Proceedings Volume 8288

Stereoscopic Displays and Applications XXIII

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Proceedings Volume 8288

Stereoscopic Displays and Applications XXIII

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Volume Details

Date Published: 13 March 2012
Contents: 19 Sessions, 93 Papers, 0 Presentations
Conference: IS&T/SPIE Electronic Imaging 2012
Volume Number: 8288

Table of Contents

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Table of Contents

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  • Front Matter: Volume 8288
  • 3D Applications
  • 3D Cameras and Mobile 3D
  • Autostereoscopic Displays: Multi-Layer and Multi-Projector
  • 3D Image Processing and Content Adaptation
  • 3D Developments
  • Perception, Quality, and Comfort
  • Autostereoscopy
  • 3D Image Quality: Crosstalk
  • Stereoscopic 3D Image Quality: Quantifying Perception and Comfort: Joint Session with Conference 8291
  • 3D Games
  • 3D Cinema
  • Stereoscopic Displays
  • Autostereoscopic Displays: Advances and Analysis
  • Interactive Paper Session: Stereoscopic Perception and Quality
  • Interactive Paper Session: 3D Displays
  • Interactive Paper Session: Multiview Image Methods
  • Interactive Paper Session: Stereoscopic Image Methods
  • Interactive Paper Session: Stereoscopic Applications
Front Matter: Volume 8288
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Front Matter: Volume 8288
This PDF file contains the front matter associated with SPIE Proceedings Volume 8288, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing
3D Applications
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Stereoscopic desktop VR system for telemaintenance
Michael Kleiber, Bastian Weltjen, Julia Förster
Tele-cooperation for maintenance is usually supported by synchronous audio but only asynchronous video exchange when only limited bandwidth is available. We present an alternative approach for such a collaborative maintenance task. By utilizing techniques and technologies from Augmented Reality (AR) applications our approach can provide a synchronous shared visual context for the collaborators without a direct video link but through a Desktop VR system. To increase the spatial presence of the remote expert we employ stereoscopic displays. The effectiveness of a stereoscopic 3D system for orientation and localization was evaluated in an abstract experiment. In a more practical experiment the stereoscopic VR system was also evaluated by automobile mechanics. The benefits of stereoscopic Desktop VR systems were shown in both experiments.
3D Cameras and Mobile 3D
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Angle-sensitive pixels: a new paradigm for low-power, low-cost 2D and 3D sensing
Albert Wang, Sheila S. Hemami, Alyosha Molnar
Angle-sensitive pixels are micro-scale devices which capture information about both the intensity and incident angle of the light they see. These pixels acquire a richer description of incident light that conventional intensity-sensitive pixels. We provide a mathematical framework for analyzing the imaging capability of these pixels and demonstrate that they provide a response similar to one component of a 2D Hartley transform in angle, with a distinct frequency and orientation. By using several kinds of different pixels throughout an image sensor, we obtain a full, low-order Hartley transform of local angle, which is mapped to a local, spatial Hartley transform by a conventional camera lens. Based on these principles, we demonstrate a light-field camera using an image sensor composed of angle-sensitive pixels and a conventional camera lens. Single images captured by our camera can be directly used for both computational refocus for enhanced depth of field and depth map generation. The algorithms used for these tasks are simple and take advantage of the transform-based nature of angle-sensitive pixel based image capture.
Polarizing aperture stereoscopic cinema camera
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.
Single lens dual-aperture 3D imaging system: color modeling
Sam Y. Bae, Ronald Korniski, Allen Ream, et al.
In an effort to miniaturize a 3D imaging system, we created two viewpoints in a single objective lens camera. This was accomplished by placing a pair of Complementary Multi-band Bandpass Filters (CMBFs) in the aperture area. Two key characteristics about the CMBFs are that the passbands are staggered so only one viewpoint is opened at a time when a light band matched to that passband is illuminated, and the passbands are positioned throughout the visible spectrum, so each viewpoint can render color by taking RGB spectral images. However, each viewpoint takes a different spectral image from the other viewpoint hence yielding a different color image relative to the other. This color mismatch in the two viewpoints could lead to color rivalry, where the human vision system fails to resolve two different colors. The difference will be closer if the number of passbands in a CMBF increases. (However, the number of passbands is constrained by cost and fabrication technique.) In this paper, simulation predicting the color mismatch is reported.
Unassisted 3D camera calibration
Kalin Atanassov, Vikas Ramachandra, James Nash, et al.
With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.
Auto convergence for stereoscopic 3D cameras
Buyue Zhang, Sreenivas Kothandaraman, Aziz Umit Batur
Viewing comfort is an important concern for 3-D capable consumer electronics such as 3-D cameras and TVs. Consumer generated content is typically viewed at a close distance which makes the vergence-accommodation conflict particularly pronounced, causing discomfort and eye fatigue. In this paper, we present a Stereo Auto Convergence (SAC) algorithm for consumer 3-D cameras that reduces the vergence-accommodation conflict on the 3-D display by adjusting the depth of the scene automatically. Our algorithm processes stereo video in realtime and shifts each stereo frame horizontally by an appropriate amount to converge on the chosen object in that frame. The algorithm starts by estimating disparities between the left and right image pairs using correlations of the vertical projections of the image data. The estimated disparities are then analyzed by the algorithm to select a point of convergence. The current and target disparities of the chosen convergence point determines how much horizontal shift is needed. A disparity safety check is then performed to determine whether or not the maximum and minimum disparity limits would be exceeded after auto convergence. If the limits would be exceeded, further adjustments are made to satisfy the safety limits. Finally, desired convergence is achieved by shifting the left and the right frames accordingly. Our algorithm runs real-time at 30 fps on a TI OMAP4 processor. It is tested using an OMAP4 embedded prototype stereo 3-D camera. It significantly improves 3-D viewing comfort.
Autostereoscopic Displays: Multi-Layer and Multi-Projector
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Beyond parallax barriers: applying formal optimization methods to multilayer automultiscopic displays
Douglas Lanman, Gordon Wetzstein, Matthew Hirsch, et al.
This paper focuses on resolving long-standing limitations of parallax barriers by applying formal optimization methods. We consider two generalizations of conventional parallax barriers. First, we consider general two-layer architectures, supporting high-speed temporal variation with arbitrary opacities on each layer. Second, we consider general multi-layer architectures containing three or more light-attenuating layers. This line of research has led to two new attenuation-based displays. The High-Rank 3D (HR3D) display contains a stacked pair of LCD panels; rather than using heuristically-defined parallax barriers, both layers are jointly-optimized using low-rank light field factorization, resulting in increased brightness, refresh rate, and battery life for mobile applications. The Layered 3D display extends this approach to multi-layered displays composed of compact volumes of light-attenuating material. Such volumetric attenuators recreate a 4D light field when illuminated by a uniform backlight. We further introduce Polarization Fields as an optically-efficient and computationally efficient extension of Layered 3D to multi-layer LCDs. Together, these projects reveal new generalizations to parallax barrier concepts, enabled by the application of formal optimization methods to multi-layer attenuation-based designs in a manner that uniquely leverages the compressive nature of 3D scenes for display applications.
