of the vestibular system requires a vestibular stimulus (motion) and/or a visual stimulus. We have developed a versatile, low cost, stereoscopic visual display system, using "virtual reality" (VR) technology. The display system can produce images for each eye that correspond to targets at any virtual distance relative to the subject, and so require the appropriate ocular vergence. We elicited smooth pursuit, "stare" optokinetic nystagmus (OKN) and after-nystagmus (OKAN), vergence for targets at various distances, and short-term adaptation of the vestibulo-ocular reflex (VOR), using both conventional methods and the stereoscopic display. Pursuit, OKN, and OKAN were comparable with both methods. When used with a vestibular stimulus, VR induced appropriate adaptive changes of the phase and gain of the angular VOR. In addition, using the VR display system and a human linear acceleration sled, we adapted the phase of the linear VOR. The VR-based stimulus system not only offers an alternative to more cumbersome means of stimulating the visual system in vestibular experiments, it also can produce visual stimuli that would otherwise be impractical or impossible. Our techniques provide images without the latencies encountered in most VR systems. Its inherent versatility allows it to be useful in several different types of experiments, and because it is software driven it can be quickly adapted to provide a new stimulus. These two factors allow VR to provide considerable savings in time and money, as well as flexibility in developing experimental paradigms.

Many-core computing for space-based stereoscopic imaging

NASA Astrophysics Data System (ADS)

McCall, Paul; Torres, Gildo; LeGrand, Keith; Adjouadi, Malek; Liu, Chen; Darling, Jacob; Pernicka, Henry

The potential benefits of using parallel computing in real-time visual-based satellite proximity operations missions are investigated. Improvements in performance and relative navigation solutions over single thread systems can be achieved through multi- and many-core computing. Stochastic relative orbit determination methods benefit from the higher measurement frequencies, allowing them to more accurately determine the associated statistical properties of the relative orbital elements. More accurate orbit determination can lead to reduced fuel consumption and extended mission capabilities and duration. Inherent to the process of stereoscopic image processing is the difficulty of loading, managing, parsing, and evaluating large amounts of data efficiently, which may result in delays or highly time consuming processes for single (or few) processor systems or platforms. In this research we utilize the Single-Chip Cloud Computer (SCC), a fully programmable 48-core experimental processor, created by Intel Labs as a platform for many-core software research, provided with a high-speed on-chip network for sharing information along with advanced power management technologies and support for message-passing. The results from utilizing the SCC platform for the stereoscopic image processing application are presented in the form of Performance, Power, Energy, and Energy-Delay-Product (EDP) metrics. Also, a comparison between the SCC results and those obtained from executing the same application on a commercial PC are presented, showing the potential benefits of utilizing the SCC in particular, and any many-core platforms in general for real-time processing of visual-based satellite proximity operations missions.

Photogrammetric application of viking orbital photography

USGS Publications Warehouse

Wu, S.S.C.; Elassal, A.A.; Jordan, R.; Schafer, F.J.

1982-01-01

Special techniques are described for the photogrammetric compilation of topographic maps and profiles from stereoscopic photographs taken by the two Viking Orbiter spacecraft. These techniques were developed because the extremely narrow field of view of the Viking cameras precludes compilation by conventional photogrammetric methods. The techniques adjust for internal consistency the Supplementary Experiment Data Record (SEDR-the record of spacecraft orientation when photographs were taken) and the computation of geometric orientation parameters of the stereo models. A series of contour maps of Mars is being compiled by these new methods using a wide variety of Viking Orbiter photographs, to provide the planetary research community with topographic information. ?? 1982.

Photogrammetric Archaeological Survey with UAV

NASA Astrophysics Data System (ADS)

Mouget, A.; Lucet, G.

2014-05-01

This document describes a way to obtain various photogrammetric products from aerial photograph using a drone. The aim of the project was to develop a methodology to obtain information for the study of the architecture of pre-Columbian archaeological sites in Mexico combining the manoeuvrability and low cost of a drone with the accuracy of the results of the open source photogrammetric MicMac software. It presents the UAV and the camera used, explains how to manipulate it to carry out stereoscopic photographs, the flight and camera parameters chosen, the treatments performed to obtain orthophotos and 3D models with a centimetric resolution, and finally outlines the quality of the results.

Limits on an energy dependence of the speed of light from a flare of the active galaxy PKS 2155-304.

PubMed

Aharonian, F; Akhperjanian, A G; Barres de Almeida, U; Bazer-Bachi, A R; Becherini, Y; Behera, B; Beilicke, M; Benbow, W; Bernlöhr, K; Boisson, C; Bochow, A; Borrel, V; Braun, I; Brion, E; Brucker, J; Brun, P; Bühler, R; Bulik, T; Büsching, I; Boutelier, T; Carrigan, S; Chadwick, P M; Charbonnier, A; Chaves, R C G; Chounet, L-M; Clapson, A C; Coignet, G; Costamante, L; Dalton, M; Degrange, B; Deil, C; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubois, F; Dubus, G; Dyks, J; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Füssling, M; Gabici, S; Gallant, Y A; Gérard, L; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; de Jager, O C; Jung, I; Katarzyński, K; Kaufmann, S; Kendziorra, E; Kerschhaggl, M; Khangulyan, D; Khélifi, B; Keogh, D; Komin, Nu; Kosack, K; Lamanna, G; Lenain, J-P; Lohse, T; Marandon, V; Martin, J M; Martineau-Huynh, O; Marcowith, A; Maurin, D; McComb, T J L; Medina, C; Moderski, R; Moulin, E; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; de Oña Wilhelmi, E; Orford, K J; Osborne, J L; Ostrowski, M; Panter, M; Pedaletti, G; Pelletier, G; Petrucci, P-O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raubenheimer, B C; Raue, M; Rayner, S M; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Ruppel, J; Sahakian, V; Santangelo, A; Schlickeiser, R; Schöck, F M; Schröder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Skilton, J L; Sol, H; Spangler, D; Stawarz, Ł; Steenkamp, R; Stegmann, C; Superina, G; Tam, P H; Tavernet, J-P; Terrier, R; Tibolla, O; van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

2008-10-24

In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System observations of the exceptional very high energy flare of the active galaxy PKS 2155-304 on 28 July 2006 is presented. Since no significant time lag is found, lower limits on the energy scale of speed of light modifications are derived.

Extraction and textural characterization of above-ground areas from aerial stereo pairs: a quality assessment

NASA Astrophysics Data System (ADS)

Baillard, C.; Dissard, O.; Jamet, O.; Maître, H.

Above-ground analysis is a key point to the reconstruction of urban scenes, but it is a difficult task because of the diversity of the involved objects. We propose a new method to above-ground extraction from an aerial stereo pair, which does not require any assumption about object shape or nature. A Digital Surface Model is first produced by a stereoscopic matching stage preserving discontinuities, and then processed by a region-based Markovian classification algorithm. The produced above-ground areas are finally characterized as man-made or natural according to the grey level information. The quality of the results is assessed and discussed.

Unsteady flow in the nasal cavity with high flow therapy measured by stereoscopic PIV

NASA Astrophysics Data System (ADS)

Spence, C. J. T.; Buchmann, N. A.; Jermy, M. C.

2012-03-01

Nasal high flow (NHF) cannulae are used to deliver heated and humidified air to patients at steady flows ranging from 5 to 50 l/min. In this study, the flow velocities in the nasal cavity across the complete respiratory cycle during natural breathing and with NHF has been mapped in vitro using time-resolved stereoscopic particle image velocimetry (SPIV). An anatomically accurate silicone resin model of a complete human nasal cavity was constructed using CT scan data and rapid prototyping. Physiological breathing waveforms were reproduced in vitro using Reynolds and Womersley number matching and a piston pump driven by a ball screw and stepper motor. The flow pattern in the nasal cavity with NHF was found to differ significantly from natural breathing. Velocities of 2.4 and 3.3 ms-1 occurred in the nasal valve during natural breathing at peak expiration and inspiration, respectively; however, on expiration, the maximum velocity of 3.8 ms-1 occurred in the nasopharynx. At a cannula flow rate of 30 l/min, maximal velocities of 13.6 and 16.5 ms-1 at peak expiration and inspiration, respectively, were both located in the cannula jet within the nasal valve. Results are presented that suggest the quasi-steady flow assumption is invalid in the nasal cavity during natural breathing; however, it was valid with NHF. Cannula flow has been found to continuously flush the nasopharyngeal dead space, which may enhance carbon dioxide removal and increase oxygen fraction.

Integrated system for point cloud reconstruction and simulated brain shift validation using tracked surgical microscope

NASA Astrophysics Data System (ADS)

Yang, Xiaochen; Clements, Logan W.; Luo, Ma; Narasimhan, Saramati; Thompson, Reid C.; Dawant, Benoit M.; Miga, Michael I.

2017-03-01

Intra-operative soft tissue deformation, referred to as brain shift, compromises the application of current imageguided surgery (IGS) navigation systems in neurosurgery. A computational model driven by sparse data has been used as a cost effective method to compensate for cortical surface and volumetric displacements. Stereoscopic microscopes and laser range scanners (LRS) are the two most investigated sparse intra-operative imaging modalities for driving these systems. However, integrating these devices in the clinical workflow to facilitate development and evaluation requires developing systems that easily permit data acquisition and processing. In this work we present a mock environment developed to acquire stereo images from a tracked operating microscope and to reconstruct 3D point clouds from these images. A reconstruction error of 1 mm is estimated by using a phantom with a known geometry and independently measured deformation extent. The microscope is tracked via an attached tracking rigid body that facilitates the recording of the position of the microscope via a commercial optical tracking system as it moves during the procedure. Point clouds, reconstructed under different microscope positions, are registered into the same space in order to compute the feature displacements. Using our mock craniotomy device, realistic cortical deformations are generated. Our experimental results report approximately 2mm average displacement error compared with the optical tracking system. These results demonstrate the practicality of using tracked stereoscopic microscope as an alternative to LRS to collect sufficient intraoperative information for brain shift correction.

Virtual tape measure for the operating microscope: system specifications and performance evaluation.

PubMed

Kim, M Y; Drake, J M; Milgram, P

2000-01-01

The Virtual Tape Measure for the Operating Microscope (VTMOM) was created to assist surgeons in making accurate 3D measurements of anatomical structures seen in the surgical field under the operating microscope. The VTMOM employs augmented reality techniques by combining stereoscopic video images with stereoscopic computer graphics, and functions by relying on an operator's ability to align a 3D graphic pointer, which serves as the end-point of the virtual tape measure, with designated locations on the anatomical structure being measured. The VTMOM was evaluated for its baseline and application performances as well as its application efficacy. Baseline performance was determined by measuring the mean error (bias) and standard deviation of error (imprecision) in measurements of non-anatomical objects. Application performance was determined by comparing the error in measuring the dimensions of aneurysm models with and without the VTMOM. Application efficacy was determined by comparing the error in selecting the appropriate aneurysm clip size with and without the VTMOM. Baseline performance indicated a bias of 0.3 mm and an imprecision of 0.6 mm. Application bias was 3.8 mm and imprecision was 2.8 mm for aneurysm diameter. The VTMOM did not improve aneurysm clip size selection accuracy. The VTMOM is a potentially accurate tool for use under the operating microscope. However, its performance when measuring anatomical objects is highly dependent on complex visual features of the object surfaces. Copyright 2000 Wiley-Liss, Inc.

Virtual 3-dimensional preoperative planning with the dextroscope for excision of a 4th ventricular ependymoma.

PubMed

Anil, S M; Kato, Y; Hayakawa, M; Yoshida, K; Nagahisha, S; Kanno, T

2007-04-01

Advances in computer imaging and technology have facilitated enhancement in surgical planning with a 3-dimensional model of the surgical plan of action utilizing advanced visualization tools in order to plan individual interactive operations with the aid of the dextroscope. This provides a proper 3-dimensional imaging insight to the pathological anatomy and sets a new dimension in collaboration for training and education. The case of a seventeen-year-old female, being operated with the aid of a preoperative 3-dimensional virtual reality planning and the practical application of the neurosurgical operation, is presented. This young lady presented with a two-year history of recurrent episodes of severe, global, throbbing headache with episodes of projectile vomiting associated with shoulder pain which progressively worsened. She had no obvious neurological deficits on clinical examination. CT and MRI showed a contrast-enhancing midline posterior fossa space-occupying lesion. Utilizing virtual imaging technology with the aid of a dextroscope which generates stereoscopic images, a 3-dimensional image was produced with the CT and MRI images. A preoperative planning for excision of the lesion was made and a real-time 3-dimensional volume was produced and surgical planning with the dextroscope was made and the lesion excised. Virtual reality has brought new proportions in 3-dimensional planning and management of various complex neuroanatomical problems that are faced during various operations. Integration of 3-dimensional imaging with stereoscopic vision makes understanding the complex anatomy easier and helps improve decision making in patient management.

Using Stereo Vision to Support the Automated Analysis of Surveillance Videos

NASA Astrophysics Data System (ADS)

Menze, M.; Muhle, D.

2012-07-01

Video surveillance systems are no longer a collection of independent cameras, manually controlled by human operators. Instead, smart sensor networks are developed, able to fulfil certain tasks on their own and thus supporting security personnel by automated analyses. One well-known task is the derivation of people's positions on a given ground plane from monocular video footage. An improved accuracy for the ground position as well as a more detailed representation of single salient people can be expected from a stereoscopic processing of overlapping views. Related work mostly relies on dedicated stereo devices or camera pairs with a small baseline. While this set-up is helpful for the essential step of image matching, the high accuracy potential of a wide baseline and the according good intersection geometry is not utilised. In this paper we present a stereoscopic approach, working on overlapping views of standard pan-tilt-zoom cameras which can easily be generated for arbitrary points of interest by an appropriate reconfiguration of parts of a sensor network. Experiments are conducted on realistic surveillance footage to show the potential of the suggested approach and to investigate the influence of different baselines on the quality of the derived surface model. Promising estimations of people's position and height are retrieved. Although standard matching approaches show helpful results, future work will incorporate temporal dependencies available from image sequences in order to reduce computational effort and improve the derived level of detail.

Large Smoke Plumes, Alberta Canada

Atmospheric Science Data Center

2016-12-30

... has adverse impacts on human health.   These data were acquired during Terra orbit 87148. The stereoscopic analysis was ... software tool, which is publicly available through the Open Channel Foundation at: https://www.openchannelsoftware.com/projects/MINX ...

Stereo Pair, Pasadena, California

NASA Image and Video Library

2000-03-10

This stereoscopic image pair is a perspective view that shows the western part of the city of Pasadena, California, looking north toward the San Gabriel Mountains. Portions of the cities of Altadena and La Canada Flintridge are also shown.

SRTM Stereo Pair: Bhuj, India, Two Weeks After Earthquake

NASA Image and Video Library

2001-04-05

On January 26, 2001, the city of Bhuj suffered the most deadly earthquake in India history. This stereoscopic image was generated from NASA Landsat satellite and data from Shuttle Radar Topography Mission SRTM.

Stereo Measurements from Satellites

NASA Technical Reports Server (NTRS)

Adler, R.

1982-01-01

The papers in this presentation include: 1) 'Stereographic Observations from Geosynchronous Satellites: An Important New Tool for the Atmospheric Sciences'; 2) 'Thunderstorm Cloud Top Ascent Rates Determined from Stereoscopic Satellite Observations'; 3) 'Artificial Stereo Presentation of Meteorological Data Fields'.

Stereo Pair, Honolulu, Oahu

NASA Image and Video Library

2000-03-10

Honolulu, on the island of Oahu, is a large and growing urban area. This stereoscopic image pair, combining a Landsat image with topography measured by NASA Shuttle Radar Topography Mission SRTM, shows how topography controls the urban pattern.

Africa in SRTM 3-D, Anaglyph of Shaded Relief

NASA Image and Video Library

2004-06-17

This stereoscopic shaded relief image from NASA Shuttle Radar Topography Mission shows Africa topography. Also shown are Madagascar, the Arabian Peninsula, and other adjacent regions. 3D glasses are necessary to view this image.

Three-Dimensional Dynamic Deformation Measurements Using Stereoscopic Imaging and Digital Speckle Photography

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

Prentice, H. J.; Proud, W. G.