3D image quality of 200-inch glasses-free 3D display system
M. Kawakita, S. Iwasawa, M. Sakai, et al.
We have proposed a glasses-free three-dimensional (3D) display for displaying 3D images on a large screen using multi-projectors and an optical screen consisting of a special diffuser film with a large condenser lens. To achieve high presence communication with natural large-screen 3D images, we numerically analyze the factors responsible for degrading image quality to increase the image size. A major factor that determines the 3D image quality is the arrangement of component units, such as the projector array and condenser lens, as well as the diffuser film characteristics. We design and fabricate a prototype 200-inch glasses-free 3D display system on the basis of the numerical results. We select a suitable diffuser film, and we combine it with an optimally designed condenser lens. We use 57 high-definition projector units to obtain viewing angles of 13.5°. The prototype system can display glasses-free 3D images of a life-size car using natural parallax images.
Implementation and analysis of an autostereoscopic display using multiple liquid crystal layers
Hironobu Gotoda
Multilayer displays are constructed by stacking multiple liquid crystal panels along with a pair of polarizers and a light source. Previous theoretical analyses have shown that such a display could exhibit the light field of a 3D scene if the panels in the display are properly controlled. In this study, we present an implementation of a monochromatic multilayer display using IPS-LCD panels, and report that a reasonable approximation of the light field is actually observed from the display. A major obstacle to constructing a multilayer display is the complexity of optical properties of LCD panels. Since an accurate analytic representation of panels' behavior is difficult to obtain, we have developed an approximate model specific to IPS-LCD cells, using which our implementation is built. We then evaluate the quality of the light field observed from the prototype implementation by examining the images photographed at several camera positions. The results show geometrically correct views are observable from the display within the viewing angle of 30 degrees.
360-degree three-dimensional table-screen display using small array of high-speed projectors
Shigeki Uchida, Yasuhiro Takaki
A new 360-degree three-dimensional table-screen display is proposed, which combines the previously proposed highspeed projector and multi-projector systems. The proposed system consists of a small number of high-speed projectors and a rotating screen. Because each high-speed projector is located outside the rotating axis of the screen, multiple projectors can be aligned above or below the rotating screen. The lens shift technique is used to superimpose multiple images generated by all projectors on the rotating screen. The screen has an off-axis lens function such that the rotation of the screen generates numerous viewpoints on a circle around the rotating screen. Each projector generates numerous viewpoints on a different circle. The use of multiple projectors enables the increase in the number of colors, the reduction of the rotation speed of the screen, and the increase in the number of viewpoints. An experimental system employing two digital micro-mirror device (DMD) projectors and white LEDs was demonstrated. The rotating speed of the screen was 1,666 rpm in order to generate a 3D image with a frame rate of 28 Hz. Each projector generated 800 viewpoints on a different circle with a diameter 800 mm. The diameter of the screen was 300 mm. The 3D resolution was 768 × 768.
3D Image Processing and Content Adaptation
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Focus mismatch detection in stereoscopic content
Frédéric Devernay, Sergi Pujades, Vijay Ch.A.V.
Live-action stereoscopic content production requires a stereo rig with two cameras precisely matched and aligned. While most deviations from this perfect setup can be corrected either live or in post-production, a difference in the focus distance or focus range between the two cameras will lead to unrecoverable degradations of the stereoscopic footage. In this paper we detect focus mismatch between views of a stereoscopic pair in four steps. First, we compute a dense disparity map. Then, we use a measure to compare focus in both images. After this, we use robust statistics to find which images zones have a different focus. Finally, to give useful feedback, we show the results on the original images and give hints on how to solve the focus mismatch.
Automatic 2D-to-3D image conversion using 3D examples from the internet
J. Konrad, G. Brown, M. Wang, et al.
The availability of 3D hardware has so far outpaced the production of 3D content. Although to date many methods have been proposed to convert 2D images to 3D stereopairs, the most successful ones involve human operators and, therefore, are time-consuming and costly, while the fully-automatic ones have not yet achieved the same level of quality. This subpar performance is due to the fact that automatic methods usually rely on assumptions about the captured 3D scene that are often violated in practice. In this paper, we explore a radically different approach inspired by our work on saliency detection in images. Instead of relying on a deterministic scene model for the input 2D image, we propose to "learn" the model from a large dictionary of stereopairs, such as YouTube 3D. Our new approach is built upon a key observation and an assumption. The key observation is that among millions of stereopairs available on-line, there likely exist many stereopairs whose 3D content matches that of the 2D input (query). We assume that two stereopairs whose left images are photometrically similar are likely to have similar disparity fields. Our approach first finds a number of on-line stereopairs whose left image is a close photometric match to the 2D query and then extracts depth information from these stereopairs. Since disparities for the selected stereopairs differ due to differences in underlying image content, level of noise, distortions, etc., we combine them by using the median. We apply the resulting median disparity field to the 2D query to obtain the corresponding right image, while handling occlusions and newly-exposed areas in the usual way. We have applied our method in two scenarios. First, we used YouTube 3D videos in search of the most similar frames. Then, we repeated the experiments on a small, but carefully-selected, dictionary of stereopairs closely matching the query. This, to a degree, emulates the results one would expect from the use of an extremely large 3D repository. While far from perfect, the presented results demonstrate that on-line repositories of 3D content can be used for effective 2D-to-3D image conversion. With the continuously increasing amount of 3D data on-line and with the rapidly growing computing power in the cloud, the proposed framework seems a promising alternative to operator-assisted 2D-to-3D conversion.
3D cinema to 3DTV content adaptation
L. Yasakethu, L. Blondé, D. Doyen, et al.
3D cinema and 3DTV have grown in popularity in recent years. Filmmakers have a significant opportunity in front of them given the recent success of 3D films. In this paper we investigate whether this opportunity could be extended to the home in a meaningful way. "3D" perceived from viewing stereoscopic content depends on the viewing geometry. This implies that the stereoscopic-3D content should be captured for a specific viewing geometry in order to provide a satisfactory 3D experience. However, although it would be possible, it is clearly not viable, to produce and transmit multiple streams of the same content for different screen sizes. In this study to solve the above problem, we analyze the performance of six different disparity-based transformation techniques, which could be used for cinema-to-3DTV content conversion. Subjective tests are performed to evaluate the effectiveness of the algorithms in terms of depth effect, visual comfort and overall 3D quality. The resultant 3DTV experience is also compared to that of cinema. We show that by applying the proper transformation technique on the content originally captured for cinema, it is possible to enhance the 3DTV experience. The selection of the appropriate transformation is highly dependent on the content characteristics.
Video retargeting for stereoscopic content under 3D viewing constraints
C. Chamaret, G. Boisson, C. Chevance
The imminent deployment of new devices such as TV, tablet, smart phone supporting stereoscopic display creates a need for retargeting the content. New devices bring their own aspect ratio and potential small screen size. Aspect ratio conversion becomes mandatory and an automatic solution will be of high value especially if it maximizes the visual comfort. Some issues inherent to 3D domain are considered in this paper: no vertical disparity, no object having negative disparity (outward perception) on the border of the cropping window. A visual attention model is applied on each view and provides saliency maps with most attractive pixels. Dedicated 3D retargeting correlates the 2D attention maps for each view as well as additional computed information to ensure the best cropping window. Specific constraints induced by 3D experience influence the retargeted window through the map computation presenting objects that should not be cropped. The comparison with original content of 2:35 ratio having black stripes provide limited 3D experience on TV screen, while the automatic cropping and exploitation of full screen show more immersive experience. The proposed system is fully automatic, ensures a good final quality without missing fundamental parts for the global understanding of the scene. Eye-tracking data recorded on stereoscopic content have been confronted to retargeted window in order to ensure that the most attractive areas are inside the final video.
3D Developments
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Stereoscopic-3D display design: a new paradigm with Intel Adaptive Stable Image Technology [IA-SIT]
Stereoscopic-3D (S3D) proliferation on personal computers (PC) is mired by several technical and business challenges: a) viewing discomfort due to cross-talk amongst stereo images; b) high system cost; and c) restricted content availability. Users expect S3D visual quality to be better than, or at least equal to, what they are used to enjoying on 2D in terms of resolution, pixel density, color, and interactivity. Intel Adaptive Stable Image Technology (IA-SIT) is a foundational technology, successfully developed to resolve S3D system design challenges and deliver high quality 3D visualization at PC price points. Optimizations in display driver, panel timing firmware, backlight hardware, eyewear optical stack, and synch mechanism combined can help accomplish this goal. Agnostic to refresh rate, IA-SIT will scale with shrinking of display transistors and improvements in liquid crystal and LED materials. Industry could profusely benefit from the following calls to action:- 1) Adopt 'IA-SIT S3D Mode' in panel specs (via VESA) to help panel makers monetize S3D; 2) Adopt 'IA-SIT Eyewear Universal Optical Stack' and algorithm (via CEA) to help PC peripheral makers develop stylish glasses; 3) Adopt 'IA-SIT Real Time Profile' for sub-100uS latency control (via BT Sig) to extend BT into S3D; and 4) Adopt 'IA-SIT Architecture' for Monitors and TVs to monetize via PC attach.
A real-time misalignment correction algorithm for stereoscopic 3D cameras
Ibrahim E. Pekkucuksen, Aziz Umit Batur, Buyue Zhang
Camera calibration is an important problem for stereo 3-D cameras since the misalignment between the two views can lead to vertical disparities that significantly degrade 3-D viewing quality. Offline calibration during manufacturing is not always an option especially for mass produced cameras due to cost. In addition, even if one-time calibration is performed during manufacturing, its accuracy cannot be maintained indefinitely because environmental factors can lead to changes in camera hardware. In this paper, we propose a real-time stereo calibration solution that runs inside a consumer camera and continuously estimates and corrects for the misalignment between the stereo cameras. Our algorithm works by processing images of natural scenes and does not require the use of special calibration charts. The algorithm first estimates the disparity in horizontal and vertical directions between the corresponding blocks from stereo images. Then, this initial estimate is refined with two dimensional search using smaller sub-blocks. The displacement data and block coordinates are fed to a modified affine transformation model and outliers are discarded to keep the modeling error low. Finally, the estimated affine parameters are split by half and misalignment correction is applied to each view accordingly. The proposed algorithm significantly reduces the misalignment between stereo frames and enables a more comfortable 3-D viewing experience.
Full color stereoscopy with little flicker at low refresh rate by time-division multiplexing anaglyph
Hideki Kakeya, Hiroaki Kodaira
In the present paper we propose a time-division multiplexing anaglyph method to realize full color stereoscopy with little flicker at the low refresh rate of 60 Hz, which is compatible with the conventional 2D displays. Because of the low refresh rate, applying time-division multiplexing method using shutter glasses to conventional displays results in severe flicker. To overcome this problem, we propose a time-division multiplexing anaglyph method, where the green components of right-eye image is shown to the right eye and the red and blue component of left-eye image is shown to the left eye at odd frames, while the red and blue component of right-eye image is shown to the right eye and the green components of left-eye image is shown to the left eye at even frames. We carry out an experiment to let the subjects see time-division multiplexing anaglyph images and the result shows that flicker can be reduced to an acceptable level by the proposed method. The proposed method can also be applied to widening the viewing angle of time-division multiplexing integral imaging.
Supervised disparity estimation
Patrick Vandewalle, Chris Varekamp
We introduce supervised disparity estimation in which an operator can steer the disparity estimation process. Instead of correcting errors, we view the estimation process as a constrained process where the constraints are indicated by the user in the form of control points, scribbles and contours. Control points are used to obtain accurate disparity estimates that can be fully controlled by the operator. Scribbles are used to force regions to have a smooth disparity, while contours create a disparity discontinuity in places where diffusion or energy minimization fail. Control points, scribbles and contours are propagated through the video sequence to create temporally stable results.
Analysis of brain activity and response during monoscopic and stereoscopic visualization
Enrico Calore, Raffaella Folgieri, Davide Gadia, et al.
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.
Perception, Quality, and Comfort
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Motion in depth constancy in stereoscopic displays
Sidrah R. Laldin, Laurie M. Wilcox, Carly Hylton, et al.
In a stereoscopic 3D scene, non-linear mapping between real space and disparity could produce distortions when camera geometry differs from natural stereoscopic geometry. When the viewing distance and zero screen parallax setting are held constant and interaxial separation is varied, there is an asymmetric distortion in the mapping of stereoscopic to real space. If an object traverses this space at constant velocity, one might anticipate distortion of the perceived velocity. To determine if the predicted distortions are in fact perceived, we assessed perceived acceleration and deceleration using an animation of a ball moving in depth through a simulated environment, viewed stereoscopically. The method of limits was used to measure transition points between perceived acceleration and deceleration as a function of interaxial and context (textured vs. non-textured background). Based on binocular geometry, we predicted that the transition points would shift toward deceleration for small and towards acceleration for large interaxial separations. However, the average transition values were not influenced by interaxial separation. These data suggest that observers are able to discount distortions of stereoscopic space in interpreting the object motion. These results have important implications for the rendering or capture of effective stereoscopic 3D content.
Evaluation of quality of experience in interactive 3D visualization: methodology and results
Sylvain Tourancheau, Mårten Sjöström, Roger Olsson, et al.
Human factors are of high importance in 3D visualization, but subjective evaluation of 3D displays is not easy because of a high variability among users. This study aimed to evaluate and compare two different 3D visualization systems (a market stereoscopic display, and a state-of-the-art multi-view display) in terms of user performance and quality of experience (QoE), in the context of interactive visualization. An adapted methodology has been designed in order to focus on 3D differences and to reduce the influence of all other factors. Thirty-six subjects took part in an experiment during which they were asked to judge the quality of their experience, according to specific features. Results showed that a scene understanding and precision was significantly better on the multi-view display. Concerning the quality of experience, visual comfort was judged significantly better on the multi-view display and visual fatigue was reported by 52% of the subjects on the stereoscopic display. This study has permitted to identify some factors influencing QoE such as prior experience and stereopsis threshold.
Disparity profiles in 3DV applications: overcoming the issue of heterogeneous viewing conditions in stereoscopic delivery
Guillaume Boisson, Christel Chamaret
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.
Investigation of object thickness for visual discomfort prediction in stereoscopic images
Visual discomfort assessment metric is of importance in the creation and viewing of stereoscopic 3D contents. This paper investigates the importance of considering object thickness as well as disparity magnitude to predict visual discomfort. Throughout the paper, we introduce the overall process to predict visual discomfort by analyzing the thickness of objects and their disparity magnitude in an image. Using natural stereoscopic images, we evaluate the contribution of object thickness to the prediction performance of visual discomfort. Experimental results demonstrate that the combined use of disparity magnitude and object thickness substantially improves the prediction performance of visual discomfort.