2006-07-28

A technique has been developed to determine experimentally the three-dimensional displacement field on the rear surface of a dynamically deforming plate. The technique combines speckle analysis with stereoscopy, using a modified angular-lens method: this incorporates split-frame photography and a simple method by which the effective lens separation can be adjusted and calibrated in situ. Whilst several analytical models exist to predict deformation in extended or semi-infinite targets, the non-trivial nature of the wave interactions complicates the generation and development of analytical models for targets of finite depth. By interrogating specimens experimentally to acquire three-dimensional strain data points, both analytical andmore » numerical model predictions can be verified more rigorously. The technique is applied to the quasi-static deformation of a rubber sheet and dynamically to Mild Steel sheets of various thicknesses.« less

Topography of the Overriding Plate During Progressive Subduction: A Dynamic Model to Explain Forearc Subsidence

NASA Astrophysics Data System (ADS)

Chen, Zhihao; Schellart, Wouter P.; Duarte, João. C.; Strak, Vincent

2017-10-01

Overriding plate topography provides constraints on subduction zone geodynamics. We investigate its evolution using fully dynamic laboratory models of subduction with techniques of stereoscopic photogrammetry and particle image velocimetry. Model results show that the topography is characterized by an area of forearc dynamic subsidence, with a magnitude scaling to 1.44-3.97 km in nature, and a local topographic high between the forearc subsided region and the trench. These topographic features rapidly develop during the slab free-sinking phase and gradually decrease during the steady state slab rollback phase. We propose that they result from the variation of the vertical component of the trench suction force along the subduction zone interface, which gradually increases with depth and results from the gradual slab steepening during the initial transient slab sinking phase. The downward mantle flow in the nose of the mantle wedge plays a minor role in driving forearc subsidence.

Computer vision research with new imaging technology

NASA Astrophysics Data System (ADS)

Hou, Guangqi; Liu, Fei; Sun, Zhenan

2015-12-01

Light field imaging is capable of capturing dense multi-view 2D images in one snapshot, which record both intensity values and directions of rays simultaneously. As an emerging 3D device, the light field camera has been widely used in digital refocusing, depth estimation, stereoscopic display, etc. Traditional multi-view stereo (MVS) methods only perform well on strongly texture surfaces, but the depth map contains numerous holes and large ambiguities on textureless or low-textured regions. In this paper, we exploit the light field imaging technology on 3D face modeling in computer vision. Based on a 3D morphable model, we estimate the pose parameters from facial feature points. Then the depth map is estimated through the epipolar plane images (EPIs) method. At last, the high quality 3D face model is exactly recovered via the fusing strategy. We evaluate the effectiveness and robustness on face images captured by a light field camera with different poses.

MISR Observes Southern California Wildfires

Atmospheric Science Data Center

2016-12-30

... of the smoke is confined to the local area.   These data were acquired during Terra orbit 87818. The stereoscopic analysis was ... software tool, which is publicly available through the Open Channel Foundation at: https://www.openchannelsoftware.com/projects/MINX ...

Mars Odyssey Seen by Mars Global Surveyor 3-D

NASA Image and Video Library

2005-05-19

This stereoscopic picture of NASA Mars Odyssey spacecraft was created from two views of that spacecraft taken by the Mars Orbiter Camera on NASA Mars Global Surveyor. 3D glasses are necessary to view this image.

Chemistry Notes.

ERIC Educational Resources Information Center

School Science Review, 1983

1983-01-01

Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

Telescience testbed experiments for biomedical studies: fertilization potential recording of amphibian eggs using tele-manipulation under stereoscopic vision.

PubMed

Watanabe, S; Tanaka, M; Wada, Y; Suzuki, H; Takagi, S; Mori, S; Fukai, K; Kanazawa, Y; Takagi, M; Hirakawa, K; Ogasawara, K; Tsumura, K; Ogawa, K; Matsumoto, K; Nagaoka, S; Suzuki, T; Shimura, D; Yamashita, M; Nishio, S

1994-07-01

The telescience testbed experiments were carried out to test and investigate the tele-manipulation techniques in the intracellular potential recording of amphibian eggs. Implementation of telescience testbed was set up in the two separated laboratories of the Tsukuba Space center of NASDA, which were connected by tele-communication links. Manipulators respective for a microelectrode and a sample stage of microscope were moved by computers, of which command signals were transmitted from a computer in a remote control room. The computer in the control room was operated by an investigator (PI) who controlled the movement of each manipulator remotely. A stereoscopic vision of the microscope image were prepared by using a head mounted display (HMD) and were indispensable to the intracellular single cell recording. The fertilization potential of amphibian eggs was successfully obtained through the remote operating system.

Stereoscopic augmented reality with pseudo-realistic global illumination effects

NASA Astrophysics Data System (ADS)

de Sorbier, Francois; Saito, Hideo

2014-03-01

Recently, augmented reality has become very popular and has appeared in our daily life with gaming, guiding systems or mobile phone applications. However, inserting object in such a way their appearance seems natural is still an issue, especially in an unknown environment. This paper presents a framework that demonstrates the capabilities of Kinect for convincing augmented reality in an unknown environment. Rather than pre-computing a reconstruction of the scene like proposed by most of the previous method, we propose a dynamic capture of the scene that allows adapting to live changes of the environment. Our approach, based on the update of an environment map, can also detect the position of the light sources. Combining information from the environment map, the light sources and the camera tracking, we can display virtual objects using stereoscopic devices with global illumination effects such as diffuse and mirror reflections, refractions and shadows in real time.

On-demand stereoscopic 3D displays for avionic and military applications

NASA Astrophysics Data System (ADS)

Sarma, Kalluri; Lu, Kanghua; Larson, Brent; Schmidt, John; Cupero, Frank

2010-04-01

High speed AM LCD flat panels are evaluated for use in Field Sequential Stereoscopic (FSS) 3D displays for military and avionic applications. A 120 Hz AM LCD is used in field-sequential mode for constructing eyewear-based as well as autostereoscopic 3D display demonstrators for test and evaluation. The COTS eyewear-based system uses shutter glasses to control left-eye/right-eye images. The autostereoscopic system uses a custom backlight to generate illuminating pupils for left and right eyes. It is driven in synchronization with the images on the LCD. Both displays provide 3D effect in full-color and full-resolution in the AM LCD flat panel. We have realized luminance greater than 200 fL in 3D mode with the autostereoscopic system for sunlight readability. The characterization results and performance attributes of both systems are described.

Using a commodity high-definition television for collaborative structural biology

PubMed Central

Yennamalli, Ragothaman; Arangarasan, Raj; Bryden, Aaron; Gleicher, Michael; Phillips, George N.

2014-01-01

Visualization of protein structures using stereoscopic systems is frequently needed by structural biologists working to understand a protein’s structure–function relationships. Often several scientists are working as a team and need simultaneous interaction with each other and the graphics representations. Most existing molecular visualization tools support single-user tasks, which are not suitable for a collaborative group. Expensive caves, domes or geowalls have been developed, but the availability and low cost of high-definition televisions (HDTVs) and game controllers in the commodity entertainment market provide an economically attractive option to achieve a collaborative environment. This paper describes a low-cost environment, using standard consumer game controllers and commercially available stereoscopic HDTV monitors with appropriate signal converters for structural biology collaborations employing existing binary distributions of commonly used software packages like Coot, PyMOL, Chimera, VMD, O, Olex2 and others. PMID:24904249

Introducing a Public Stereoscopic 3D High Dynamic Range (SHDR) Video Database

NASA Astrophysics Data System (ADS)

Banitalebi-Dehkordi, Amin

2017-03-01

High dynamic range (HDR) displays and cameras are paving their ways through the consumer market at a rapid growth rate. Thanks to TV and camera manufacturers, HDR systems are now becoming available commercially to end users. This is taking place only a few years after the blooming of 3D video technologies. MPEG/ITU are also actively working towards the standardization of these technologies. However, preliminary research efforts in these video technologies are hammered by the lack of sufficient experimental data. In this paper, we introduce a Stereoscopic 3D HDR database of videos that is made publicly available to the research community. We explain the procedure taken to capture, calibrate, and post-process the videos. In addition, we provide insights on potential use-cases, challenges, and research opportunities, implied by the combination of higher dynamic range of the HDR aspect, and depth impression of the 3D aspect.

Initial application of stereoscopic particle image velocimetry to transport and boundary phenomena in dusty plasmas

NASA Astrophysics Data System (ADS)

Thomas, Edward; Williams, Jeremiah; Silver, Jennifer

2004-11-01

Over the past five years, the Auburn Plasma Sciences Laboratory (PSL) has applied two-dimensional particle image velocimetry (2D-PIV) techniques [E. Thomas, Phys. Plasmas, 6, 2672 (1999)] to make measurements of particle transport in dusty plasmas. Although important information was obtained from these earlier studies, the complex behavior of the charged microparticles clearly indicated that three-dimensional velocity information is needed. The PSL has recently acquired and installed a stereoscopic PIV (stereo-PIV) diagnostic tool for dusty plasma investigations [E. Thomas. et al, Phys. Plasmas, L37 (2004)]. It employs a synchronized dual-laser, dual-camera system for measuring particle transport in three dimensions. Results will be presented on the initial application of stereo-PIV to dusty plasma studies. Additional results will be presented on the use of stereo-PIV for measuring the controlled interaction of two dust clouds.

Design of a 3-dimensional visual illusion speed reduction marking scheme.

PubMed

Liang, Guohua; Qian, Guomin; Wang, Ye; Yi, Zige; Ru, Xiaolei; Ye, Wei

2017-03-01

To determine which graphic and color combination for a 3-dimensional visual illusion speed reduction marking scheme presents the best visual stimulus, five parameters were designed. According to the Balanced Incomplete Blocks-Law of Comparative Judgment, three schemes, which produce strong stereoscopic impressions, were screened from the 25 initial design schemes of different combinations of graphics and colors. Three-dimensional experimental simulation scenes of the three screened schemes were created to evaluate four different effects according to a semantic analysis. The following conclusions were drawn: schemes with a red color are more effective than those without; the combination of red, yellow and blue produces the best visual stimulus; a larger area from the top surface and the front surface should be colored red; and a triangular prism should be painted as the graphic of the marking according to the stereoscopic impression and the coordination of graphics with the road.

3D Visualization in Elementary Education Astronomy: Teaching Urban Second Graders about the Sun, Earth, and Moon

NASA Astrophysics Data System (ADS)

Isik-Ercan, Zeynep; Kim, Beomjin; Nowak, Jeffrey

This research-in-progress hypothesizes that urban second graders can have an early understanding about the shape of Sun, Moon, and Earth, how day and night happens, and how Moon appears to change its shape by using three dimensional stereoscopic vision. The 3D stereoscopic vision system might be an effective way to teach subjects like astronomy that explains relationships among objects in space. Currently, Indiana state standards for science teaching do not suggest the teaching of these astronomical concepts explicitly before fourth grade. Yet, we expect our findings to indicate that students can learn these concepts earlier in their educational lives with the implementation of such technologies. We also project that these technologies could revolutionize when these concepts could be taught to children and expand the ways we think about children's cognitive capacities in understanding scientific concepts.

The use of stereoscopic satellite observation in the determination of the emissivity of cirrus

NASA Astrophysics Data System (ADS)

Szejwach, G.; Sletten, T. N.; Hasler, A. F.

The feasibility of determining cirrus ``emissivity'' from combined stereoscopic and infrared satellite observations in conjunction with radiosounding data is investigated for a particular case study. Simultaneous visible images obtained during SESAME-1979 from two geosynchronous GOES meteorological satellites were processed on the NASA/Goddard interactive system (AOIPS) and were used to determine the stereo cloud top height ZC as described by Hasler [1]. Iso-contours of radiances were outlined on the corresponding infrared image. Total brightness temperature TB and ground surface brightness temperature TS were inferred from the radiances. The special SESAME network of radiosoundings was used to determine the cloud top temperature TCLD at the level defined by ZC. The ``effective cirrus emissivity'' NE where N is the fractional cirrus cloudiness and E is the emissivity in a GOES infrared picture element of about 10 km × 10 km is then computed from TB, TS and TCLD.

Gamma rays from dark matter annihilation in three-loop radiative neutrino mass generation models

NASA Astrophysics Data System (ADS)

Chowdhury, Talal Ahmed; Nasri, Salah

2018-07-01

We present the Sommerfeld enhanced Dark Matter (DM) annihilation into gamma ray for a class of three-loop radiative neutrino mass models with large electroweak multiplets where the DM mass is in O(TeV) range. We show that in this model, the DM annihilation rate becomes more prominent for larger multiplets and it is already within the reach of currently operating Imaging Atmospheric Cherenkov telescopes (IACTs), High Energy Stereoscopic System (H.E.S.S.). Furthermore, Cherenkov Telescope Array (CTA), which will begin operating in 2030, will improve this sensitivity by a factor of O (10) and may exclude a large portion of parameter space of this radiative neutrino mass model with larger electroweak multiplet. This implies that the only viable option is the model with lowest electroweak multiplets i.e. singlets of SU(2)L where the DM annihilation rate is not Sommerfeld enhanced and hence it is not yet constrained by the indirect detection limits from H.E.S.S. or future CTA.

Cortical Dynamics of Figure-Ground Separation in Response to 2D Pictures and 3D Scenes: How V2 Combines Border Ownership, Stereoscopic Cues, and Gestalt Grouping Rules

PubMed Central

Grossberg, Stephen

2016-01-01

The FACADE model, and its laminar cortical realization and extension in the 3D LAMINART model, have explained, simulated, and predicted many perceptual and neurobiological data about how the visual cortex carries out 3D vision and figure-ground perception, and how these cortical mechanisms enable 2D pictures to generate 3D percepts of occluding and occluded objects. In particular, these models have proposed how border ownership occurs, but have not yet explicitly explained the correlation between multiple properties of border ownership neurons in cortical area V2 that were reported in a remarkable series of neurophysiological experiments by von der Heydt and his colleagues; namely, border ownership, contrast preference, binocular stereoscopic information, selectivity for side-of-figure, Gestalt rules, and strength of attentional modulation, as well as the time course during which such properties arise. This article shows how, by combining 3D LAMINART properties that were discovered in two parallel streams of research, a unified explanation of these properties emerges. This explanation proposes, moreover, how these properties contribute to the generation of consciously seen 3D surfaces. The first research stream models how processes like 3D boundary grouping and surface filling-in interact in multiple stages within and between the V1 interblob—V2 interstripe—V4 cortical stream and the V1 blob—V2 thin stripe—V4 cortical stream, respectively. Of particular importance for understanding figure-ground separation is how these cortical interactions convert computationally complementary boundary and surface mechanisms into a consistent conscious percept, including the critical use of surface contour feedback signals from surface representations in V2 thin stripes to boundary representations in V2 interstripes. Remarkably, key figure-ground properties emerge from these feedback interactions. The second research stream shows how cells that compute absolute disparity in cortical area V1 are transformed into cells that compute relative disparity in cortical area V2. Relative disparity is a more invariant measure of an object's depth and 3D shape, and is sensitive to figure-ground properties. PMID:26858665

Cortical Dynamics of Figure-Ground Separation in Response to 2D Pictures and 3D Scenes: How V2 Combines Border Ownership, Stereoscopic Cues, and Gestalt Grouping Rules.

PubMed

Grossberg, Stephen

2015-01-01

The FACADE model, and its laminar cortical realization and extension in the 3D LAMINART model, have explained, simulated, and predicted many perceptual and neurobiological data about how the visual cortex carries out 3D vision and figure-ground perception, and how these cortical mechanisms enable 2D pictures to generate 3D percepts of occluding and occluded objects. In particular, these models have proposed how border ownership occurs, but have not yet explicitly explained the correlation between multiple properties of border ownership neurons in cortical area V2 that were reported in a remarkable series of neurophysiological experiments by von der Heydt and his colleagues; namely, border ownership, contrast preference, binocular stereoscopic information, selectivity for side-of-figure, Gestalt rules, and strength of attentional modulation, as well as the time course during which such properties arise. This article shows how, by combining 3D LAMINART properties that were discovered in two parallel streams of research, a unified explanation of these properties emerges. This explanation proposes, moreover, how these properties contribute to the generation of consciously seen 3D surfaces. The first research stream models how processes like 3D boundary grouping and surface filling-in interact in multiple stages within and between the V1 interblob-V2 interstripe-V4 cortical stream and the V1 blob-V2 thin stripe-V4 cortical stream, respectively. Of particular importance for understanding figure-ground separation is how these cortical interactions convert computationally complementary boundary and surface mechanisms into a consistent conscious percept, including the critical use of surface contour feedback signals from surface representations in V2 thin stripes to boundary representations in V2 interstripes. Remarkably, key figure-ground properties emerge from these feedback interactions. The second research stream shows how cells that compute absolute disparity in cortical area V1 are transformed into cells that compute relative disparity in cortical area V2. Relative disparity is a more invariant measure of an object's depth and 3D shape, and is sensitive to figure-ground properties.

Stereo Pair, Salt Lake City, Utah

NASA Technical Reports Server (NTRS)

2002-01-01

The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This image pair provides a stereoscopic map view of north central Utah that includes all of these Olympic sites. In the south, next to Utah Lake, Provo hosts the ice hockey competition. In the north, northeast of the Great Salt Lake, Ogden hosts curling and the nearby Snowbasin ski area hosts the downhill events. In between, southeast of the Great Salt Lake, Salt Lake City hosts the Olympic Village and the various skating events. Further east, across the Wasatch Mountains, the Park City ski resort hosts the bobsled, ski jumping, and snowboarding events. The Winter Olympics are always hosted in mountainous terrain. This view shows the dramatic landscape that makes the Salt Lake City region a world-class center for winter sports.