Autostereoscopy
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History of autostereoscopic cinema
This paper covers the history of autostereoscopic cinema, from the beginnings of autostereoscopy in the 1800s, the development of motion capability and it's subsequent evolution to present techniques. Public viewings of autostereoscopic movies have occurred on a semi-ongoing basis since the early 1940s. In Moscow and other cities, theaters were constructed called stereokinos, for showing autostereoscopic films, with specially positioned seating for proper viewing. The Cyclostéréoscope was an autostereoscopic cinema system invented by François Savoye in France. It was based around a drum made of metal bars that revolve around a screen. For several years in the 1940s and 1950s, it was open to the public in Paris. Any film made in a dual film format could be shown. Besides dedicated theaters in Russia and France, exhibits of content have occurred outside devoted theaters. The paper focuses on the history of autostereoscopic technology developed for entertainment, public viewing of content, the individuals involved and the content itself.
Full optical characterization of autostereoscopic 3D displays using local viewing angle and imaging measurements
Pierre Boher, Thierry Leroux, Thibault Bignon, et al.
Two commercial auto-stereoscopic 3D displays are characterized a using Fourier optics viewing angle system and an imaging video-luminance-meter. One display has a fixed emissive configuration and the other adapts its emission to the observer position using head tracking. For a fixed emissive condition, three viewing angle measurements are performed at three positions (center, right and left). Qualified monocular and binocular viewing spaces in front of the display are deduced as well as the best working distance. The imaging system is then positioned at this working distance and crosstalk homogeneity on the entire surface of the display is measured. We show that the crosstalk is generally not optimized on all the surface of the display. Display aspect simulation using viewing angle measurements allows understanding better the origin of those crosstalk variations. Local imperfections like scratches and marks generally increase drastically the crosstalk, demonstrating that cleanliness requirements for this type of display are quite critical.
Analysis on monocular accommodation in horizontal-parallax-only super-multiview display
Accommodation response of super-multiview display device, which is implemented to provide horizontal-only parallax, has been investigated. Because of astigmatic characteristic of such display, the focal points of horizontal and vertical directions differ in longitudinal direction. Assuming that the accommodation response to the astigmatic image follows the distance where the average of bandwidths in vertical and horizontal direction becomes the maximum, numerical calculations presented that the accommodation restrictedly follows three-dimensional point near the display panel. To verify the consequence obtained by numerical calculations, experiments has been performed using keratometer to measure the accommodation under the situation similar to horizontal-only super-multiview display. The images focused by a cylindrical lens have been provided as stimuli to avoid argues related to the resolution of pixel pitch of display panel. The measured results show that the accommodation response restrictedly follows astigmatic image as expected by numerical calculations, however the quantitative investigation is still needed.
A novel time-multiplexed autostereoscopic multiview full resolution 3D display
Many people believe that in the future, autostereoscopic 3D displays will become a mainstream display type. Achievement of higher quality 3D images requires both higher panel resolution and more viewing zones. Consequently, the transmission bandwidth of the 3D display systems involves enormous amounts of data transfer. We propose and experimentally demonstrate a novel time-multiplexed autostereoscopic multi-view full resolution 3D display based on the lenticular lens array in association with the control of the active dynamic LED backlight. The lenticular lenses of the lens array optical system receive the light and deflect the light into each viewing zone in a time sequence. The crosstalk under different observation scanning angles is showed, including the cases of 4-views field scanning. The crosstalk of any view zones is about 5% respectively; the results are better than other 3D type.
3D Image Quality: Crosstalk
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Crosstalk reduces the amount of depth seen in 3D images of natural scenes
Inna Tsirlin, Robert S. Allison, Laurie M. Wilcox
Crosstalk remains an important determinant of stereoscopic 3D (S3D) image quality. Defined as the leakage of one eye's image into the image of the other eye it affects all commercially available stereoscopic viewing systems. Previously we have shown that crosstalk affects perceived depth magnitude in S3D displays. We found that perceived depth between two lines separated in depth decreased as crosstalk increased. The experiments described here extend our previous work to complex images of natural scenes. We controlled crosstalk levels by simulating them in images presented on a zero-crosstalk mirror stereoscope display. The observers were asked to estimate the amount of stereoscopic depth between pairs of objects in stereo-photographs of cluttered rooms. Data show that as crosstalk increased perceived depth decreased; an effect found at all disparities. Similarly to our previous experiments a significant decrease in perceived depth was observed with as little as 2-4% crosstalk. Taken together these results demonstrate that our previous findings generalize to natural scenes and show that crosstalk reduces perceived depth magnitude even in natural scenes with pictorial depth cues.
Method and simulation to study 3D crosstalk perception
Dar'ya Khaustova, Laurent Blondé, Quan Huynh-Thu, et al.
To various degrees, all modern 3DTV displays suffer from crosstalk, which can lead to a decrease of both visual quality and visual comfort, and also affect perception of depth. In the absence of a perfect 3D display technology, crosstalk has to be taken into account when studying perception of 3D stereoscopic content. In order to improve 3D presentation systems and understand how to efficiently eliminate crosstalk, it is necessary to understand its impact on human perception. In this paper, we present a practical method to study the perception of crosstalk. The approach consists of four steps: (1) physical measurements of a 3DTV, (2) building of a crosstalk surface based on those measurements and representing specifically the behavior of that 3TV, (3) manipulation of the crosstalk function and application on reference images to produce test images degraded by crosstalk in various ways, and (4) psychophysical tests. Our approach allows both a realistic representation of the behavior of a 3DTV and the easy manipulation of its resulting crosstalk in order to conduct psycho-visual experiments. Our approach can be used in all studies requiring the understanding of how crosstalk affects perception of stereoscopic content and how it can be corrected efficiently.
Reproducibility of crosstalk measurements on active glasses 3D LCD displays based on temporal characterization
Sylvain Tourancheau, Kun Wang, Jarosław Bułat, et al.
Crosstalk is one of the main display-related perceptual factors degrading image quality and causing visual discomfort on 3D-displays. It causes visual artifacts such as ghosting effects, blurring, and lack of color fidelity which are considerably annoying and can lead to difficulties to fuse stereoscopic images. On stereoscopic LCD with shutter-glasses, crosstalk is mainly due to dynamic temporal aspects: imprecise target luminance (highly dependent on the combination of left-view and right-view pixel color values in disparity regions) and synchronization issues between shutter-glasses and LCD. These different factors influence largely the reproducibility of crosstalk measurements across laboratories and need to be evaluated in several different locations involving similar and differing conditions. In this paper we propose a fast and reproducible measurement procedure for crosstalk based on high-frequency temporal measurements of both display and shutter responses. It permits to fully characterize crosstalk for any right/left color combination and at any spatial position on the screen. Such a reliable objective crosstalk measurement method at several spatial positions is considered a mandatory prerequisite for evaluating the perceptual influence of crosstalk in further subjective studies.
Crosstalk and brightness in projection-based multiview systems
Roland Blach, Achim Pross, Alexander Kulik, et al.