This stereoscopic image was generated by draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of Earth's surface in its full three dimensions.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter(approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: 222 x 93.8 kilometers (138 x 58.2 miles) Location: 40.0 to 42.0 deg. North lat., 111.25 to 112.25.0 deg. West lon.(exactly) Orientation: North at top Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively. Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 30 meters (98 feet) Date Acquired: February 2000 (SRTM), 1990s (Landsat 5 image mosaic)

SRTM Stereo Pair with Landsat Overlay: Miquelon and Saint Pierre Islands

NASA Technical Reports Server (NTRS)

2000-01-01

This stereoscopic satellite image shows Miquelon and Saint Pierre Islands, located south of Newfoundland, Canada. These islands are a self-governing territory of France. A 'tombolo' (sand bar) unites Grande Miquelon to the north and Petite Miquelon to the south. Saint Pierre Island, located to the lower right, includes a harbor, an airport, and a small town. Glaciers once covered these islands and the direction of glacial flow is evident in the topography as striations and shoreline trends running from the upper right to the lower left. The darkest image features are freshwater lakes that fill glacially carved depressions and saltwater lagoons that are bordered by barrier beaches. The lakes and the lagoons are fairly calm waters and reflect less sunlight than do the wave covered and sediment laden nearshore ocean currents.

This stereoscopic image was generated by draping a Landsat satellite image over a preliminary Shuttle Radar Topography Mission (SRTM)elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) DataCenter, Sioux Falls, South Dakota.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60-meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington DC.

Size: 48 by 38 kilometers (30 by 24 miles) Location: 47 deg. North lat., 56.3 deg. West lon. Orientation: North toward the upper left Image Data: Landsat bands 1, 2+4, 3 in blue, green, red, respectively Date Acquired: February 12, 2000 (SRTM), September 1, 1999 (Landsat) Image: NASA/JPL/NIMA

SRTM Stereo Pair: Bhuj, India, Two Weeks After earthquake

NASA Technical Reports Server (NTRS)

2001-01-01

On January 26, 2001, the city of Bhuj suffered the most deadly earthquake in India's history. About 20,000 people were killed, and more than one million homes were damaged or destroyed. Shortly after the quake, geologists conducted field investigations to inventory and analyze the natural effects of the event. Stereoscopic views, similar to this image, aided the geologists in locating landforms indicative of long-term (and possibly ongoing) deformation. Soon, elevation data from the Shuttle Radar Topography Mission (SRTM) will be used in the study of a wide variety of natural hazards worldwide.

In this image, the city of Bhuj appears as a gray area at the scene center, and the city airport is toward the north (top). Vegetation appears green. Rugged but low relief hills of previously folded and faulted bedrock appear south (bottom) and northwest (upper-left) of the city.

This stereoscopic image was generated by draping a Landsat satellite image (taken just two weeks after the earthquake) over a preliminary SRTM elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing) or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar(SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: 13.5 x 20.6 kilometers ( 8.4 x 12.8 miles) Location: 23.3 deg. North lat., 69.7 deg. East lon. Orientation: North toward the top Image Data: Landsat Bands 1, 2+4, 3 as blue, green, red, respectively Date Acquired: February 2000 (SRTM), February 9, 2001 (Landsat)

A study to evaluate the reliability of using two-dimensional photographs, three-dimensional images, and stereoscopic projected three-dimensional images for patient assessment.

PubMed

Zhu, S; Yang, Y; Khambay, B

2017-03-01

Clinicians are accustomed to viewing conventional two-dimensional (2D) photographs and assume that viewing three-dimensional (3D) images is similar. Facial images captured in 3D are not viewed in true 3D; this may alter clinical judgement. The aim of this study was to evaluate the reliability of using conventional photographs, 3D images, and stereoscopic projected 3D images to rate the severity of the deformity in pre-surgical class III patients. Forty adult patients were recruited. Eight raters assessed facial height, symmetry, and profile using the three different viewing media and a 100-mm visual analogue scale (VAS), and appraised the most informative viewing medium. Inter-rater consistency was above good for all three media. Intra-rater reliability was not significantly different for rating facial height using 2D (P=0.704), symmetry using 3D (P=0.056), and profile using projected 3D (P=0.749). Using projected 3D for rating profile and symmetry resulted in significantly lower median VAS scores than either 3D or 2D images (all P<0.05). For 75% of the raters, stereoscopic 3D projection was the preferred method for rating. The reliability of assessing specific characteristics was dependent on the viewing medium. Clinicians should be aware that the visual information provided when viewing 3D images is not the same as when viewing 2D photographs, especially for facial depth, and this may change the clinical impression. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Wide-Field-of-View, High-Resolution, Stereoscopic Imager

NASA Technical Reports Server (NTRS)

Prechtl, Eric F.; Sedwick, Raymond J.

2010-01-01

A device combines video feeds from multiple cameras to provide wide-field-of-view, high-resolution, stereoscopic video to the user. The prototype under development consists of two camera assemblies, one for each eye. One of these assemblies incorporates a mounting structure with multiple cameras attached at offset angles. The video signals from the cameras are fed to a central processing platform where each frame is color processed and mapped into a single contiguous wide-field-of-view image. Because the resolution of most display devices is typically smaller than the processed map, a cropped portion of the video feed is output to the display device. The positioning of the cropped window will likely be controlled through the use of a head tracking device, allowing the user to turn his or her head side-to-side or up and down to view different portions of the captured image. There are multiple options for the display of the stereoscopic image. The use of head mounted displays is one likely implementation. However, the use of 3D projection technologies is another potential technology under consideration, The technology can be adapted in a multitude of ways. The computing platform is scalable, such that the number, resolution, and sensitivity of the cameras can be leveraged to improve image resolution and field of view. Miniaturization efforts can be pursued to shrink the package down for better mobility. Power savings studies can be performed to enable unattended, remote sensing packages. Image compression and transmission technologies can be incorporated to enable an improved telepresence experience.

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

Sattarivand, Mike; Summers, Clare; Robar, James

Purpose: To evaluate the validity of using spine as a surrogate for tumor positioning with ExacTrac stereoscopic imaging in lung stereotactic body radiation therapy (SBRT). Methods: Using the Novalis ExacTrac x-ray system, 39 lung SBRT patients (182 treatments) were aligned before treatment with 6 degrees (6D) of freedom couch (3 translations, 3 rotations) based on spine matching on stereoscopic images. The couch was shifted to treatment isocenter and pre-treatment CBCT was performed based on a soft tissue match around tumor volume. The CBCT data were used to measure residual errors following ExacTrac alignment. The thresholds for re-aligning the patients basedmore » on CBCT were 3mm shift or 3° rotation (in any 6D). In order to evaluate the effect of tumor location on residual errors, correlations between tumor distance from spine and individual residual errors were calculated. Results: Residual errors were up to 0.5±2.4mm. Using 3mm/3° thresholds, 80/182 (44%) of the treatments required re-alignment based on CBCT soft tissue matching following ExacTrac spine alignment. Most mismatches were in sup-inf, ant-post, and roll directions which had larger standard deviations. No correlation was found between tumor distance from spine and individual residual errors. Conclusion: ExacTrac stereoscopic imaging offers a quick pre-treatment patient alignment. However, bone matching based on spine is not reliable for aligning lung SBRT patients who require soft tissue image registration from CBCT. Spine can be a poor surrogate for lung SBRT patient alignment even for proximal tumor volumes.« less

Assessing the precision of gaze following using a stereoscopic 3D virtual reality setting.

PubMed

Atabaki, Artin; Marciniak, Karolina; Dicke, Peter W; Thier, Peter

2015-07-01

Despite the ecological importance of gaze following, little is known about the underlying neuronal processes, which allow us to extract gaze direction from the geometric features of the eye and head of a conspecific. In order to understand the neuronal mechanisms underlying this ability, a careful description of the capacity and the limitations of gaze following at the behavioral level is needed. Previous studies of gaze following, which relied on naturalistic settings have the disadvantage of allowing only very limited control of potentially relevant visual features guiding gaze following, such as the contrast of iris and sclera, the shape of the eyelids and--in the case of photographs--they lack depth. Hence, in order to get full control of potentially relevant features we decided to study gaze following of human observers guided by the gaze of a human avatar seen stereoscopically. To this end we established a stereoscopic 3D virtual reality setup, in which we tested human subjects' abilities to detect at which target a human avatar was looking at. Following the gaze of the avatar showed all the features of the gaze following of a natural person, namely a substantial degree of precision associated with a consistent pattern of systematic deviations from the target. Poor stereo vision affected performance surprisingly little (only in certain experimental conditions). Only gaze following guided by targets at larger downward eccentricities exhibited a differential effect of the presence or absence of accompanying movements of the avatar's eyelids and eyebrows. Copyright © 2015 Elsevier Ltd. All rights reserved.

Full-color stereoscopic single-pixel camera based on DMD technology

NASA Astrophysics Data System (ADS)

Salvador-Balaguer, Eva; Clemente, Pere; Tajahuerce, Enrique; Pla, Filiberto; Lancis, Jesús

2017-02-01

Imaging systems based on microstructured illumination and single-pixel detection offer several advantages over conventional imaging techniques. They are an effective method for imaging through scattering media even in the dynamic case. They work efficiently under low light levels, and the simplicity of the detector makes it easy to design imaging systems working out of the visible spectrum and to acquire multidimensional information. In particular, several approaches have been proposed to record 3D information. The technique is based on sampling the object with a sequence of microstructured light patterns codified onto a programmable spatial light modulator while light intensity is measured with a single-pixel detector. The image is retrieved computationally from the photocurrent fluctuations provided by the detector. In this contribution we describe an optical system able to produce full-color stereoscopic images by using few and simple optoelectronic components. In our setup we use an off-the-shelf digital light projector (DLP) based on a digital micromirror device (DMD) to generate the light patterns. To capture the color of the scene we take advantage of the codification procedure used by the DLP for color video projection. To record stereoscopic views we use a 90° beam splitter and two mirrors, allowing us two project the patterns form two different viewpoints. By using a single monochromatic photodiode we obtain a pair of color images that can be used as input in a 3-D display. To reduce the time we need to project the patterns we use a compressive sampling algorithm. Experimental results are shown.

The design and implementation of stereoscopic 3D scalable vector graphics based on WebKit

NASA Astrophysics Data System (ADS)

Liu, Zhongxin; Wang, Wenmin; Wang, Ronggang

2014-03-01

Scalable Vector Graphics (SVG), which is a language designed based on eXtensible Markup Language (XML), is used to describe basic shapes embedded in webpages, such as circles and rectangles. However, it can only depict 2D shapes. As a consequence, web pages using classical SVG can only display 2D shapes on a screen. With the increasing development of stereoscopic 3D (S3D) technology, binocular 3D devices have been widely used. Under this circumstance, we intend to extend the widely used web rendering engine WebKit to support the description and display of S3D webpages. Therefore, the extension of SVG is of necessity. In this paper, we will describe how to design and implement SVG shapes with stereoscopic 3D mode. Two attributes representing the depth and thickness are added to support S3D shapes. The elimination of hidden lines and hidden surfaces, which is an important process in this project, is described as well. The modification of WebKit is also discussed, which is made to support the generation of both left view and right view at the same time. As is shown in the result, in contrast to the 2D shapes generated by the Google Chrome web browser, the shapes got from our modified browser are in S3D mode. With the feeling of depth and thickness, the shapes seem to be real 3D objects away from the screen, rather than simple curves and lines as before.

Stereoscopic 3D reconstruction using motorized zoom lenses within an embedded system

NASA Astrophysics Data System (ADS)

Liu, Pengcheng; Willis, Andrew; Sui, Yunfeng

2009-02-01

This paper describes a novel embedded system capable of estimating 3D positions of surfaces viewed by a stereoscopic rig consisting of a pair of calibrated cameras. Novel theoretical and technical aspects of the system are tied to two aspects of the design that deviate from typical stereoscopic reconstruction systems: (1) incorporation of an 10x zoom lens (Rainbow- H10x8.5) and (2) implementation of the system on an embedded system. The system components include a DSP running μClinux, an embedded version of the Linux operating system, and an FPGA. The DSP orchestrates data flow within the system and performs complex computational tasks and the FPGA provides an interface to the system devices which consist of a CMOS camera pair and a pair of servo motors which rotate (pan) each camera. Calibration of the camera pair is accomplished using a collection of stereo images that view a common chess board calibration pattern for a set of pre-defined zoom positions. Calibration settings for an arbitrary zoom setting are estimated by interpolation of the camera parameters. A low-computational cost method for dense stereo matching is used to compute depth disparities for the stereo image pairs. Surface reconstruction is accomplished by classical triangulation of the matched points from the depth disparities. This article includes our methods and results for the following problems: (1) automatic computation of the focus and exposure settings for the lens and camera sensor, (2) calibration of the system for various zoom settings and (3) stereo reconstruction results for several free form objects.

Spirit Lookout Panorama in 3-D

NASA Image and Video Library

2005-05-23

This is a stereoscopic version of NASA Mars Exploration Rover Spirit Lookout panorama, acquired on Feb. 27 to Mar. 2, 2005. The view is from a position known informally as Larry Lookout. 3D glasses are necessary to view this image.

Southern Haiti Anaglyph

NASA Image and Video Library

2010-01-14

This image, produced from instrument data aboard NASA Space Shuttle Endeavour, is a stereoscopic view of the topography of Port-au-Prince, Haiti where a magnitude 7.0 earthquake occurred on January 12, 2010. You need 3-D glasses to view this image.

Stereo Pair of Height as Color & Shaded Relief, New York State, Lake Ontario to Long Island

NASA Technical Reports Server (NTRS)

2000-01-01

From Lake Ontario and the St. Lawrence River (at the top of the image) and extending to Long Island (at the bottom) this image shows the varied topography of eastern New York State and parts of Massachusetts, Connecticut, Pennsylvania and New Jersey. The high 'bumpy' area in the middle to top right is the southern and western Adirondack Mountains, a deeply eroded landscape that includes the oldest exposed rocks in the eastern U.S.

On the left side is the Catskill Mountains, a part of the Appalachian Mountain chain, where river erosion has produced an intricate pattern of valleys. Between the Adirondacks and Catskills is a wide valley that contains the Mohawk River and the Erie Canal. On the northwest (top) of the Catskills are several long, narrow lakes, some of the Finger Lakes of central New York that were carved by the vast glacier that covered this entire image as recently as 18,000 years ago.

The Hudson River runs along a straight valley from right center (near Glens Falls), widening out as it approaches New York City at the lower left on the image. The Connecticut River valley has a similar north-south trend further to the east (across the lower right corner of the image). The Berkshires are between the Hudson and Connecticut valleys. Closer to the coast are the more deeply eroded rocks of the area around New York City, where several resistant rock units form topographic ridges.

This image product is derived from a preliminary SRTM elevation model, processed with preliminary navigation information from the Space Shuttle. Broad scale and fine detail distortions in the model seen here will be corrected in the final elevation model.

This stereoscopic image was generated by first creating and combining a shaded relief image and a height as color image, both of which were derived from the elevation model. Large water bodies were then masked, and the result was then draped back over the elevation model. Two differing perspectives were then calculated, one for each eye. This color image can be viewed in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair, and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

This image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington DC.

Size: 220 by 510 kilometers (135 by 315 miles) Location: 43 deg. North lat., 75 deg. West lon. Orientation: North toward the upper right Date Acquired: February 13, 2000

An interactive, stereoscopic virtual environment for medical imaging visualization, simulation and training

NASA Astrophysics Data System (ADS)

Krueger, Evan; Messier, Erik; Linte, Cristian A.; Diaz, Gabriel

2017-03-01

Recent advances in medical image acquisition allow for the reconstruction of anatomies with 3D, 4D, and 5D renderings. Nevertheless, standard anatomical and medical data visualization still relies heavily on the use of traditional 2D didactic tools (i.e., textbooks and slides), which restrict the presentation of image data to a 2D slice format. While these approaches have their merits beyond being cost effective and easy to disseminate, anatomy is inherently three-dimensional. By using 2D visualizations to illustrate more complex morphologies, important interactions between structures can be missed. In practice, such as in the planning and execution of surgical interventions, professionals require intricate knowledge of anatomical complexities, which can be more clearly communicated and understood through intuitive interaction with 3D volumetric datasets, such as those extracted from high-resolution CT or MRI scans. Open source, high quality, 3D medical imaging datasets are freely available, and with the emerging popularity of 3D display technologies, affordable and consistent 3D anatomical visualizations can be created. In this study we describe the design, implementation, and evaluation of one such interactive, stereoscopic visualization paradigm for human anatomy extracted from 3D medical images. A stereoscopic display was created by projecting the scene onto the lab floor using sequential frame stereo projection and viewed through active shutter glasses. By incorporating a PhaseSpace motion tracking system, a single viewer can navigate an augmented reality environment and directly manipulate virtual objects in 3D. While this paradigm is sufficiently versatile to enable a wide variety of applications in need of 3D visualization, we designed our study to work as an interactive game, which allows users to explore the anatomy of various organs and systems. In this study we describe the design, implementation, and evaluation of an interactive and stereoscopic visualization platform for exploring and understanding human anatomy. This system can present medical imaging data in three dimensions and allows for direct physical interaction and manipulation by the viewer. This should provide numerous benefits over traditional, 2D display and interaction modalities, and in our analysis, we aim to quantify and qualify users' visual and motor interactions with the virtual environment when employing this interactive display as a 3D didactic tool.

Mobile robots IV; Proceedings of the Meeting, Philadelphia, PA, Nov. 6, 7, 1989

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

Wolfe, W.J.; Chun, W.H.

1990-01-01

The present conference on mobile robot systems discusses high-speed machine perception based on passive sensing, wide-angle optical ranging, three-dimensional path planning for flying/crawling robots, navigation of autonomous mobile intelligence in an unstructured natural environment, mechanical models for the locomotion of a four-articulated-track robot, a rule-based command language for a semiautonomous Mars rover, and a computer model of the structured light vision system for a Mars rover. Also discussed are optical flow and three-dimensional information for navigation, feature-based reasoning trail detection, a symbolic neural-net production system for obstacle avoidance and navigation, intelligent path planning for robot navigation in an unknown environment,more » behaviors from a hierarchical control system, stereoscopic TV systems, the REACT language for autonomous robots, and a man-amplifying exoskeleton.« less

Morphology and three-dimensional reconstruction of the digestive system of Periplaneta americana.

PubMed

Ma, Hui; Liu, Zhi-Gang; Bao, Ying; Ran, Pi-Xin; Zhong, Nan-Shan

2009-01-01

A three-dimensional (3-D) model of the digestive system of Periplaneta americana was built for the first time based on hematoxylin and eosin (H&E) staining, the study of multiple cross-sections of the larval cockroach, and 3-D reconstruction technology. The digestive system of P. americana includes the foregut, midgut, and hindgut and takes up most of the celom. The foregut comprises almost one half of the digestive system (43.57%). The midgut, the critical region for digestion and absorption, has the second highest volume ratio (35.21%). The hindgut, with the lowest volume ratio (21.22%), includes the ileum, colon, and rectum. After the ileal valve is the colon. The 3-D model presented in this paper provides a stereoscopic view for studying the adjacent relationship and arrangement of different gut sections of P. americana.

Rolling friction and energy dissipation in a spinning disc

PubMed Central

Ma, Daolin; Liu, Caishan; Zhao, Zhen; Zhang, Hongjian

2014-01-01

This paper presents the results of both experimental and theoretical investigations for the dynamics of a steel disc spinning on a horizontal rough surface. With a pair of high-speed cameras, a stereoscopic vision method is adopted to perform omnidirectional measurements for the temporal evolution of the disc's motion. The experiment data allow us to detail the dynamics of the disc, and consequently to quantify its energy. From our experimental observations, it is confirmed that rolling friction is a primary factor responsible for the dissipation of the energy. Furthermore, a mathematical model, in which the rolling friction is characterized by a resistance torque proportional to the square of precession rate, is also proposed. By employing the model, we perform qualitative analysis and numerical simulations. Both of them provide results that precisely agree with our experimental findings. PMID:25197246

Visual Attention and Applications in Multimedia Technologies

PubMed Central

Le Callet, Patrick; Niebur, Ernst

2013-01-01

Making technological advances in the field of human-machine interactions requires that the capabilities and limitations of the human perceptual system are taken into account. The focus of this report is an important mechanism of perception, visual selective attention, which is becoming more and more important for multimedia applications. We introduce the concept of visual attention and describe its underlying mechanisms. In particular, we introduce the concepts of overt and covert visual attention, and of bottom-up and top-down processing. Challenges related to modeling visual attention and their validation using ad hoc ground truth are also discussed. Examples of the usage of visual attention models in image and video processing are presented. We emphasize multimedia delivery, retargeting and quality assessment of image and video, medical imaging, and the field of stereoscopic 3D images applications. PMID:24489403

Japan Smoke

Atmospheric Science Data Center

2013-04-16

... is a stereoscopic "anaglyph" created from data in MISR's red spectral band, and generated by displaying the 46-degree backward view in red ... the surface. Viewing the anaglyph with red-cyan glasses (red filter over the left eye) gives a perception of height. No separation is ...

13. EQUIPMENT USED IN CLEAN ROOM (102), INCLUDING ROYCO PARTICLE ...

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

13. EQUIPMENT USED IN CLEAN ROOM (102), INCLUDING ROYCO PARTICLE COUNTER (LEFT) AND STEREOSCOPE FOR MANUAL PARTICLE COUNTING (RIGHT) - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Bluff-body drag reduction using a deflector

NASA Astrophysics Data System (ADS)

Fourrié, Grégoire; Keirsbulck, Laurent; Labraga, Larbi; Gilliéron, Patrick

2011-02-01

A passive flow control on a generic car model was experimentally studied. This control consists of a deflector placed on the upper edge of the model rear window. The study was carried out in a wind tunnel at Reynolds numbers based on the model height of 3.1 × 105 and 7.7 × 105. The flow was investigated via standard and stereoscopic particle image velocimetry, Kiel pressure probes and surface flow visualization. The aerodynamic drag was measured using an external balance and calculated using a wake survey method. Drag reductions up to 9% were obtained depending on the deflector angle. The deflector increases the separated region on the rear window. The results show that when this separated region is wide enough, it disrupts the development of the counter-rotating longitudinal vortices appearing on the lateral edges of the rear window. The current study suggests that flow control on such geometries should consider all the flow structures that contribute to the model wake flow.

Three Software Tools for Viewing Sectional Planes, Volume Models, and Surface Models of a Cadaver Hand.

PubMed

Chung, Beom Sun; Chung, Min Suk; Shin, Byeong Seok; Kwon, Koojoo

2018-02-19

The hand anatomy, including the complicated hand muscles, can be grasped by using computer-assisted learning tools with high quality two-dimensional images and three-dimensional models. The purpose of this study was to present up-to-date software tools that promote learning of stereoscopic morphology of the hand. On the basis of horizontal sectioned images and outlined images of a male cadaver, vertical planes, volume models, and surface models were elaborated. Software to browse pairs of the sectioned and outlined images in orthogonal planes and software to peel and rotate the volume models, as well as a portable document format (PDF) file to select and rotate the surface models, were produced. All of the software tools were downloadable free of charge and usable off-line. The three types of tools for viewing multiple aspects of the hand could be adequately employed according to individual needs. These new tools involving the realistic images of a cadaver and the diverse functions are expected to improve comprehensive knowledge of the hand shape. © 2018 The Korean Academy of Medical Sciences.

Three Software Tools for Viewing Sectional Planes, Volume Models, and Surface Models of a Cadaver Hand

PubMed Central

2018-01-01

Background The hand anatomy, including the complicated hand muscles, can be grasped by using computer-assisted learning tools with high quality two-dimensional images and three-dimensional models. The purpose of this study was to present up-to-date software tools that promote learning of stereoscopic morphology of the hand. Methods On the basis of horizontal sectioned images and outlined images of a male cadaver, vertical planes, volume models, and surface models were elaborated. Software to browse pairs of the sectioned and outlined images in orthogonal planes and software to peel and rotate the volume models, as well as a portable document format (PDF) file to select and rotate the surface models, were produced. Results All of the software tools were downloadable free of charge and usable off-line. The three types of tools for viewing multiple aspects of the hand could be adequately employed according to individual needs. Conclusion These new tools involving the realistic images of a cadaver and the diverse functions are expected to improve comprehensive knowledge of the hand shape. PMID:29441756

Robust cue integration: a Bayesian model and evidence from cue-conflict studies with stereoscopic and figure cues to slant.

PubMed

Knill, David C

2007-05-23

Most research on depth cue integration has focused on stimulus regimes in which stimuli contain the small cue conflicts that one might expect to normally arise from sensory noise. In these regimes, linear models for cue integration provide a good approximation to system performance. This article focuses on situations in which large cue conflicts can naturally occur in stimuli. We describe a Bayesian model for nonlinear cue integration that makes rational inferences about scenes across the entire range of possible cue conflicts. The model derives from the simple intuition that multiple properties of scenes or causal factors give rise to the image information associated with most cues. To make perceptual inferences about one property of a scene, an ideal observer must necessarily take into account the possible contribution of these other factors to the information provided by a cue. In the context of classical depth cues, large cue conflicts most commonly arise when one or another cue is generated by an object or scene that violates the strongest form of constraint that makes the cue informative. For example, when binocularly viewing a slanted trapezoid, the slant interpretation of the figure derived by assuming that the figure is rectangular may conflict greatly with the slant suggested by stereoscopic disparities. An optimal Bayesian estimator incorporates the possibility that different constraints might apply to objects in the world and robustly integrates cues with large conflicts by effectively switching between different internal models of the prior constraints underlying one or both cues. We performed two experiments to test the predictions of the model when applied to estimating surface slant from binocular disparities and the compression cue (the aspect ratio of figures in an image). The apparent weight that subjects gave to the compression cue decreased smoothly as a function of the conflict between the cues but did not shrink to zero; that is, subjects did not fully veto the compression cue at large cue conflicts. A Bayesian model that assumes a mixed prior distribution of figure shapes in the world, with a large proportion being very regular and a smaller proportion having random shapes, provides a good quantitative fit for subjects' performance. The best fitting model parameters are consistent with the sensory noise to be expected in measurements of figure shape, further supporting the Bayesian model as an account of robust cue integration.

An investigation of visual selection priority of objects with texture and crossed and uncrossed disparities

NASA Astrophysics Data System (ADS)

Khaustova, Dar'ya; Fournier, Jérôme; Wyckens, Emmanuel; Le Meur, Olivier

2014-02-01

The aim of this research is to understand the difference in visual attention to 2D and 3D content depending on texture and amount of depth. Two experiments were conducted using an eye-tracker and a 3DTV display. Collected fixation data were used to build saliency maps and to analyze the differences between 2D and 3D conditions. In the first experiment 51 observers participated in the test. Using scenes that contained objects with crossed disparity, it was discovered that such objects are the most salient, even if observers experience discomfort due to the high level of disparity. The goal of the second experiment is to decide whether depth is a determinative factor for visual attention. During the experiment, 28 observers watched the scenes that contained objects with crossed and uncrossed disparities. We evaluated features influencing the saliency of the objects in stereoscopic conditions by using contents with low-level visual features. With univariate tests of significance (MANOVA), it was detected that texture is more important than depth for selection of objects. Objects with crossed disparity are significantly more important for selection processes when compared to 2D. However, objects with uncrossed disparity have the same influence on visual attention as 2D objects. Analysis of eyemovements indicated that there is no difference in saccade length. Fixation durations were significantly higher in stereoscopic conditions for low-level stimuli than in 2D. We believe that these experiments can help to refine existing models of visual attention for 3D content.

Perception of scene-relative object movement: Optic flow parsing and the contribution of monocular depth cues.

PubMed

Warren, Paul A; Rushton, Simon K

2009-05-01

We have recently suggested that the brain uses its sensitivity to optic flow in order to parse retinal motion into components arising due to self and object movement (e.g. Rushton, S. K., & Warren, P. A. (2005). Moving observers, 3D relative motion and the detection of object movement. Current Biology, 15, R542-R543). Here, we explore whether stereo disparity is necessary for flow parsing or whether other sources of depth information, which could theoretically constrain flow-field interpretation, are sufficient. Stationary observers viewed large field of view stimuli containing textured cubes, moving in a manner that was consistent with a complex observer movement through a stationary scene. Observers made speeded responses to report the perceived direction of movement of a probe object presented at different depths in the scene. Across conditions we varied the presence or absence of different binocular and monocular cues to depth order. In line with previous studies, results consistent with flow parsing (in terms of both perceived direction and response time) were found in the condition in which motion parallax and stereoscopic disparity were present. Observers were poorer at judging object movement when depth order was specified by parallax alone. However, as more monocular depth cues were added to the stimulus the results approached those found when the scene contained stereoscopic cues. We conclude that both monocular and binocular static depth information contribute to flow parsing. These findings are discussed in the context of potential architectures for a model of the flow parsing mechanism.

Augmented microscopy with near-infrared fluorescence detection

NASA Astrophysics Data System (ADS)

Watson, Jeffrey R.; Martirosyan, Nikolay; Skoch, Jesse; Lemole, G. Michael; Anton, Rein; Romanowski, Marek

2015-03-01

Near-infrared (NIR) fluorescence has become a frequently used intraoperative technique for image-guided surgical interventions. In procedures such as cerebral angiography, surgeons use the optical surgical microscope for the color view of the surgical field, and then switch to an electronic display for the NIR fluorescence images. However, the lack of stereoscopic, real-time, and on-site coregistration adds time and uncertainty to image-guided surgical procedures. To address these limitations, we developed the augmented microscope, whereby the electronically processed NIR fluorescence image is overlaid with the anatomical optical image in real-time within the optical path of the microscope. In vitro, the augmented microscope can detect and display indocyanine green (ICG) concentrations down to 94.5 nM, overlaid with the anatomical color image. We prepared polyacrylamide tissue phantoms with embedded polystyrene beads, yielding scattering properties similar to brain matter. In this model, 194 μM solution of ICG was detectable up to depths of 5 mm. ICG angiography was then performed in anesthetized rats. A dynamic process of ICG distribution in the vascular system overlaid with anatomical color images was observed and recorded. In summary, the augmented microscope demonstrates NIR fluorescence detection with superior real-time coregistration displayed within the ocular of the stereomicroscope. In comparison to other techniques, the augmented microscope retains full stereoscopic vision and optical controls including magnification and focus, camera capture, and multiuser access. Augmented microscopy may find application in surgeries where the use of traditional microscopes can be enhanced by contrast agents and image guided delivery of therapeutics, including oncology, neurosurgery, and ophthalmology.

Visual perception and stereoscopic imaging: an artist's perspective

NASA Astrophysics Data System (ADS)

Mason, Steve

2015-03-01

This paper continues my 2014 February IS and T/SPIE Convention exploration into the relationship of stereoscopic vision and consciousness (90141F-1). It was proposed then that by using stereoscopic imaging people may consciously experience, or see, what they are viewing and thereby help make them more aware of the way their brains manage and interpret visual information. Environmental imaging was suggested as a way to accomplish this. This paper is the result of further investigation, research, and follow-up imaging. A show of images, that is a result of this research, allows viewers to experience for themselves the effects of stereoscopy on consciousness. Creating dye-infused aluminum prints while employing ChromaDepth® 3D glasses, I hope to not only raise awareness of visual processing but also explore the differences and similarities between the artist and scientist―art increases right brain spatial consciousness, not only empirical thinking, while furthering the viewer's cognizance of the process of seeing. The artist must abandon preconceptions and expectations, despite what the evidence and experience may indicate in order to see what is happening in his work and to allow it to develop in ways he/she could never anticipate. This process is then revealed to the viewer in a show of work. It is in the experiencing, not just from the thinking, where insight is achieved. Directing the viewer's awareness during the experience using stereoscopic imaging allows for further understanding of the brain's function in the visual process. A cognitive transformation occurs, the preverbal "left/right brain shift," in order for viewers to "see" the space. Using what we know from recent brain research, these images will draw from certain parts of the brain when viewed in two dimensions and different ones when viewed stereoscopically, a shift, if one is looking for it, which is quite noticeable. People who have experienced these images in the context of examining their own visual process have been startled by the effect they have on how they perceive the world around them. For instance, when viewing the mountains on a trip to Montana, one woman exclaimed, "I could no longer see just mountains, but also so many amazing colors and shapes"―she could see beyond her preconceptions of mountains to realize more of the beauty that was really there, not just the objects she "thought" to be there. The awareness gained from experiencing the artist's perspective will help with creative thinking in particular and overall research in general. Perceiving the space in these works, completely removing the picture-plane by use of the 3D glasses, making a conscious connection between the feeling and visual content, and thus gaining a deeper appreciation of the visual process will all contribute to understanding how our thinking, our left-brain domination, gets in the way of our seeing what is right in front of us. We fool ourselves with concept and memory―experiencing these prints may help some come a little closer to reality.

Using Stereoscopy to Teach Complex Biological Concepts

ERIC Educational Resources Information Center

Ferdig, Richard; Blank, James; Kratcoski, Annette; Clements, Robert

2015-01-01

Used effectively, stereoscopic three-dimensional (3D) technologies can engage students with complex disciplinary content as they are presented with informative representations of abstract concepts. In addition, preliminary evidence suggests that stereoscopy may enhance learning and retention in some educational settings. Biological concepts…

Stereochronoscopy of the optic disc with stereoscopic cameras.

PubMed

Schirmer, K E; Kratky, V

1980-09-01

Goldmann's chronoscopy, a form of time-based photogrammetry of the optic disc, can be accomplished by repeated simultaneous stereophotography. The variations in centration and image orientation are nulled by azimuthal rotation and fusion of two pairs of stereophotographs taken at separate times.