Immersive visualization environments have generally been built on single user stereoscopic displays. We have extended these systems to multi-view systems that provide perspectively correct stereoscopic image pairs for up to six users. As a result, groups of users can explore a shared 3D virtual environment from all perspectives and discuss it using barehanded gestures. From all displayed images, each user should perceive only one dedicated image per eye. All additional views must be filtered. Consequently, the noise level for each user increases with the number of displayed views. Keeping the image crosstalk under the threshold of human perception is a necessity for this type of visualization system. To separate the images we have used a hybrid approach which combines active shuttering and passive polarization filtering. In projection-based view systems brightness and crosstalk are one of the major issues which have to be handled as the noise increases and the signal brightness decreases with the increase of views. To evaluate different technical approaches for optimization and also to compare these systems with existing single user 3D systems, we have extended the crosstalk measurement approach by Weissman and Woods to our projection-based specific multi-view case where the eye separation is carried out with polarization filters and the user separation with time sequential shutter elements. Our contribution is a method for defining and measuring crosstalk for projection-based multi-view systems.
How much crosstalk can be allowed in a stereoscopic system at various grey levels?
Sergey Shestak, Daesik Kim, Yongie Kim
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.
Stereoscopic 3D Image Quality: Quantifying Perception and Comfort: Joint Session with Conference 8291
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Visual discomfort and the temporal properties of the vergence-accommodation conflict
The vergence-accommodation conflict associated with viewing stereoscopic 3D (S3D) content can cause visual discomfort. Previous studies of vergence and accommodation have shown that the coupling between the two responses is driven by a fast, phasic component. We investigated how the temporal properties of vergence-accommodation conflicts affect discomfort. Using a unique volumetric display, we manipulated the stimulus to vergence and the stimulus to accommodation independently. There were two experimental conditions: 1) natural viewing in which the stimulus to vergence was perfectly correlated with the stimulus to accommodation; and 2) conflict viewing in which the stimulus to vergence varied while the stimulus to accommodation remained constant (thereby mimicking S3D viewing). The stimulus to vergence (and accommodation in natural viewing) varied at one of three temporal frequencies in those conditions. The magnitude of the conflict was the same for all three frequencies. The young adult subjects reported more visual discomfort when vergence changes were faster, particularly in the conflict condition. Thus, the temporal properties of the vergence-accommodation conflict in S3D media affect visual discomfort. The results can help content creators minimize discomfort by making conflict changes sufficiently slow.
Visual fatigue versus eye-movements
Cyril Vienne, Laurent Blondé, Didier Doyen
Observing 3D content on a cinema or TV screen potentially generates fatigue. In psychovisual research, experience of visual symptoms following the observation of stereo-content is usually assessed thanks to questionnaires and subjective reports. We attempted to explore the occurrence of visual fatigue using more objective methods, namely by using binocular eye-tracking and psychophysics. A main objective was to study the emergence of visual fatigue in relation with eye-movement knowing the stimulation of the oculomotor system and its response. We designed an experiment in which participants were asked to perform a repeated vergence effort task, just followed by, and interlaced with, a 3D space perception task. Participants' eye movements were recorded during the whole session using an eye-tracking system. The analysis revealed that the perception of 3D shapes was gradually affected by the intensity of the vergence effort task. The effect on stereo-estimation was actually due to visual fatigue. 3D objects and scenes are perceived flatter. Results on the subjective reports of SSQ revealed that oculomotor factors were predominant in the visual symptoms. In addition, some effects and correlations on the micro-saccadic rate were obtained. This work offers a perspective to characterize objectively visual fatigue when watching stereoscopic 3D content.
Visual comfort: stereoscopic objects moving in the horizontal and mid-sagittal planes
Two experiments were conducted to examine the visual comfort of stereoscopic images. The test video sequences consisted of moving meteorite-like objects against a blue sky background. In the first experiment, a panel of viewers rated stereoscopic sequences in which the objects moved back and forth in depth. The velocity of movement, disparity (depth) range, and disparity type (i.e., depth position with respect to the screen plane: front, behind, or front/behind) of the objects varied across sequences. In the second experiment, the same viewers rated stereoscopic test sequences in which the target objects moved horizontally across the screen. Also in this case, the velocity, disparity magnitude, and disparity type of the objects varied across sequences. For motion in the depth direction, the results indicate that visual comfort is significantly influenced by the velocity, disparity range, and disparity type of the moving objects. We also found significant interactions between velocity and disparity type and between disparity type and disparity range. For motion across the screen in the horizontal plane, ratings of visual comfort depended on velocity and disparity magnitude. The results also indicate a significant interaction between velocity and disparity. In general, the overall results confirm that changes in disparity of stereoscopic images over time are a significant contributor to visual discomfort. Interestingly, the detrimental effect of object velocity on visual comfort are manifested even when the changes are confined within the generally accepted visual comfort zone of less than 60 arc minutes of horizontal disparity.
Visual discomfort with stereo 3D displays when the head is not upright
David Kane, Robert T. Held, Martin S. Banks
Properly constructed stereoscopic images are aligned vertically on the display screen, so on-screen binocular disparities are strictly horizontal. If the viewer's inter-ocular axis is also horizontal, he/she makes horizontal vergence eye movements to fuse the stereoscopic image. However, if the viewer's head is rolled to the side, the onscreen disparities now have horizontal and vertical components at the eyes. Thus, the viewer must make horizontal and vertical vergence movements to binocularly fuse the two images. Vertical vergence movements occur naturally, but they are usually quite small. Much larger movements are required when viewing stereoscopic images with the head rotated to the side. We asked whether the vertical vergence eye movements required to fuse stereoscopic images when the head is rolled cause visual discomfort. We also asked whether the ability to see stereoscopic depth is compromised with head roll. To answer these questions, we conducted behavioral experiments in which we simulated head roll by rotating the stereo display clockwise or counter-clockwise while the viewer's head remained upright relative to gravity. While viewing the stimulus, subjects performed a psychophysical task. Visual discomfort increased significantly with the amount of stimulus roll and with the magnitude of on-screen horizontal disparity. The ability to perceive stereoscopic depth also declined with increasing roll and on-screen disparity. The magnitude of both effects was proportional to the magnitude of the induced vertical disparity. We conclude that head roll is a significant cause of viewer discomfort and that it also adversely affects the perception of depth from stereoscopic displays.
3D Games
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Case study: the introduction of stereoscopic games on the Sony PlayStation 3
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.
Stereoscopic 3D video games and their effects on engagement
Andrew Hogue, Bill Kapralos, Chris Zerebecki, et al.
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.
Stereoscopic display in a slot machine
M. Laakso
This paper reports the results of a user trial with a slot machine equipped with a stereoscopic display. The main research question was to find out what kind of added value does stereoscopic 3D (S-3D) bring to slot games? After a thorough literature survey, a novel gaming platform was designed and implemented. Existing multi-game slot machine "Nova" was converted to "3DNova" by replacing the monitor with an S-3D display and converting six original games to S-3D format. To evaluate the system, several 3DNova machines were put available for players for four months. Both qualitative and quantitative analysis was carried out from statistical values, questionnaires and observations. According to the results, people find the S-3D concept interesting but the technology is not optimal yet. Young adults and adults were fascinated by the system, older people were more cautious. Especially the need to wear stereoscopic glasses provide a challenge; ultimate system would probably use autostereoscopic technology. Also the games should be designed to utilize its full power. The main contributions of this paper are lessons learned from creating an S-3D slot machine platform and novel information about human factors related to stereoscopic slot machine gaming.
3D Cinema
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New approach on calculating multiview 3D crosstalk for autostereoscopic displays
Sung-Min Jung, Kyeong-Jin Lee, Ji-Na Kang, et al.