Computer Graphics Instruction in VizClass

ERIC Educational Resources Information Center

Grimes, Douglas; Warschauer, Mark; Hutchinson, Tara; Kuester, Falko

2005-01-01

"VizClass" is a university classroom environment designed to offer students in computer graphics and engineering courses up-to-date visualization technologies. Three digital whiteboards and a three-dimensional stereoscopic display provide complementary display surfaces. Input devices include touchscreens on the digital whiteboards, remote…

Colby Fire over LA Basin

Atmospheric Science Data Center

2014-05-15

... full resolution figures image   On Jan. 16, 2014, dry conditions and warm winter temperatures in California permitted embers from ... when viewed with red/blue glasses (red filter over the left eye). To give the stereoscopic effect, this image is rotated so that North is ...

Strabismus and Amblyopia.

ERIC Educational Resources Information Center

Trief, E.; Morse, A. R.

1988-01-01

Strabismus and amblyopia are two common childhood vision conditions requiring early identification and treatment. Screening devices include external examination of the eye, ability to track, a cover test, acuity tests, and stereoscopic tests. Treatment includes patching therapy, use of glasses, orthoptics, CAM vision stimulator, or a combination…

Supersonic Combustion Ramjet Research

DTIC Science & Technology

2012-08-01

was in collaboration with Prof. R. Bowersox (Texas A&M University) and Dr. K. Kobayashi ( Japanese Aerospace Exploration Agency, JAXA). 4.2 Ignition... cinema stereoscopic PIV system for the measurement of micro- and meso-scale turbulent premixed flame dynamics,” Paper B13, 5th US Combustion

[Rehabilitation by hollow obturator prosthesis immediately after total maxillectomy for malignant tumor].

PubMed

Li, Xiao-ye; Yan, Ai-hui; Hao, Shuai; Li, Wei; Jiang, Xue-jun; Lu, Li; Qin, Xing-jun; Yan, Hai-xin

2011-05-01

The feasibility and clinical effects of hollow obturator prosthesis for the repair of maxillofacial defect immediately after maxillectomy for cancer were assessed. Thirteen patients with T3-4aN0M0 maxillary neoplasm were treated by the prostheses immediately after maxillectomy. According to the 3D-CT reconstruction of nasal sinus, the 3D stereoscopic prototype was constructed before the surgery. Simulating surgery with Surgicare 5.0 software and then the prosthesis 3D stereoscopic model was shaped. The prosthesis was made quickly and precisely with methacrylate resins according to the model and the print mold before surgery, with supplementary tooth at the bottom of prosthesis. In the surgery, the prosthesis was installed instantly after maxillectomy. The patients were followed up at 1, 3 and 6 month after the surgery, respectively. The facial features and the pronunciation clarity were examined and the questionnaires were carried out in the patients, with comparation by paired t-test. The hollow obturator prosthesis would be replaced by permanent prosthesis made of methacrylate resins at 6 month after the surgery. The hollow obturator prostheses were installed accurately and maxillofacial defects were repaired immediately after maxillectomy in the 13 patients. Postoperative follow-up showed there were significant differences in eyeball sagging (t = 4.67, P < 0.05), mid-facial region collapse (t = 5.67, P < 0.05), and pronunciation clarity (t = 16.38, P < 0.05) between patients with and without prostheses. Questionnaires showed that all the patients were satisfied with the retention of prostheses, the improvement of appearance, the improvement of the symptom of water choking and speech definition. Six months after the surgery, the hollow obturator prostheses were replaced smoothly by permanent prostheses in 11 of the 13 patients. The precise and instant repair of maxillofacial defect by prosthesis after maxillectomy can improve survival quality of patient.

Interplanetary density models as inferred from solar Type III bursts

NASA Astrophysics Data System (ADS)

Oppeneiger, Lucas; Boudjada, Mohammed Y.; Lammer, Helmut; Lichtenegger, Herbert

2016-04-01

We report on the density models derived from spectral features of solar Type III bursts. They are generated by beams of electrons travelling outward from the Sun along open magnetic field lines. Electrons generate Langmuir waves at the plasma frequency along their ray paths through the corona and the interplanetary medium. A large frequency band is covered by the Type III bursts from several MHz down to few kHz. In this analysis, we consider the previous empirical density models proposed to describe the electron density in the interplanetary medium. We show that those models are mainly based on the analysis of Type III bursts generated in the interplanetary medium and observed by satellites (e.g. RAE, HELIOS, VOYAGER, ULYSSES,WIND). Those models are confronted to stereoscopic observations of Type III bursts recorded by WIND, ULYSSES and CASSINI spacecraft. We discuss the spatial evolution of the electron beam along the interplanetary medium where the trajectory is an Archimedean spiral. We show that the electron beams and the source locations are depending on the choose of the empirical density models.

3D Printing of Biomolecular Models for Research and Pedagogy

PubMed Central

Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel

2017-01-01

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology. PMID:28362403

Differences in Optical Coherence Tomography Assessment of Bruch Membrane Opening Compared to Stereoscopic Photography for Estimating Cup-to-Disc Ratio.

PubMed

Mwanza, Jean-Claude; Huang, Linda Y; Budenz, Donald L; Shi, Wei; Huang, Gintien; Lee, Richard K

2017-12-01

To compare the vertical and horizontal cup-to-disc ratio (VCDR, HCDR) by an updated optical coherence tomography (OCT) Bruch membrane opening (BMO) algorithm and stereoscopic optic disc photograph readings by glaucoma specialists. Reliability analysis. A total of 195 eyes (116 glaucoma and 79 glaucoma suspect) of 99 patients with stereoscopic photographs and OCT scans of the optic discs taken during the same visit were compared. Optic disc photographs were read by 2 masked glaucoma specialists for VCDR and HCDR estimation. Intraclass correlation coefficient (ICC) and Bland-Altman plots were used to assess the agreement between photograph reading and OCT in estimating CDR. OCT images computed significantly larger VCDR and HCDR than photograph reading before and after stratifying eyes based on disc size (P < .001). The difference in CDR estimates between the 2 methods was equal to or greater than 0.2 in 29% and 35% of the eyes for VCDR and HCDR, respectively, with a mean difference of 0.3 in each case. The ICCs between the readers and OCT ranged between 0.50 and 0.63. The size of disagreement in VCDR correlated weakly with cup area in eyes with medium (r 2  = 0.10, P = .008) and large (r 2  = 0.09, P = .007) discs. OCT and photograph reading by clinicians agree poorly in CDR assessment. The difference in VCDR between the 2 methods was depended on cup area in medium and large discs. These differences should be considered when making conclusions regarding CDRs in clinical practice. Copyright © 2017 Elsevier Inc. All rights reserved.

EEG-based cognitive load of processing events in 3D virtual worlds is lower than processing events in 2D displays.

PubMed

Dan, Alex; Reiner, Miriam

2017-12-01

Interacting with 2D displays, such as computer screens, smartphones, and TV, is currently a part of our daily routine; however, our visual system is built for processing 3D worlds. We examined the cognitive load associated with a simple and a complex task of learning paper-folding (origami) by observing 2D or stereoscopic 3D displays. While connected to an electroencephalogram (EEG) system, participants watched a 2D video of an instructor demonstrating the paper-folding tasks, followed by a stereoscopic 3D projection of the same instructor (a digital avatar) illustrating identical tasks. We recorded the power of alpha and theta oscillations and calculated the cognitive load index (CLI) as the ratio of the average power of frontal theta (Fz.) and parietal alpha (Pz). The results showed a significantly higher cognitive load index associated with processing the 2D projection as compared to the 3D projection; additionally, changes in the average theta Fz power were larger for the 2D conditions as compared to the 3D conditions, while alpha average Pz power values were similar for 2D and 3D conditions for the less complex task and higher in the 3D state for the more complex task. The cognitive load index was lower for the easier task and higher for the more complex task in 2D and 3D. In addition, participants with lower spatial abilities benefited more from the 3D compared to the 2D display. These findings have implications for understanding cognitive processing associated with 2D and 3D worlds and for employing stereoscopic 3D technology over 2D displays in designing emerging virtual and augmented reality applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Clinical Assessment of Stereoacuity and 3-D Stereoscopic Entertainment

PubMed Central

Tidbury, Laurence P.; Black, Robert H.; O’Connor, Anna R.

2015-01-01

Abstract Background/Aims: The perception of compelling depth is often reported in individuals where no clinically measurable stereoacuity is apparent. We aim to investigate the potential cause of this finding by varying the amount of stereopsis available to the subject, and assessing their perception of depth viewing 3-D video clips and a Nintendo 3DS. Methods: Monocular blur was used to vary interocular VA difference, consequently creating 4 levels of measurable binocular deficit from normal stereoacuity to suppression. Stereoacuity was assessed at each level using the TNO, Preschool Randot®, Frisby, the FD2, and Distance Randot®. Subjects also completed an object depth identification task using the Nintendo 3DS, a static 3DTV stereoacuity test, and a 3-D perception rating task of 6 video clips. Results: As intraocular VA differences increased, stereoacuity of the 57 subjects (aged 16–62 years) decreased (eg, 110”, 280”, 340”, and suppression). The ability to correctly identify depth on the Nintendo 3DS remained at 100% until suppression of one eye occurred. The perception of a compelling 3-D effect when viewing the video clips was rated high until suppression of one eye occurred, where the 3-D effect was still reported as fairly evident. Conclusion: If an individual has any level of measurable stereoacuity, the perception of 3-D when viewing stereoscopic entertainment is present. The presence of motion in stereoscopic video appears to provide cues to depth, where static cues are not sufficient. This suggests there is a need for a dynamic test of stereoacuity to be developed, to allow fully informed patient management decisions to be made. PMID:26669421

Alternation frequency thresholds for stereopsis as a technique for exploring stereoscopic difficulties

PubMed Central

Rychkova, Svetlana; Ninio, Jacques

2011-01-01

When stereoscopic images are presented alternately to the two eyes, stereopsis occurs at F ≥ 1 Hz full-cycle frequencies for very simple stimuli, and F ≥ 3 Hz full-cycle frequencies for random-dot stereograms (eg Ludwig I, Pieper W, Lachnit H, 2007 “Temporal integration of monocular images separated in time: stereopsis, stereoacuity, and binocular luster” Perception & Psychophysics 69 92–102). Using twenty different stereograms presented through liquid crystal shutters, we studied the transition to stereopsis with fifteen subjects. The onset of stereopsis was observed during a stepwise increase of the alternation frequency, and its disappearance was observed during a stepwise decrease in frequency. The lowest F values (around 2.5 Hz) were observed with stimuli involving two to four simple disjoint elements (circles, arcs, rectangles). Higher F values were needed for stimuli containing slanted elements or curved surfaces (about 1 Hz increment), overlapping elements at two different depths (about 2.5 Hz increment), or camouflaged overlapping surfaces (> 7 Hz increment). A textured cylindrical surface with a horizontal axis appeared easier to interpret (5.7 Hz) than a pair of slanted segments separated in depth but forming a cross in projection (8 Hz). Training effects were minimal, and F usually increased as disparities were reduced. The hierarchy of difficulties revealed in the study may shed light on various problems that the brain needs to solve during stereoscopic interpretation. During the construction of the three-dimensional percept, the loss of information due to natural decay of the stimuli traces must be compensated by refreshes of visual input. In the discussion an attempt is made to link our results with recent advances in the comprehension of visual scene memory. PMID:23145225

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.

Comparison and Analysis of Accuracy of Elevation Extraction Based on the ZY-3 01 and 02 Satellites Stereoscopic Images

NASA Astrophysics Data System (ADS)

Zhao, L.; Fu, X.; Dou, X.; Liu, H.; Fang, Z.

2018-04-01

The ZY-3 is the civil high-resolution optical stereoscopic mapping satellite independently developed by China. The ZY-3 constellation of the twin satellites operates in a sun-synchronous, near-polar, circular 505 km orbit, with a descending location time of 10:30 AM and a 29-day revisiting period. The panchromatic triplet sensors, pointing forward, nadir, and backward with an angle of 22°, have excellent base-to-height ratio, which is beneficial to the extraction of DEM. In order to extract more detailed and highprecision DEM, the ZY-3 (02) satellite has been upgraded based on the ZY-3 (01), and the GSD of the stereo camera has been optimized from 3.5 to 2.5 meters. In the paper case studies using the ZY-3 01 and the 02 satellite data for block adjustment and DEM extraction have been carried out in Liaoning Province of China. The results show that the planimetric and altimetric accuracy can reach 3 meters, which meet the mapping requirements of 1 : 50,000 national topographic map and the design performance of the satellites. The normalized elevation accuracy index (NEAI) is adopted to evaluate the twin satellite stereoscopic performance, and the NEAIs of the twin ZY-3 satellites are good and the index of the ZY-3(02) is slightly better. The comparison of the overlapping DEMs from the twin ZY-3 satellites and SRTM is analysed. The bias and the standard deviation of all the DEMs are better than 5 meters. In addition, in the process of accuracy comparison, some gross errors of the DEM can be identified, and some elevation changes of the DEM can also be found. The differential DEM becomes a new tool and application.

21 CFR 886.1870 - Stereoscope.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle deviation), evaluate binocular vision (usage of both eyes to see), and guide a patient's corrective exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the...

21 CFR 886.1870 - Stereoscope.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle deviation), evaluate binocular vision (usage of both eyes to see), and guide a patient's corrective exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the...

21 CFR 886.1870 - Stereoscope.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle... exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the... current good manufacturing practice requirements of the quality system regulation in part 820 of this...

21 CFR 886.1870 - Stereoscope.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle... exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the... current good manufacturing practice requirements of the quality system regulation in part 820 of this...

21 CFR 886.1870 - Stereoscope.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-dimensional appearance of solidity and relief. It is intended to measure the angle of strabismus (eye muscle... exercises of eye muscles. (b) Classification. Class I (general controls). The AC-powered device and the... current good manufacturing practice requirements of the quality system regulation in part 820 of this...

Using a Dissecting Microscope in Teaching Introductory Chemistry.

ERIC Educational Resources Information Center

Winokur, Robert; Monroe, Manus

1985-01-01

To have students develop observational skills and acquire an excitement about chemistry, stereoscopic dissecting microscopes are used to observe the physical characteristics and chemical reactions of various substances. Several of these reactions (including dissolving potassium permanganate in deionized water and reactions between copper metal and…

Three-dimensional digital mapping of the optic nerve head cupping in glaucoma

NASA Astrophysics Data System (ADS)

Mitra, Sunanda; Ramirez, Manuel; Morales, Jose

1992-08-01

Visualization of the optic nerve head cupping is clinically achieved by stereoscopic viewing of a fundus image pair of the suspected eye. A novel algorithm for three-dimensional digital surface representation of the optic nerve head, using fusion of stereo depth map with a linearly stretched intensity image of a stereo fundus image pair, is presented. Prior to depth map acquisition, a number of preprocessing tasks including feature extraction, registration by cepstral analysis, and correction for intensity variations are performed. The depth map is obtained by using a coarse to fine strategy for obtaining disparities between corresponding areas. The required matching techniques to obtain the translational differences in every step, uses cepstral analysis and correlation-like scanning technique in the spatial domain for the finest details. The quantitative and precise representation of the optic nerve head surface topography following this algorithm is not computationally intensive and should provide more useful information than just qualitative stereoscopic viewing of the fundus as one of the diagnostic criteria for diagnosis of glaucoma.

Standardized access, display, and retrieval of medical video

NASA Astrophysics Data System (ADS)

Bellaire, Gunter; Steines, Daniel; Graschew, Georgi; Thiel, Andreas; Bernarding, Johannes; Tolxdorff, Thomas; Schlag, Peter M.

1999-05-01

The system presented here enhances documentation and data- secured, second-opinion facilities by integrating video sequences into DICOM 3.0. We present an implementation for a medical video server extended by a DICOM interface. Security mechanisms conforming with DICOM are integrated to enable secure internet access. Digital video documents of diagnostic and therapeutic procedures should be examined regarding the clip length and size necessary for second opinion and manageable with today's hardware. Image sources relevant for this paper include 3D laparoscope, 3D surgical microscope, 3D open surgery camera, synthetic video, and monoscopic endoscopes, etc. The global DICOM video concept and three special workplaces of distinct applications are described. Additionally, an approach is presented to analyze the motion of the endoscopic camera for future automatic video-cutting. Digital stereoscopic video sequences are especially in demand for surgery . Therefore DSVS are also integrated into the DICOM video concept. Results are presented describing the suitability of stereoscopic display techniques for the operating room.

Empirical Evaluation of Visual Fatigue from Display Alignment Errors Using Cerebral Hemodynamic Responses

PubMed Central

Wiyor, Hanniebey D.; Ntuen, Celestine A.

2013-01-01

The purpose of this study was to investigate the effect of stereoscopic display alignment errors on visual fatigue and prefrontal cortical tissue hemodynamic responses. We collected hemodynamic data and perceptual ratings of visual fatigue while participants performed visual display tasks on 8 ft × 6 ft NEC LT silver screen with NEC LT 245 DLP projectors. There was statistical significant difference between subjective measures of visual fatigue before air traffic control task (BATC) and after air traffic control task (ATC 3), (P < 0.05). Statistical significance was observed between left dorsolateral prefrontal cortex oxygenated hemoglobin (l DLPFC-HbO2), left dorsolateral prefrontal cortex deoxygenated hemoglobin (l DLPFC-Hbb), and right dorsolateral prefrontal cortex deoxygenated hemoglobin (r DLPFC-Hbb) on stereoscopic alignment errors (P < 0.05). Thus, cortical tissue oxygenation requirement in the left hemisphere indicates that the effect of visual fatigue is more pronounced in the left dorsolateral prefrontal cortex. PMID:27006917

Focus and perspective adaptive digital surgical microscope: optomechanical design and experimental implementation

NASA Astrophysics Data System (ADS)

Claus, Daniel; Reichert, Carsten; Herkommer, Alois

2017-05-01

This paper relates to the improvement of conventional surgical stereo microscopy via the application of digital recording devices and adaptive optics. The research is aimed at improving the working conditions of the surgeon during the operation, such that free head movement is possible. The depth clues known from conventional stereo microscopy in interaction with the human eye's functionality, such as convergence, disparity, angular elevation, parallax, and accommodation, are implemented in a digital recording system via adaptive optomechanical components. Two laterally moving pupil apertures have been used mimicking the digital implementation of the eye's vergence and head motion. The natural eye's accommodation is mimicked via the application of a tunable lens. Additionally, another system has been built, which enables tracking the surgeon's eye pupil through a digital displaying stereoscopic microscope to supply the necessary information for steering the recording system. The optomechanical design and experimental results for both systems, digital recording stereoscopic microscope and pupil tracking system, are shown.

Formalizing the potential of stereoscopic 3D user experience in interactive entertainment

NASA Astrophysics Data System (ADS)

Schild, Jonas; Masuch, Maic

2015-03-01

The use of stereoscopic 3D vision affects how interactive entertainment has to be developed as well as how it is experienced by the audience. The large amount of possibly impacting factors and variety as well as a certain subtlety of measured effects on user experience make it difficult to grasp the overall potential of using S3D vision. In a comprehensive approach, we (a) present a development framework which summarizes possible variables in display technology, content creation and human factors, and (b) list a scheme of S3D user experience effects concerning initial fascination, emotions, performance, and behavior as well as negative feelings of discomfort and complexity. As a major contribution we propose a qualitative formalization which derives dependencies between development factors and user effects. The argumentation is based on several previously published user studies. We further show how to apply this formula to identify possible opportunities and threats in content creation as well as how to pursue future steps for a possible quantification.

Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras

NASA Astrophysics Data System (ADS)

Kataoka, R.; Miyoshi, Y.; Shigematsu, K.; Hampton, D.; Mori, Y.; Kubo, T.; Yamashita, A.; Tanaka, M.; Takahei, T.; Nakai, T.; Miyahara, H.; Shiokawa, K.

2013-09-01

A new stereoscopic measurement technique is developed to obtain an all-sky altitude map of aurora using two ground-based digital single-lens reflex (DSLR) cameras. Two identical full-color all-sky cameras were set with an 8 km separation across the Chatanika area in Alaska (Poker Flat Research Range and Aurora Borealis Lodge) to find localized emission height with the maximum correlation of the apparent patterns in the localized pixels applying a method of the geographical coordinate transform. It is found that a typical ray structure of discrete aurora shows the broad altitude distribution above 100 km, while a typical patchy structure of pulsating aurora shows the narrow altitude distribution of less than 100 km. Because of its portability and low cost of the DSLR camera systems, the new technique may open a unique opportunity not only for scientists but also for night-sky photographers to complementarily attend the aurora science to potentially form a dense observation network.

Full-reference quality assessment of stereoscopic images by learning binocular receptive field properties.

PubMed

Shao, Feng; Li, Kemeng; Lin, Weisi; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

2015-10-01

Quality assessment of 3D images encounters more challenges than its 2D counterparts. Directly applying 2D image quality metrics is not the solution. In this paper, we propose a new full-reference quality assessment for stereoscopic images by learning binocular receptive field properties to be more in line with human visual perception. To be more specific, in the training phase, we learn a multiscale dictionary from the training database, so that the latent structure of images can be represented as a set of basis vectors. In the quality estimation phase, we compute sparse feature similarity index based on the estimated sparse coefficient vectors by considering their phase difference and amplitude difference, and compute global luminance similarity index by considering luminance changes. The final quality score is obtained by incorporating binocular combination based on sparse energy and sparse complexity. Experimental results on five public 3D image quality assessment databases demonstrate that in comparison with the most related existing methods, the devised algorithm achieves high consistency with subjective assessment.

Stereoscopic particle image velocimetry investigations of the mixed convection exchange flow through a horizontal vent

NASA Astrophysics Data System (ADS)

Varrall, Kevin; Pretrel, Hugues; Vaux, Samuel; Vauquelin, Olivier

2017-10-01

The exchange flow through a horizontal vent linking two compartments (one above the other) is studied experimentally. This exchange is here governed by both the buoyant natural effect due to the temperature difference of the fluids in both compartments, and the effect of a (forced) mechanical ventilation applied in the lower compartment. Such a configuration leads to uni- or bi-directional flows through the vent. In the experiments, buoyancy is induced in the lower compartment thanks to an electrical resistor. The forced ventilation is applied in exhaust or supply modes and three different values of the vent area. To estimate both velocity fields and flow rates at the vent, measurements are realized at thermal steady state, flush the vent in the upper compartment using stereoscopic particle image velocimetry (SPIV), which is original for this kind of flow. The SPIV measurements allows the area occupied by both upward and downward flows to be determined.

Contextual Cueing Effect in Spatial Layout Defined by Binocular Disparity

PubMed Central

Zhao, Guang; Zhuang, Qian; Ma, Jie; Tu, Shen; Liu, Qiang; Sun, Hong-jin

2017-01-01

Repeated visual context induces higher search efficiency, revealing a contextual cueing effect, which depends on the association between the target and its visual context. In this study, participants performed a visual search task where search items were presented with depth information defined by binocular disparity. When the 3-dimensional (3D) configurations were repeated over blocks, the contextual cueing effect was obtained (Experiment 1). When depth information was in chaos over repeated configurations, visual search was not facilitated and the contextual cueing effect largely crippled (Experiment 2). However, when we made the search items within a tiny random displacement in the 2-dimentional (2D) plane but maintained the depth information constant, the contextual cueing was preserved (Experiment 3). We concluded that the contextual cueing effect was robust in the context provided by 3D space with stereoscopic information, and more importantly, the visual system prioritized stereoscopic information in learning of spatial information when depth information was available. PMID:28912739

Collaborative learning using Internet2 and remote collections of stereo dissection images.

PubMed

Dev, Parvati; Srivastava, Sakti; Senger, Steven

2006-04-01

We have investigated collaborative learning of anatomy over Internet2, using an application called remote stereo viewer (RSV). This application offers a unique method of teaching anatomy, using high-resolution stereoscopic images, in a client-server architecture. Rotated sequences of stereo image pairs were produced by volumetric rendering of the Visible female and by dissecting and photographing a cadaveric hand. A client-server application (RSV) was created to provide access to these image sets, using a highly interactive interface. The RSV system was used to provide a "virtual anatomy" session for students in the Stanford Medical School Gross Anatomy course. The RSV application allows both independent and collaborative modes of viewing. The most appealing aspects of the RSV application were the capacity for stereoscopic viewing and the potential to access the content remotely within a flexible temporal framework. The RSV technology, used over Internet2, thus serves as an effective complement to traditional methods of teaching gross anatomy. (c) 2006 Wiley-Liss, Inc.

Video stereolization: combining motion analysis with user interaction.

PubMed

Liao, Miao; Gao, Jizhou; Yang, Ruigang; Gong, Minglun

2012-07-01

We present a semiautomatic system that converts conventional videos into stereoscopic videos by combining motion analysis with user interaction, aiming to transfer as much as possible labeling work from the user to the computer. In addition to the widely used structure from motion (SFM) techniques, we develop two new methods that analyze the optical flow to provide additional qualitative depth constraints. They remove the camera movement restriction imposed by SFM so that general motions can be used in scene depth estimation-the central problem in mono-to-stereo conversion. With these algorithms, the user's labeling task is significantly simplified. We further developed a quadratic programming approach to incorporate both quantitative depth and qualitative depth (such as these from user scribbling) to recover dense depth maps for all frames, from which stereoscopic view can be synthesized. In addition to visual results, we present user study results showing that our approach is more intuitive and less labor intensive, while producing 3D effect comparable to that from current state-of-the-art interactive algorithms.

Field-Sequential Electronic Stereoscopic Projector

NASA Astrophysics Data System (ADS)

Lipton, Lenny

1989-07-01

Culminating a research and development project spanning many years, StereoGraphics Corporation has succeeded in bringing to market the first field-sequential electronic stereoscopic projector. The product is based on a modification of Electrohome and Barco projectors. Our design goal was to produce a projector capable of displaying an image on a six-foot (or larger) diagonal screen for an audience of 50 or 60 people, or for an individual using a simulator. A second goal was to produce an image that required only passive polarizing glasses rather than powered, tethered visors. Two major design challenges posed themselves. First, it was necessary to create an electro-optical modulator which could switch the characteristic of polarized light at field rate, and second, it was necessary to produce a bright green CRT with short persistence to prevent crosstalk between left and right fields. To solve the first problem, development was undertaken to produce the required electro-optical modulator. The second problem was solved with the help of a vendor specializing in high performance CRT's.

Measurement of compressed breast thickness by optical stereoscopic photogrammetry.

PubMed

Tyson, Albert H; Mawdsley, Gordon E; Yaffe, Martin J

2009-02-01

The determination of volumetric breast density (VBD) from mammograms requires accurate knowledge of the thickness of the compressed breast. In attempting to accurately determine VBD from images obtained on conventional mammography systems, the authors found that the thickness reported by a number of mammography systems in the field varied by as much as 15 mm when compressing the same breast or phantom. In order to evaluate the behavior of mammographic compression systems and to be able to predict the thickness at different locations in the breast on patients, they have developed a method for measuring the local thickness of the breast at all points of contact with the compression paddle using optical stereoscopic photogrammetry. On both flat (solid) and compressible phantoms, the measurements were accurate to better than 1 mm with a precision of 0.2 mm. In a pilot study, this method was used to measure thickness on 108 volunteers who were undergoing mammography examination. This measurement tool will allow us to characterize paddle surface deformations, deflections and calibration offsets for mammographic units.

The Advanced Gamma-ray Imaging System (AGIS): Real Time Stereoscopic Array Trigger

NASA Astrophysics Data System (ADS)

Byrum, K.; Anderson, J.; Buckley, J.; Cundiff, T.; Dawson, J.; Drake, G.; Duke, C.; Haberichter, B.; Krawzcynski, H.; Krennrich, F.; Madhavan, A.; Schroedter, M.; Smith, A.

2009-05-01

Future large arrays of Imaging Atmospheric Cherenkov telescopes (IACTs) such as AGIS and CTA are conceived to comprise of 50 - 100 individual telescopes each having a camera with 10**3 to 10**4 pixels. To maximize the capabilities of such IACT arrays with a low energy threshold, a wide field of view and a low background rate, a sophisticated array trigger is required. We describe the design of a stereoscopic array trigger that calculates image parameters and then correlates them across a subset of telescopes. Fast Field Programmable Gate Array technology allows to use lookup tables at the array trigger level to form a real-time pattern recognition trigger tht capitalizes on the multiple view points of the shower at different shower core distances. A proof of principle system is currently under construction. It is based on 400 MHz FPGAs and the goal is for camera trigger rates of up to 10 MHz and a tunable cosmic-ray background suppression at the array level.

Statis omnidirectional stereoscopic display system

NASA Astrophysics Data System (ADS)

Barton, George G.; Feldman, Sidney; Beckstead, Jeffrey A.

1999-11-01

A unique three camera stereoscopic omnidirectional viewing system based on the periscopic panoramic camera described in the 11/98 SPIE proceedings (AM13). The 3 panoramic cameras are equilaterally combined so each leg of the triangle approximates the human inter-ocular spacing allowing each panoramic camera to view 240 degree(s) of the panoramic scene, the most counter clockwise 120 degree(s) being the left eye field and the other 120 degree(s) segment being the right eye field. Field definition may be by green/red filtration or time discrimination of the video signal. In the first instance a 2 color spectacle is used in viewing the display or in the 2nd instance LCD goggles are used to differentiate the R/L fields. Radially scanned vidicons or re-mapped CCDs may be used. The display consists of three vertically stacked 120 degree(s) segments of the panoramic field of view with 2 fields/frame. Field A being the left eye display and Field B the right eye display.

Stereoscopic, thermal, and true deep cumulus cloud top heights

NASA Astrophysics Data System (ADS)

Llewellyn-Jones, D. T.; Corlett, G. K.; Lawrence, S. P.; Remedios, J. J.; Sherwood, S. C.; Chae, J.; Minnis, P.; McGill, M.

2004-05-01

We compare cloud-top height estimates from several sensors: thermal tops from GOES-8 and MODIS, stereoscopic tops from MISR, and directly measured heights from the Goddard Cloud Physics Lidar on board the ER-2, all collected during the CRYSTAL-FACE field campaign. Comparisons reveal a persistent 1-2 km underestimation of cloud-top heights by thermal imagery, even when the finite optical extinctions near cloud top and in thin overlying cirrus are taken into account. The most severe underestimates occur for the tallest clouds. The MISR "best-sinds" and lidar estimates disagree in very similar ways with thermally estimated tops, which we take as evidence of excellent performance by MISR. Encouraged by this, we use MISR to examine variations in cloud penetration and thermal top height errors in several locations of tropical deep convection over multiple seasons. The goals of this are, first, to learn how cloud penetration depends on the near-tropopause environment; and second, to gain further insight into the mysterious underestimation of tops by thermal imagery.

Contextual Cueing Effect in Spatial Layout Defined by Binocular Disparity.

PubMed

Zhao, Guang; Zhuang, Qian; Ma, Jie; Tu, Shen; Liu, Qiang; Sun, Hong-Jin

2017-01-01

Repeated visual context induces higher search efficiency, revealing a contextual cueing effect, which depends on the association between the target and its visual context. In this study, participants performed a visual search task where search items were presented with depth information defined by binocular disparity. When the 3-dimensional (3D) configurations were repeated over blocks, the contextual cueing effect was obtained (Experiment 1). When depth information was in chaos over repeated configurations, visual search was not facilitated and the contextual cueing effect largely crippled (Experiment 2). However, when we made the search items within a tiny random displacement in the 2-dimentional (2D) plane but maintained the depth information constant, the contextual cueing was preserved (Experiment 3). We concluded that the contextual cueing effect was robust in the context provided by 3D space with stereoscopic information, and more importantly, the visual system prioritized stereoscopic information in learning of spatial information when depth information was available.

Development of a stereoscopic three-dimensional drawing application

NASA Astrophysics Data System (ADS)

Carver, Donald E.; McAllister, David F.

1991-08-01

With recent advances in 3-D technology, computer users have the opportunity to work within a natural 3-D environment; a flat panel LCD computer display of this type, the DTI-100M made by Dimension Technologies, Inc., recently went on the market. In a joint venture between DTI and NCSU, an object-oriented 3-D drawing application, 3-D Draw, was developed to address some issues of human interface design for interactive stereo drawing applications. The focus of this paper is to determine some of the procedures a user would naturally expect to follow while working within a true 3-D environment. The paper discusses (1) the interface between the Macintosh II and DTI-100M during implementation of 3-D Draw, including stereo cursor development and presentation of current 2-D systems, with an additional `depth'' parameter, in the 3-D world, (2) problems in general for human interface into the 3-D environment, and (3) necessary functions and/or problems in developing future stereoscopic 3-D operating systems/tools.

Variational stereo imaging of oceanic waves with statistical constraints.

PubMed

Gallego, Guillermo; Yezzi, Anthony; Fedele, Francesco; Benetazzo, Alvise

2013-11-01

An image processing observational technique for the stereoscopic reconstruction of the waveform of oceanic sea states is developed. The technique incorporates the enforcement of any given statistical wave law modeling the quasi-Gaussianity of oceanic waves observed in nature. The problem is posed in a variational optimization framework, where the desired waveform is obtained as the minimizer of a cost functional that combines image observations, smoothness priors and a weak statistical constraint. The minimizer is obtained by combining gradient descent and multigrid methods on the necessary optimality equations of the cost functional. Robust photometric error criteria and a spatial intensity compensation model are also developed to improve the performance of the presented image matching strategy. The weak statistical constraint is thoroughly evaluated in combination with other elements presented to reconstruct and enforce constraints on experimental stereo data, demonstrating the improvement in the estimation of the observed ocean surface.