In this study, we suggest a new concept of 3D crosstalk for auto-stereoscopic displays and obtain 3D crosstalk values of several multi-view systems based on the suggested definition. First, we measure the angular dependencies of the luminance for auto-stereoscopic displays under various test patterns corresponding to each view of a multi-view system and then calculate the 3D crosstalk based on our new definition with respect to the measured luminance profiles. Our new approach gives just a single 3D crosstalk value for single device without any ambiguity and shows similar order of values to the conventional stereoscopic displays. These results are compared with the conventional 3D crosstalk values of selected auto-stereoscopic displays such as 4-view and 9-view systems. From the result, we believe that this new approach is very useful for controlling 3D crosstalk values of the 3D displays manufacturing and benchmarking of the 3D performances among the various auto-stereoscopic displays.
YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters
Jonas Schild, Sven Seele, Maic Masuch
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.
Thinking in z-space: flatness and spatial narrativity
Ray Zone
Now that digital technology has accessed the Z-space in cinema, narrative artistry is at a loss. Motion picture professionals no longer can readily resort to familiar tools. A new language and new linguistics for Z-axis storytelling are necessary. After first examining the roots of monocular thinking in painting, prior modes of visual narrative in twodimensional cinema obviating true binocular stereopsis can be explored, particularly montage, camera motion and depth of field, with historic examples. Special attention is paid to the manner in which monocular cues for depth have been exploited to infer depth on a planar screen. Both the artistic potential and visual limitations of actual stereoscopic depth as a filmmaking language are interrogated. After an examination of the historic basis of monocular thinking in visual culture, a context for artistic exploration of the use of the z-axis as a heightened means of creating dramatic and emotional impact upon the viewer is illustrated.
Stereoscopic Displays
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Investigating the cross-compatibility of IR-controlled active shutter glasses
Andrew J. Woods, Jesse Helliwell
Active Shutter Glasses (also known as Liquid Crystal Shutter (LCS) 3D glasses or just Shutter Glasses) are a commonly used selection device used to view stereoscopic 3D content on time-sequential stereoscopic displays. Regrettably most of the IR (infrared) controlled active shutter glasses released to date by various manufacturers have used a variety of different IR communication protocols which means that active shutter glasses from one manufacturer are generally not cross-compatible with another manufacturer's emitter. The reason for the lack of cross-compatibility between different makes of active shutter glasses mostly relates to differences between the actual IR communication protocol used for each brand of glasses. We have characterized eleven different 3D sync IR communications protocols in order to understand the possibility of cross-compatibility between different brands of glasses. This paper contains a summary of the eleven different 3D sync IR protocols as used by a selection of emitters and glasses. The paper provides a discussion of the similarities and differences between the different protocols, the limitations for creating a common 3D sync protocol, and the possibility of driving multiple brands of glasses at the same time.
New high efficiency interference filter characteristics for stereoscopic imaging
The goal of this work was the optimization of brightness and colors performance of the interference filter system for 3D projection. Special emphasis was on avoiding, or at least reducing, the need for color correction, which was one of reasons for low luminous efficiencies in the past. On the base of datasets for various projectors (DLP, LCoS, LCD) and lamps (UHP and Xenon), the optimization for a high efficiency stereoscopic interference filter system was carried out. Focus of our study was on three by four (3-4) filter system. We also examined filter designs with higher numbers of transmission bands up to seven per filter. The results show that the 3-4 band filters design exhibits the highest efficiency of all inherently color balanced filter systems because of a minimum number of gaps between adjacent transmission bands. Results also revealed that Xenon lamp based systems and UHP lamp based systems have different optimum filters. However, differences are such small that it becomes possible to cover both systems by a unitary type of 3D glasses lenses.
Real-world stereoscopic performance in multiple-focal-plane displays: How far apart should the image planes be?
Conventional stereoscopic displays present conflicting stimuli to vergence and accommodation, causing fatigue, discomfort, and poor stereo depth perception. One promising solution is 'depth filtering', in which continuous variations in focal distance are simulated by distributing image intensity across multiple focal planes. The required image-plane spacing is a critical parameter, because there are constraints on the total number that can be used. Depth-filtered images have been shown to support continuous and reasonably accurate accommodation responses with 1.1 dioptre (D) image-plane spacings. However, retinal contrast is increasingly attenuated with increasing image-plane separation. Thus, while such stimuli may eliminate the vergence-accommodation conflict, they may also unacceptably degrade stereoscopic depth perception. Here we measured stereoacuity, and the time needed for stereoscopic fusion, for real targets and depth-filtered approximations to the same stimuli (image-plane spacings of 0.6, 0.9 and 1.2 D). Stereo fusion time was reasonably consistent across conditions. Stereoacuity for depth-filtered stimuli was only slightly poorer than for real targets with 0.6 D image-plane separation, but deteriorated rapidly thereafter. Our results suggest that stereoscopic depth perception, not accommodation and vergence responses, is the limiting factor in determining acceptable image-plane spacing for depth-filtered images. We suggest that image-plane spacing should ideally not exceed ~0.6 D.
A compact eyetracked optical see-through head-mounted display
Hong Hua, Chunyu Gao
An eye-tracked head-mounted display (ET-HMD) system is able to display virtual images as a classical HMD does, while additionally tracking the gaze direction of the user. There is ample evidence that a fully-integrated ETHMD system offers multi-fold benefits, not only to fundamental scientific research but also to emerging applications of such technology. For instance eyetracking capability in HMDs adds a very valuable tool and objective metric for scientists to quantitatively assess user interaction with 3D environments and investigate the effectiveness of various 3D visualization technologies for various specific tasks including training, education, and augmented cognition tasks. In this paper, we present an innovative optical approach to the design of an optical see-through ET-HMD system based on freeform optical technology and an innovative optical scheme that uniquely combines the display optics with the eye imaging optics. A preliminary design of the described ET-HMD system will be presented.
Optimization of a multiview system based on pulsed LED-LCD projectors
Achim Pross, Roland Blach, Matthias Bues, et al.
In recent years, huge advancements in stereoscopic displays and 3D projection technologies have been accomplished, mainly driven by the rapidly increasing dissemination of 3D technologies at cinemas and in consumer products. Virtual Reality systems built from these products, enhanced by head tracking are able to produce a perspective-correct view, but for a single user only. Other viewers share the same image from a different position and thus see a more or less distorted image, while actually a perspective-correct stereoscopic views for multiple, individually tracked users on a would be necessary. We present multi-view stereo display based on pulsed LED light sources of a set of multiple LCD projectors which is strongly optimized towards high brightness and minimum crosstalk. Pulsed LED projectors allow high frequency switching between the displayed images, almost eliminating a major source of crosstalk between the individual views. We evaluated the power consumption, projection brightness and crosstalk of our multi-view system and present a solution which alleviates the inherent problems of shutter-based multi-view systems, which are low energy efficiency, brightness degradation due to the projector shutter, and relatively high crosstalk, which, moreover, increases with the number of views.
Autostereoscopic Displays: Advances and Analysis
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Floating three-dimensional display viewable from 360 degrees
Daisuke Miyazaki, Nobuhiro Akasaka, Kenta Okoda, et al.