Identification and visualisation of possible ancient ocean shoreline on Mars using submeter-resolution Digital Terrain Models

NASA Astrophysics Data System (ADS)

Świąder, Andrzej

2014-12-01

Digital Terrain Models (DTMs) produced from stereoscopic, submeter-resolution High Resolution Imaging Science Experiment (HiRISE) imagery provide a solid basis for all morphometric analyses of the surface of Mars. In view of the fact that a more effective use of DTMs is hindered by complicated and time-consuming manual handling, the automated process provided by specialists of the Ames Intelligent Robotics Group (NASA), Ames Stereo Pipeline, constitutes a good alternative. Four DTMs, covering the global dichotomy boundary between the southern highlands and northern lowlands along the line of the presumable Arabia shoreline, were produced and analysed. One of them included forms that are likely to be indicative of an oceanic basin that extended across the lowland northern hemisphere of Mars in the geological past. The high resolution DTMs obtained were used in the process of landscape visualisation.

Spectral study of the HESS J1745-290 gamma-ray source as dark matter signal

NASA Astrophysics Data System (ADS)

Cembranos, J. A. R.; Gammaldi, V.; Maroto, A. L.

2013-04-01

We study the main spectral features of the gamma-ray fluxes observed by the High Energy Stereoscopic System (HESS) from the J1745-290 Galactic Center source during the years 2004, 2005 and 2006. In particular, we show that these data are well fitted as the secondary gamma-rays photons generated from dark matter annihilating into Standard Model particles in combination with a simple power law background. We present explicit analyses for annihilation in a single standard model particle-antiparticle pair. In this case, the best fits are obtained for the uū and dbar d quark channels and for the W+W- and ZZ gauge bosons, with background spectral index compatible with the Fermi-Large Area Telescope (LAT) data from the same region. The fits return a heavy WIMP, with a mass above ~ 10 TeV, but well below the unitarity limit for thermal relic annihilation.

Measuring earthquakes from optical satellite images.

PubMed

Van Puymbroeck, N; Michel, R; Binet, R; Avouac, J P; Taboury, J

2000-07-10

Système pour l'Observation de la Terre images are used to map ground displacements induced by earthquakes. Deformations (offsets) induced by stereoscopic effect and roll, pitch, and yaw of satellite and detector artifacts are estimated and compensated. Images are then resampled in a cartographic projection with a low-bias interpolator. A subpixel correlator in the Fourier domain provides two-dimensional offset maps with independent measurements approximately every 160 m. Biases on offsets are compensated from calibration. High-frequency noise (0.125 m(-1)) is approximately 0.01 pixels. Low-frequency noise (lower than 0.001 m(-1)) exceeds 0.2 pixels and is partially compensated from modeling. Applied to the Landers earthquake, measurements show the fault with an accuracy of a few tens of meters and yields displacement on the fault with an accuracy of better than 20 cm. Comparison with a model derived from geodetic data shows that offsets bring new insights into the faulting process.

Distributed volume rendering and stereoscopic display for radiotherapy treatment planning

NASA Astrophysics Data System (ADS)

Hancock, David J.

The thesis describes attempts to use direct volume rendering techniques to produce visualisations useful in the preparation of radiotherapy treatment plans. The selected algorithms allow the generation of data-rich images which can be used to assist the radiologist in comprehending complicated three-dimensional phenomena. The treatment plans are formulated using a three dimensional model which combines patient data acquired from CT scanning and the results of a simulation of the radiation delivery. Multiple intersecting beams with shaped profiles are used and the region of intersection is designed to closely match the position and shape of the targeted tumour region. The proposed treatment must be evaluated as to how well the target region is enveloped by the high dose occurring where the beams intersect, and also as to whether the treatment is likely to expose non-tumour regions to unacceptably high levels of radiation. Conventionally the plans are reviewed by examining CT images overlaid with contours indicating dose levels. Volume visualisation offers a possible saving in time by presenting the data in three dimensional form thereby removing the need to examine a set of slices. The most difficult aspect is to depict unambiguously the relationships between the different data. For example, if a particular beam configuration results in unintended irradiation of a sensitive organ, then it is essential to ensure that this is clearly displayed, and that the 3D relationships between the beams and other data can be readily perceived in order to decide how to correct the problem. The user interface has been designed to present a unified view of the different techniques available for identifying features of interest within the data. The system differs from those previously reported in that complex visualisations can be constructed incrementally, and several different combinations of features can be viewed simultaneously. To maximise the quantity of relevant data presented in a single view, large regions of the data are rendered very transparently. This is done to ensure that interesting features buried deep within the data are visible from any viewpoint. Rendering images with high degrees of transparency raises a number of problems, primarily the drop in quality of depth cues in the image, but also the increase in computational requirements over surface-based visualisations. One solution to the increase in image generation times is the use of parallel architectures, which are an attractive platform for large visualisation tasks such as this. A parallel implementation of the direct volume rendering algorithm is described and its performance is evaluated. Several issues must be addressed in implementing an interactive rendering system in a distributed computing environment: principally overcoming the latency and limited bandwidth of the typical network connection. This thesis reports a pipelining strategy developed to improve the level of interactivity in such situations. Stereoscopic image presentation offers a method to offset the reduction in clarity of the depth information in the transparent images. The results of an investigation into the effectiveness of stereoscopic display as an aid to perception in highly transparent images are presented. Subjects were shown scenes of a synthetic test data set in which conventional depth cues were very limited. The experiments were designed to discover what effect stereoscopic viewing of the transparent, volume rendered images had on user's depth perception.

A medaka model of cancer allowing direct observation of transplanted tumor cells in vivo at a cellular-level resolution.

PubMed

Hasegawa, Sumitaka; Maruyama, Kouichi; Takenaka, Hikaru; Furukawa, Takako; Saga, Tsuneo

2009-08-18

The recent success with small fish as an animal model of cancer with the aid of fluorescence technique has attracted cancer modelers' attention because it would be possible to directly visualize tumor cells in vivo in real time. Here, we report a medaka model capable of allowing the observation of various cell behaviors of transplanted tumor cells, such as cell proliferation and metastasis, which were visualized easily in vivo. We established medaka melanoma (MM) cells stably expressing GFP and transplanted them into nonirradiated and irradiated medaka. The tumor cells were grown at the injection sites in medaka, and the spatiotemporal changes were visualized under a fluorescence stereoscopic microscope at a cellular-level resolution, and even at a single-cell level. Tumor dormancy and metastasis were also observed. Interestingly, in irradiated medaka, accelerated tumor growth and metastasis of the transplanted tumor cells were directly visualized. Our medaka model provides an opportunity to visualize in vivo tumor cells "as seen in a culture dish" and would be useful for in vivo tumor cell biology.

Near wall turbulence: An experimental view

NASA Astrophysics Data System (ADS)

Stanislas, Michel

2017-10-01

The present paper draws upon the experience of the author to illustrate the potential of advanced optical metrology for understanding near-wall-turbulence physics. First the canonical flat plate boundary layer problem is addressed, initially very near to the wall and then in the outer region when the Reynolds number is high enough to generate an outer turbulence peak. The coherent structure organization is examined in detail with the help of stereoscopic particle image velocimetry (PIV). Then the case of a turbulent boundary layer subjected to a mild adverse pressure gradient is considered. The results obtained show the great potential of a joint experimental-numerical approach. The conclusion is that the insight provided by today's optical metrology opens the way for significant improvements in turbulence modeling in upcoming years.

Colour stereociné photography with twin cameras through the operation microscope.

PubMed

Phillips, C I; McDonald, A J

1975-01-01

Two Beaulieu R16 cinecameras attached toa Zeiss operation microscope, OP Mi2, one for each side, produced colour cine films. When these were projected through polarizing filters on to a silver screen, the audience (wearing appropriately oriented polarizing spectacles) achieved a stereoscopic view.

An evaluation of lithographed forest stereograms.

Treesearch

David A. Bernstein

1961-01-01

Aerial photo stereograms are valuable for showing neophyte photo interpreters the stereoscopic appearance of common objects and conditions. They are also useful for instruction in measuring heights, horizontal distances, and angles on photos. Collections of stereograms of known conditions are worthwhile reference material for interpretation work in unknown areas.

[Virtual reality in ophthalmological education].

PubMed

Wagner, C; Schill, M; Hennen, M; Männer, R; Jendritza, B; Knorz, M C; Bender, H J

2001-04-01

We present a computer-based medical training workstation for the simulation of intraocular eye surgery. The surgeon manipulates two original instruments inside a mechanical model of the eye. The instrument positions are tracked by CCD cameras and monitored by a PC which renders the scenery using a computer-graphic model of the eye and the instruments. The simulator incorporates a model of the operation table, a mechanical eye, three CCD cameras for the position tracking, the stereo display, and a computer. The three cameras are mounted under the operation table from where they can observe the interior of the mechanical eye. Using small markers the cameras recognize the instruments and the eye. Their position and orientation in space is determined by stereoscopic back projection. The simulation runs with more than 20 frames per second and provides a realistic impression of the surgery. It includes the cold light source which can be moved inside the eye and the shadow of the instruments on the retina which is important for navigational purposes.

Real-time three-dimensional soft tissue reconstruction for laparoscopic surgery.

PubMed

Kowalczuk, Jędrzej; Meyer, Avishai; Carlson, Jay; Psota, Eric T; Buettner, Shelby; Pérez, Lance C; Farritor, Shane M; Oleynikov, Dmitry

2012-12-01

Accurate real-time 3D models of the operating field have the potential to enable augmented reality for endoscopic surgery. A new system is proposed to create real-time 3D models of the operating field that uses a custom miniaturized stereoscopic video camera attached to a laparoscope and an image-based reconstruction algorithm implemented on a graphics processing unit (GPU). The proposed system was evaluated in a porcine model that approximates the viewing conditions of in vivo surgery. To assess the quality of the models, a synthetic view of the operating field was produced by overlaying a color image on the reconstructed 3D model, and an image rendered from the 3D model was compared with a 2D image captured from the same view. Experiments conducted with an object of known geometry demonstrate that the system produces 3D models accurate to within 1.5 mm. The ability to produce accurate real-time 3D models of the operating field is a significant advancement toward augmented reality in minimally invasive surgery. An imaging system with this capability will potentially transform surgery by helping novice and expert surgeons alike to delineate variance in internal anatomy accurately.

Spatial Visualization Ability and Laparoscopic Skills in Novice Learners: Evaluating Stereoscopic versus Monoscopic Visualizations

ERIC Educational Resources Information Center

Roach, Victoria A.; Mistry, Manisha R.; Wilson, Timothy D.

2014-01-01

Elevated spatial visualization ability (Vz) is thought to influence surgical skill acquisition and performance. Current research suggests that stereo visualization technology and its association with skill performance may confer perceptual advantages. This is of particular interest in laparoscopic skill training, where stereo visualization may…

The Use of Haptic Display Technology in Education

ERIC Educational Resources Information Center

Barfield, Woodrow

2009-01-01

The experience of "virtual reality" can consist of head-tracked and stereoscopic virtual worlds, spatialized sound, haptic feedback, and to a lesser extent olfactory cues. Although virtual reality systems have been proposed for numerous applications, the field of education is one particular application that seems well-suited for virtual…

Preliminary experience with a stereoscopic video system in a remotely piloted aircraft application

NASA Technical Reports Server (NTRS)

Rezek, T. W.

1983-01-01

Remote piloting video display development at the Dryden Flight Research Facility of NASA's Ames Research Center is summarized, and the reasons for considering stereo television are presented. Pertinent equipment is described. Limited flight experience is also discussed, along with recommendations for further study.

TOPSAT: Global space topographic mission

NASA Technical Reports Server (NTRS)

Vetrella, Sergio

1993-01-01

Viewgraphs on TOPSAT Global Space Topographic Mission are presented. Topics covered include: polar region applications; terrestrial ecosystem applications; stereo electro-optical sensors; space-based stereoscopic missions; optical stereo approach; radar interferometry; along track interferometry; TOPSAT-VISTA system approach; ISARA system approach; topographic mapping laser altimeter; and role of multi-beam laser altimeter.

Stereo View of Phoenix Test Sample Site

NASA Image and Video Library

2008-06-02

This anaglyph image, acquired by NASA’s Phoenix Lander’s Surface Stereo Imager on June 1, 2008, shows a stereoscopic 3D view of the so-called Knave of Hearts first-dig test area to the north of the lander. 3D glasses are necessary to view this image.

Stereoscopic processing of crossed and uncrossed disparities in the human visual cortex.

PubMed

Li, Yuan; Zhang, Chuncheng; Hou, Chunping; Yao, Li; Zhang, Jiacai; Long, Zhiying

2017-12-21

Binocular disparity provides a powerful cue for depth perception in a stereoscopic environment. Despite increasing knowledge of the cortical areas that process disparity from neuroimaging studies, the neural mechanism underlying disparity sign processing [crossed disparity (CD)/uncrossed disparity (UD)] is still poorly understood. In the present study, functional magnetic resonance imaging (fMRI) was used to explore different neural features that are relevant to disparity-sign processing. We performed an fMRI experiment on 27 right-handed healthy human volunteers by using both general linear model (GLM) and multi-voxel pattern analysis (MVPA) methods. First, GLM was used to determine the cortical areas that displayed different responses to different disparity signs. Second, MVPA was used to determine how the cortical areas discriminate different disparity signs. The GLM analysis results indicated that shapes with UD induced significantly stronger activity in the sub-region (LO) of the lateral occipital cortex (LOC) than those with CD. The results of MVPA based on region of interest indicated that areas V3d and V3A displayed higher accuracy in the discrimination of crossed and uncrossed disparities than LOC. The results of searchlight-based MVPA indicated that the dorsal visual cortex showed significantly higher prediction accuracy than the ventral visual cortex and the sub-region LO of LOC showed high accuracy in the discrimination of crossed and uncrossed disparities. The results may suggest the dorsal visual areas are more discriminative to the disparity signs than the ventral visual areas although they are not sensitive to the disparity sign processing. Moreover, the LO in the ventral visual cortex is relevant to the recognition of shapes with different disparity signs and discriminative to the disparity sign.

Bimanual Interaction with Interscopic Multi-Touch Surfaces

NASA Astrophysics Data System (ADS)

Schöning, Johannes; Steinicke, Frank; Krüger, Antonio; Hinrichs, Klaus; Valkov, Dimitar

Multi-touch interaction has received considerable attention in the last few years, in particular for natural two-dimensional (2D) interaction. However, many application areas deal with three-dimensional (3D) data and require intuitive 3D interaction techniques therefore. Indeed, virtual reality (VR) systems provide sophisticated 3D user interface, but then lack efficient 2D interaction, and are therefore rarely adopted by ordinary users or even by experts. Since multi-touch interfaces represent a good trade-off between intuitive, constrained interaction on a touch surface providing tangible feedback, and unrestricted natural interaction without any instrumentation, they have the potential to form the foundation of the next generation user interface for 2D as well as 3D interaction. In particular, stereoscopic display of 3D data provides an additional depth cue, but until now the challenges and limitations for multi-touch interaction in this context have not been considered. In this paper we present new multi-touch paradigms and interactions that combine both traditional 2D interaction and novel 3D interaction on a touch surface to form a new class of multi-touch systems, which we refer to as interscopic multi-touch surfaces (iMUTS). We discuss iMUTS-based user interfaces that support interaction with 2D content displayed in monoscopic mode and 3D content usually displayed stereoscopically. In order to underline the potential of the proposed iMUTS setup, we have developed and evaluated two example interaction metaphors for different domains. First, we present intuitive navigation techniques for virtual 3D city models, and then we describe a natural metaphor for deforming volumetric datasets in a medical context.

Pilot study completed: Paving the way for stereoscopic DEMs, orthophotos and vector maps over the ice-free parts of Greenland

NASA Astrophysics Data System (ADS)

Levinsen, Joanna F.; Borgstrøm, Rasmus E.

2017-04-01

We present the work towards developing new Digital Elevation Models (DEMs), orthophotos, and vector maps over the ice-free parts of Greenland. The products will be based on high-resolution stereoscopic images co-registered to Ground Control Points (GCPs) to reduce horizontal and vertical errors. Here, we provide a status overview of our achievements wrt. DEMs and orthophotos. We have conducted a pilot study in which four areas have been mapped using SPOT-6 and -7 images: The Disko Bay, Narsaq, Tasiilaq, and Zackenberg. The images have been acquired in 2016, with a few additions from 2014, and the areas cover approximately 82.000 km2, i.e. ˜20% of the total ice-free area. The technical requirements for the products have been defined in close collaboration with end-users from governmental institutions, emergency management offices, the tourist industry, etc., to ensure a direct applicability following product completion. This has resulted in 8 m DEMs and 1.5 m orthophotos. Validation against GCPs shows horizontal and vertical offsets of approximately 0.5 ± 2 m, i.e. values that meet our expectations and satisfy end-user needs. The GCPs make out an extensive network of huts, helipads, ports, large boulders, etc., measured using GPS by collaborators during field campaigns. The experiences gained in the product development as well as the broad range of collaborations provides confidence that the set-up for a production of the total ice-free area has been established, which can deliver products with a high accuracy in time and space. That will make them useful for a wide range of purposes. The next step therefore is to secure the given upgrade. More on that to come!

Automatic relative RPC image model bias compensation through hierarchical image matching for improving DEM quality

NASA Astrophysics Data System (ADS)

Noh, Myoung-Jong; Howat, Ian M.