The aim of this research is to develop a full-parallax auto-stereoscopic display system, which can generate a floating three-dimensional (3-D) image viewable from a surrounding area. A 3-D display method based on the combination of integral imaging, 360-degree scanning with a rotating mirror, and imaging in the air with a concave mirror is proposed. A scanning system is composed of a hemisphere concave mirror and a mirror scanner, which is located around the center of the concave mirror. By putting an image generated by an integral imaging system into the scanning system, a floating stereoscopic image can be formed around the center of the concave mirror. When the mirror scanner rotates and the image on the integral imaging system is switched in accordance with mirror angle, each directional image can be observed from each viewing angle. The feasibility of the proposed method was examined by preliminary experiments. The abilities of generation of a floating full-parallax image and a floating auto-stereoscopic image with 360-degree viewing angle are demonstrated.
A method to introduce accommodation cues into 3D integral imaging system using Fresnel holograms
J.-S. Chen, N. Collings, D. P. Chu
Conventional 3D Integral imaging suffers from limited image depth range due to the fixed distance between the display panel and the lens array, while digital Fresnel holography suffers from a narrow viewing angle due to the lack of a high resolution spatial light modulator. This paper proposes an original system which combines the advantages of these two techniques to provide an integral imaging system of a reasonable viewing angle with accommodation cues.
Analysis and management of geometric distortions on multiview displays with only horizontal parallax
Amir Said, Bruce Culbertson
Light field (multi-view) displays are often designed to support horizontal parallax only (HPO) since this significantly reduces complexity compared to full parallax, and is commonly assumed to only cause small losses in 3D perceptual quality. In reality all HPO displays can produce severe geometric distortions because they use different projections in the horizontal and vertical directions. These distortions depend on the observer's position, and can only be eliminated in pre-defined viewing distances. In this paper we extend previous work on the theoretical analysis of the problem to create tools to manage the problem, enabling creators of multi-view 3D content to keep the distortion within acceptable ranges for all objects in a 3D scene, and all expected viewing positions. We present examples of simulated views of HPO displays, which demonstrate how the distortions can affect visual appearance, and how they are managed.
Mixed-resolution view synthesis using non-local means refined image merging
Thomas Richter, Michael Schöberl, Jürgen Seiler, et al.
Synthesizing novel views from originally available camera perspectives via depth maps is a key issue in the 3D video domain. Up to now, several high-resolution cameras are needed to obtain high-quality intermediate synthesized views. One possibility to reduce costs with regard to the used camera array is to replace some cameras by low-resolution cameras, which are cheaper on the one hand, but provide a much poorer image quality on the other hand. Unfortunately, some of the information inside the desired intermediate view may only be available in the low-resolution reference. Thus, the image quality of the low-resolution reference has a big influence on the visual quality of the synthesized view. This paper proposes a postprocessing step for the synthesized view, based on the non-local means algorithm. Thereby, all areas inserted from the low-resolution reference get efficiently adapted to their high-resolution environment. It is shown, that the non-local means refined image merging leads to a PSNR gain of up to 0.90 dB compared to an unrefined mixed-resolution setup. The approach can be easily extended to a hole-filling algorithm and yields a PSNR gain of up to 0.81 dB for hole areas compared to a reference hole-filling algorithm. The subjective image quality also increases convincingly in both applications.
Interactive Paper Session: Stereoscopic Perception and Quality
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Correlation between a perspective distortion in a S3D content and the visual discomfort perceived
D. Doyen, J.-J. Sacré, L. Blondé
Perspective distortion will occur in stereoscopic 3D (S3D) when the relative disparity between elements generates a depth not in accordance with the relative size of the presented objects. Subjective tests have been conducted using test sequences where shooting parameters are perfectly known and where vergence/accommodation conflict is not predominant. Perspective distortions will occur with some of the sequences, depending on viewing conditions. People were asked to qualify sequences in term of naturalness and visual comfort. Results of test revealed a clear correlation between perspective conflict and visual discomfort perceived. Whatever the shooting condition, parallel or toed-in cameras, results are similar. A factor between depth and perspective can be calculated for each shooting configuration and viewing condition. This factor seems a relevant indicator to evaluate the comfort of S3D content perception. Subjective tests allowed to better understand the link between perspective conflicts and visual comfort. Next, studies will be conducted to extend these tests to cinema conditions were the range of viewing conditions is larger.
Objective view synthesis quality assessment
Pierre-Henri Conze, Philippe Robert, Luce Morin
View synthesis brings geometric distortions which are not handled efficiently by existing image quality assessment metrics. Despite the widespread of 3-D technology and notably 3D television (3DTV) and free-viewpoints television (FTV), the field of view synthesis quality assessment has not yet been widely investigated and new quality metrics are required. In this study, we propose a new full-reference objective quality assessment metric: the View Synthesis Quality Assessment (VSQA) metric. Our method is dedicated to artifacts detection in synthesized view-points and aims to handle areas where disparity estimation may fail: thin objects, object borders, transparency, variations of illumination or color differences between left and right views, periodic objects... The key feature of the proposed method is the use of three visibility maps which characterize complexity in terms of textures, diversity of gradient orientations and presence of high contrast. Moreover, the VSQA metric can be defined as an extension of any existing 2D image quality assessment metric. Experimental tests have shown the effectiveness of the proposed method.
Depth enhancement of S3D content and the psychological effects
Masahiro Hirahara, Saki Shiraishi, Takashi Kawai
Stereoscopic 3D (S3D) imaging technologies are widely used recently to create content for movies, TV programs, games, etc. Although S3D content differs from 2D content by the use of binocular parallax to induce depth sensation, the relationship between depth control and the user experience remains unclear. In this study, the user experience was subjectively and objectively evaluated in order to determine the effectiveness of depth control, such as an expansion or reduction or a forward or backward shift in the range of maximum parallactic angles in the cross and uncross directions (depth bracket). Four types of S3D content were used in the subjective and objective evaluations. The depth brackets of comparison stimuli were modified in order to enhance the depth sensation corresponding to the content. Interpretation Based Quality (IBQ) methodology was used for the subjective evaluation and the heart rate was measured to evaluate the physiological effect. The results of the evaluations suggest the following two points. (1) Expansion/reduction of the depth bracket affects preference and enhances positive emotions to the S3D content. (2) Expansion/reduction of the depth bracket produces above-mentioned effects more notable than shifting the cross/uncross directions.
Perception of size and shape in stereoscopic 3D imagery
Michael D. Smith, Bradley T. Collar
This paper explores the mathematical relationships between the scene geometry, camera parameters, and viewing environment and their influence on the viewer's perception of 3D. The current practice of using horizontal image translation to set convergence has an effect on the shape ratio and 3D magnification factor of the resulting images and is not well understood by the industry. This paper examines the gap between the creative processes used by stereographers and the mathematical relationships affected by those creative processes. Examples images varying the aforementioned parameters will be demonstrated.
Quality of experience model for 3DTV
Wei Chen, Jérôme Fournier, Marcus Barkowsky, et al.