2018-02-01

The quality and efficiency of automated Digital Elevation Model (DEM) extraction from stereoscopic satellite imagery is critically dependent on the accuracy of the sensor model used for co-locating pixels between stereo-pair images. In the absence of ground control or manual tie point selection, errors in the sensor models must be compensated with increased matching search-spaces, increasing both the computation time and the likelihood of spurious matches. Here we present an algorithm for automatically determining and compensating the relative bias in Rational Polynomial Coefficients (RPCs) between stereo-pairs utilizing hierarchical, sub-pixel image matching in object space. We demonstrate the algorithm using a suite of image stereo-pairs from multiple satellites over a range stereo-photogrammetrically challenging polar terrains. Besides providing a validation of the effectiveness of the algorithm for improving DEM quality, experiments with prescribed sensor model errors yield insight into the dependence of DEM characteristics and quality on relative sensor model bias. This algorithm is included in the Surface Extraction through TIN-based Search-space Minimization (SETSM) DEM extraction software package, which is the primary software used for the U.S. National Science Foundation ArcticDEM and Reference Elevation Model of Antarctica (REMA) products.

Laser photodynamic therapy of cancer: the chorioallantoic membrane model for measuring damage to blood vessels in-vivo

NASA Astrophysics Data System (ADS)

Gottfried, Varda; Lindenbaum, Ella S.; Kimel, Sol; Hammer-Wilson, Marie J.; Berns, Michael W.

1991-04-01

The mechanism of photodynamic therapy (PDT) involves, as a primary step, damage either directly to the tumor cells or to the surrounding vasculature which, in turn, causes disruption of tumor blood flow and, ultimately, tissue necrosis by anoxia. We report here a novel in-vivo model for investigating vascular events during PDT. The chick chorioallantoic membrane (CAM) model was chosen since it is an established model for studying biological processes such as implantation and angiogenesis . The photosensitizers meso-tetraphenylporphine tetrasulfonate (TPPSJ and chloro-aluminum phthalocyanine tetrasulfonate (CAPcS) were topically applied onto the CAM. In all cases where sensitizer plus radiation was administered, changes in the CAM microcirculation occurred, as viewed through a stereoscopic microscope. With increasing light/drug dose we observed capillary leakage, stasis, occlusion, hemorrhage, and engorgement. The course of damage formation was documented in real time by video photography. All controls (sensitizer alone or light alone) remained unchanged compared to treated CAM. This work also describes preliminary experiments on tumor cells transplanted onto the CAM.

Topographic instructions, Book 3, multiplex procedure; Chapter 3 C7a-e

USGS Publications Warehouse

Loud, Edward I.

1952-01-01

By direct projection of overlapping photographs, printed on glass plates, the multiplex produces an exact optical model, in miniature, of the terrain to be mapped. To create the model, the multiplex projectors must be properly positioned and oriented so that they duplicate the orientation of the aerial camera at the instant of each exposure. By means of a floating mark, horizontal and vertical measurements can be made in the model, and planimetry and contours can be drawn. The applicability of the multiplex to a given mapping project depends largely on the contour interval and compilation scale required, and also depends, to a lesser extent, on the vegetation and terrain cover as it may affect accuracy requirements. The steps in multiplex procedure are orientation, stereotriangulation, and compilation of detail. In orientation, the projectors are arranged so that the projected images form a stereoscopic model which can be adjusted to fit horizontal and vertical control points. In stereotriangulation, three or more multiplex projectors are oriented so that the consecutive models fit existing control, permitting the establishment of additional or intermediate control. In compilation, the features appearing in the model are delineated on the map manuscript.

Ten Triangles around Cavernous Sinus for Surgical Approach, Described by Schematic Diagram and Three Dimensional Models with the Sectioned Images.

PubMed

Chung, Beom Sun; Ahn, Young Hwan; Park, Jin Seo

2016-09-01

For the surgical approach to lesions around the cavernous sinus (CS), triangular spaces around CS have been devised. However, educational materials for learning the triangles were insufficient. The purpose of this study is to present educational materials about the triangles, consisting of a schematic diagram and 3-dimensional (3D) models with sectioned images. To achieve the purposes, other studies were analyzed to establish new definitions and names of the triangular spaces. Learning materials including schematic diagrams and 3D models with cadaver's sectioned images were manufactured. Our new definition was attested by observing the sectioned images and 3D models. The triangles and the four representative surgical approaches were stereoscopically indicated on the 3D models. All materials of this study were put into Portable Document Format file and were distributed freely at our homepage (anatomy.dongguk.ac.kr/triangles). By using our schematic diagram and the 3D models with sectioned images, ten triangles and the related structures could be understood and observed accurately. We expect that our data will contribute to anatomy education, surgery training, and radiologic understanding of the triangles and related structures.

Evaluation of Skylab (EREP) data for forest and rangeland surveys

Treesearch

Robert C. Aldrich

1976-01-01

Data products from the Skylab Earth Resources Experiment Package were examined monocularly or stereoscopically using a variety of magnifying interpretation devices. Land use, forest types, physiographic sites, and plant communities, as well as forest stress, were interpreted and mapped at sites in Georgia, South Dakota, and Colorado. Microdensitometric techniques and...

Real Image Visual Display System

DTIC Science & Technology

1992-12-01

DTI-100M autostereoscopic display ......................... 15 8. Lenticular screen ........ ............................. 16 9. Lenticular screen...parameters and pixel position ................. 17 10. General viewing of the stereoscopic couple .................... 18 11. Viewing zones for lenticular ...involves using a lenticular screen for imaging. Lenticular screens are probably most familiar in the form of ŗ-D postcards" which 15 consist of an

Pathways for Learning from 3D Technology

ERIC Educational Resources Information Center

Carrier, L. Mark; Rab, Saira S.; Rosen, Larry D.; Vasquez, Ludivina; Cheever, Nancy A.

2012-01-01

The purpose of this study was to find out if 3D stereoscopic presentation of information in a movie format changes a viewer's experience of the movie content. Four possible pathways from 3D presentation to memory and learning were considered: a direct connection based on cognitive neuroscience research; a connection through "immersion"…

Study on an Interactive Truck Crane Simulation Platform Based on Virtual Reality Technology

ERIC Educational Resources Information Center

Sang, Yong; Zhu, Yu; Zhao, Honghua; Tang, Mingyan

2016-01-01

The modern web-based distance education overcomes space-time restriction of the traditional teaching forms. However, being short of specifically observable and operable experimental equipment makes the web-based education lack advantages in the knowledge learning progress, which needs strong stereoscopic effect and operability. Truck crane is the…

Stereo Orthogonal Axonometric Perspective for the Teaching of Descriptive Geometry

ERIC Educational Resources Information Center

Méxas, José Geraldo Franco; Guedes, Karla Bastos; Tavares, Ronaldo da Silva

2015-01-01

Purpose: The purpose of this paper is to present the development of a software for stereo visualization of geometric solids, applied to the teaching/learning of Descriptive Geometry. Design/methodology/approach: The paper presents the traditional method commonly used in computer graphic stereoscopic vision (implemented in C language) and the…

Stereoscopic displays for virtual reality in the car manufacturing industry: application to design review and ergonomic studies

NASA Astrophysics Data System (ADS)

Moreau, Guillaume; Fuchs, Philippe

2002-05-01

In the car manufacturing industry the trend is to drastically reduce the time-to-market by increasing the use of the Digital Mock-up instead of physical prototypes. Design review and ergonomic studies are specific tasks because they involve qualitative or even subjective judgements. In this paper, we present IMAVE (IMmersion Adapted to a VEhicle) designed for immersive styling review, gaps visualization and simple ergonomic studies. We show that stereoscopic displays are necessary and must fulfill several constraints due to the proximity and size of the car dashboard. The duration fo the work sessions forces us to eliminate all vertical parallax, and 1:1 scale is obviously required for a valid immersion. Two demonstrators were realized allowing us to have a large set of testers (over 100). More than 80% of the testers saw an immediate use of the IMAVE system. We discuss the good and bad marks awarded to the system. Future work include being able to use several rear-projected stereo screens for doors and central console visualization, but without the parallax presently visible in some CAVE-like environments.

Case study: Beauty and the Beast 3D: benefits of 3D viewing for 2D to 3D conversion

NASA Astrophysics Data System (ADS)

Handy Turner, Tara

2010-02-01

From the earliest stages of the Beauty and the Beast 3D conversion project, the advantages of accurate desk-side 3D viewing was evident. While designing and testing the 2D to 3D conversion process, the engineering team at Walt Disney Animation Studios proposed a 3D viewing configuration that not only allowed artists to "compose" stereoscopic 3D but also improved efficiency by allowing artists to instantly detect which image features were essential to the stereoscopic appeal of a shot and which features had minimal or even negative impact. At a time when few commercial 3D monitors were available and few software packages provided 3D desk-side output, the team designed their own prototype devices and collaborated with vendors to create a "3D composing" workstation. This paper outlines the display technologies explored, final choices made for Beauty and the Beast 3D, wish-lists for future development and a few rules of thumb for composing compelling 2D to 3D conversions.

Remote operation: a selective review of research into visual depth perception.

PubMed

Reinhardt-Rutland, A H

1996-07-01

Some perceptual motor operations are performed remotely; examples include the handling of life-threatening materials and surgical procedures. A camera conveys the site of operation to a TV monitor, so depth perception relies mainly on pictorial information, perhaps with enhancement of the occlusion cue by motion. However, motion information such as motion parallax is not likely to be important. The effectiveness of pictorial information is diminished by monocular and binocular information conveying flatness of the screen and by difficulties in scaling: Only a degree of relative depth can be conveyed. Furthermore, pictorial information can mislead. Depth perception is probably adequate in remote operation, if target objects are well separated, with well-defined edges and familiar shapes. Stereoscopic viewing systems are being developed to introduce binocular information to remote operation. However, stereoscopic viewing is problematic because binocular disparity conflicts with convergence and monocular information. An alternative strategy to improve precision in remote operation may be to rely on individuals who lack binocular function: There is redundancy in depth information, and such individuals seem to compensate for the lack of binocular function.

The (In)Effectiveness of Simulated Blur for Depth Perception in Naturalistic Images.

PubMed

Maiello, Guido; Chessa, Manuela; Solari, Fabio; Bex, Peter J

2015-01-01

We examine depth perception in images of real scenes with naturalistic variation in pictorial depth cues, simulated dioptric blur and binocular disparity. Light field photographs of natural scenes were taken with a Lytro plenoptic camera that simultaneously captures images at up to 12 focal planes. When accommodation at any given plane was simulated, the corresponding defocus blur at other depth planes was extracted from the stack of focal plane images. Depth information from pictorial cues, relative blur and stereoscopic disparity was separately introduced into the images. In 2AFC tasks, observers were required to indicate which of two patches extracted from these images was farther. Depth discrimination sensitivity was highest when geometric and stereoscopic disparity cues were both present. Blur cues impaired sensitivity by reducing the contrast of geometric information at high spatial frequencies. While simulated generic blur may not assist depth perception, it remains possible that dioptric blur from the optics of an observer's own eyes may be used to recover depth information on an individual basis. The implications of our findings for virtual reality rendering technology are discussed.

The (In)Effectiveness of Simulated Blur for Depth Perception in Naturalistic Images

PubMed Central

Maiello, Guido; Chessa, Manuela; Solari, Fabio; Bex, Peter J.

2015-01-01

We examine depth perception in images of real scenes with naturalistic variation in pictorial depth cues, simulated dioptric blur and binocular disparity. Light field photographs of natural scenes were taken with a Lytro plenoptic camera that simultaneously captures images at up to 12 focal planes. When accommodation at any given plane was simulated, the corresponding defocus blur at other depth planes was extracted from the stack of focal plane images. Depth information from pictorial cues, relative blur and stereoscopic disparity was separately introduced into the images. In 2AFC tasks, observers were required to indicate which of two patches extracted from these images was farther. Depth discrimination sensitivity was highest when geometric and stereoscopic disparity cues were both present. Blur cues impaired sensitivity by reducing the contrast of geometric information at high spatial frequencies. While simulated generic blur may not assist depth perception, it remains possible that dioptric blur from the optics of an observer’s own eyes may be used to recover depth information on an individual basis. The implications of our findings for virtual reality rendering technology are discussed. PMID:26447793

Autostereoscopic three-dimensional display by combining a single spatial light modulator and a zero-order nulled grating

NASA Astrophysics Data System (ADS)

Su, Yanfeng; Cai, Zhijian; Liu, Quan; Lu, Yifan; Guo, Peiliang; Shi, Lingyan; Wu, Jianhong

2018-04-01

In this paper, an autostereoscopic three-dimensional (3D) display system based on synthetic hologram reconstruction is proposed and implemented. The system uses a single phase-only spatial light modulator to load the synthetic hologram of the left and right stereo images, and the parallax angle between two reconstructed stereo images is enlarged by a grating to meet the split angle requirement of normal stereoscopic vision. To realize the crosstalk-free autostereoscopic 3D display with high light utilization efficiency, the groove parameters of the grating are specifically designed by the rigorous coupled-wave theory for suppressing the zero-order diffraction, and then the zero-order nulled grating is fabricated by the holographic lithography and the ion beam etching. Furthermore, the diffraction efficiency of the fabricated grating is measured under the illumination of a laser beam with a wavelength of 532 nm. Finally, the experimental verification system for the proposed autostereoscopic 3D display is presented. The experimental results prove that the proposed system is able to generate stereoscopic 3D images with good performances.

Measurement of compressed breast thickness by optical stereoscopic photogrammetry

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

Tyson, Albert H.; Mawdsley, Gordon E.; Yaffe, Martin J.

2009-02-15

The determination of volumetric breast density (VBD) from mammograms requires accurate knowledge of the thickness of the compressed breast. In attempting to accurately determine VBD from images obtained on conventional mammography systems, the authors found that the thickness reported by a number of mammography systems in the field varied by as much as 15 mm when compressing the same breast or phantom. In order to evaluate the behavior of mammographic compression systems and to be able to predict the thickness at different locations in the breast on patients, they have developed a method for measuring the local thickness of themore » breast at all points of contact with the compression paddle using optical stereoscopic photogrammetry. On both flat (solid) and compressible phantoms, the measurements were accurate to better than 1 mm with a precision of 0.2 mm. In a pilot study, this method was used to measure thickness on 108 volunteers who were undergoing mammography examination. This measurement tool will allow us to characterize paddle surface deformations, deflections and calibration offsets for mammographic units.« less

Stereoacuity versus fixation disparity as indicators for vergence accuracy under prismatic stress.

PubMed

Kromeier, Miriam; Schmitt, Christina; Bach, Michael; Kommerell, Guntram

2003-01-01

Fixation disparity has been widely used as an indicator for vergence accuracy under prismatic stress. However, the targets used for measuring fixation disparity contain artificial features in that the fusional contours are thinned out. We considered that stereoacuity might be a preferable indicator of vergence accuracy, as stereo targets represent natural viewing conditions. We measured fixation disparity with a computer adaptation of Ogle's test and stereoacuity with the automatic Freiburg Stereoacuity Test. Eight subjects were examined under increasing base-in and base-out prisms. The response of fixation disparity to prismatic stress revealed the curve types described by Ogle and Crone. All eight subjects reached a stereoscopic threshold below 10 arcsec. In seven subjects the stereoscopic threshold increased before double vision occurred. Our data suggest that stereoacuity is suitable to assess the range of binocular vision under prismatic stress. As stereoacuity bears the advantage over fixation disparity in that it can be measured without introducing artificial viewing conditions, we suggest exploring whether stereoacuity under prismatic stress would be more meaningful in the work-up of asthenopic patients than is fixation disparity.

Towards disparity joint upsampling for robust stereoscopic endoscopic scene reconstruction in robotic prostatectomy

NASA Astrophysics Data System (ADS)

Luo, Xiongbiao; McLeod, A. Jonathan; Jayarathne, Uditha L.; Pautler, Stephen E.; Schlacta, Christopher M.; Peters, Terry M.

2016-03-01

Three-dimensional (3-D) scene reconstruction from stereoscopic binocular laparoscopic videos is an effective way to expand the limited surgical field and augment the structure visualization of the organ being operated in minimally invasive surgery. However, currently available reconstruction approaches are limited by image noise, occlusions, textureless and blurred structures. In particular, an endoscope inside the body only has the limited light source resulting in illumination non-uniformities in the visualized field. These limitations unavoidably deteriorate the stereo image quality and hence lead to low-resolution and inaccurate disparity maps, resulting in blurred edge structures in 3-D scene reconstruction. This paper proposes an improved stereo correspondence framework that integrates cost-volume filtering with joint upsampling for robust disparity estimation. Joint bilateral upsampling, joint geodesic upsampling, and tree filtering upsampling were compared to enhance the disparity accuracy. The experimental results demonstrate that joint upsampling provides an effective way to boost the disparity estimation and hence to improve the surgical endoscopic scene 3-D reconstruction. Moreover, the bilateral upsampling generally outperforms the other two upsampling methods in disparity estimation.