Modern stereoscopic 3DTV brings new QoE (quality of experience) to viewers, which not only enhances the 3D sensation due to the added binocular depth, but may also induce new problems such as visual discomfort. Subjective quality assessment is the conventional method to assess the QoE. However, the conventional perceived image quality concept is not enough to reveal the advantages and the drawbacks of stereoscopic images in 3DTV. Higher-level concepts such as visual experience were proposed to represent the overall visual QoE for stereoscopic images. In this paper, both the higher-level concept quality indicator, i.e. visual experience and the basic level concepts quality indicators including image quality, depth quantity, and visual comfort are defined. We aim to explore 3D QoE by constructing the visual experience as a weight sum of image quality, depth quantity and visual comfort. Two experiments in which depth quantity and image quality are varied respectively are designed to validate this model. In the first experiment, the stimuli consist of three natural scenes and for each scene, there are four levels of perceived depth variation in terms of depth of focus: 0, 0.1, 0.2 and 0.3 diopters. In the second experiment, five levels of JPEG 2000 compression ratio, 0, 50, 100, 175 and 250 are used to represent the image quality variation. Subjective quality assessments based on the SAMVIQ method are used in both experiments to evaluate the subject's opinion in basic level quality indicators as well as the higher-level indicator. Statistical analysis of result reveals how the perceived depth and image quality variation affect different perceptual scales as well as the relationship between different quality aspects.
Towards adapting current 3DTV for an improved 3D experience
L. Blondé, D. Doyen, C. Thébault, et al.
Recent upgrades of HDTV into 3DTV resulted in impairments in displaying stereo contents. One of the most critical flaws is probably crosstalk and the resultant ghosting effect impairing the 3D experience. The purpose of this study is to identify the primary source of crosstalk, throughout the full image generation and viewing chain, for a selection of 3D displays: Liquid Crystal Display (LCD) and Plasma Display Panel (PDP) combined with different active glasses technologies. Time measurements have been carried out on various display panels and shutter glasses technologies. For each technology, the crosstalk is a complex combination of several factors depending on display panels, shutter glasses and their synchronization, and ghost busting. The study tried to discriminate the main sources of crosstalk in each case, and to simulate the effect of various display panels or shutter glasses performance optimizations. Analysis and conclusions vary depending on the display technology. For LCD, light leakage at the panel level appears the first cause of crosstalk, and, in a second step, optimization of the shutter glasses. For PDP the use of more adapted shutter glasses can mitigate color distortion effects.
Interactive Paper Session: 3D Displays
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Integral volumetric imaging with high resolution and smooth motion parallax
This paper proposes a high resolution integral imaging system using a lens array composed of non-uniform decentered elemental lenses. One of the problems of integral imaging is the trade-off relationship between the resolution and the number of views. When the number of views is small, motion parallax becomes strongly discrete to maintain the viewing angle. The only conventional way to solve this problem is to use a finer lens array and a display panel with a finer pixel pitch. In the proposed method large display area is used to show a smaller and finer 3D image. To realize it, the elemental lenses should be smaller than the elemental lenses. To cope with the difference of sizes between the elemental images and the elemental lenses, the lens array is designed so that the optical centers of elemental lenses are located in the centers of elemental images, not in the centers of elemental lenses. In addition, new image rendering algorithm is developed so that undistorted 3D image can be presented with a non-uniform lens array. The proposed design of lens array can be applied to integral volumetric imaging, where display panels are layered to show volumetric images in the scheme of integral imaging.
Enlargement of viewing freedom of reduced-view SMV display
Junya Nakamura, Taichi Takahashi, Yasuhiro Takaki
In order to reduce the resolution of a flat-panel display used for the super multi-view (SMV) display, we previously proposed a reduced-view SMV display that generates views only around a viewer's left and right eyes. A face-tracking system with one camera was combined with the reduced-view SMV display to enlarge the viewing freedom. However, the viewing freedom in the depth direction was limited. In the present study, we propose a SMV display system which generates views corresponding to three-dimensional (3D) positions of the viewer's eyes to enlarge the viewing freedom in both the horizontal and depth directions. An eye-tracking system with a stereo camera is combined with the previously developed reduced-view SMV display. Pixels on the flat-panel display that are seen through each cylindrical lens are determined geometrically for all of the cylindrical lenses. Parallax images are generated corresponding to the 3D positions of the viewer's eyes. To achieve the SMV display condition, two or more consecutive pixels including the determined pixels are used to display the parallax images. The enlargement of the viewing freedom was confirmed by the experiments.
Color hologram generation using depth map of real objects with viewing-zone-angle expansion
Kosuke Nomura, Ryutaro Oi, Taiichiro Kurita, et al.
Holography is the ultimate 3D image technology which can display natural 3D images for humans because it records and reconstructs the wavefront from objects. Previously, we had studied the holography of real scenes and proposed a color hologram generation method using the same viewpoint for images of a real scene; i.e., color image and depth map. Although the images reconstructed from the hologram were in full color and in a high-resolution format called 8K4K, the observed range was only 5.6 degrees, which was insufficient. In this paper, we propose a hologram generation method with viewing-zone-angle expansion. First, object beams are calculated for the light that propagates in the different directions and satisfies the maximum diffraction angle. Second, holograms reconstructing the different viewing-zone- angles are generated by irradiating with reference beams that have different incidence angles. As an experimental result, the reconstructed images were observed over a wide range and we confirmed the effectiveness of the proposed method. At this time, to apply a method which calculates the light propagation with FFTs because the amount of calculation had tripled, we confirmed that the processing speed is nine times faster than that achieved previously.
Stereoscopic surround displays using interference filters
Silvio Peikert, Jérémie Gerhardt
To achieve stereoscopy on surround displays interference filters have some advantages over other techniques. However these filters introduce strong color differences between the projectors, which may reveal that the display is compound by multiple projectors. This article presents methods for a computationally efficient correction of the colorimetric properties of multi-projector surround displays. This correction is based on automated measurements by multiple cameras and a spectrometer. The described methods were validated by applying them to a stereoscopic dome display made up of 16 high definition projectors equipped with Infitec filters. On that display we achieved a significant improvement of the colorimetric properties compared to regular soft-edge blending. Our reference setup shows that the multi-projector approach combined with interference filters allows to build highly immersive stereoscopic surround displays fulfilling today's requirements on spatial resolution, frame rates and interaction latencies.
Design of extended viewing zone at autostereoscopic 3D display based on diffusing optical element
Min Chang Kim, Yong Seok Hwang, Suk-Pyo Hong, et al.
In this paper, to realize a non-glasses type 3D display as next step from the current glasses-typed 3D display, it is suggested that a viewing zone is designed for the 3D display using DOE (Diffusing Optical Element). Viewing zone of proposed method is larger than that of the current parallax barrier method or lenticular method. Through proposed method, it is shown to enable the expansion and adjustment of the area of viewing zone according to viewing distance.
Floating image device with autostereoscopic display and viewer-tracking technology
Chang-Ying Chen, Kun-Lung Tseng, Chy-Lin Wang, et al.
Now, numerous types of 3D display have been developed or under-developing. However, most of them present stereoscopic images in a space with limited distance from the physical screen. A display which can deliver stereoscopic images in the free space and satisfies the touching sense of viewers is always expected. As a result, we proposed a floating image device with auto-stereoscopic display and viewer tracking technology. The key technology includes that the optical projected lenses with wide view angle which exceeds 30 degrees, the optimized parameters of 2 views auto-stereoscopic display which fits the viewing specifications and the viewer tracking technology which can update the corresponding image of the particular view angle in real time. The novel display is the other choice for consumers especially for product exhibition, user interface of kiosk and a kind of apparatus of video conference, etc.
A time-sequential multiview autostereoscopic display without resolution loss using a multi-directional backlight unit and an LCD panel
Hyunkyung Kwon, Hee-Jin Choi
One of most important problems which most of the autostereoscopic display have is the degradation of resolution. In this paper, a method is proposed to resolve the degradation of resolution using a multi-directional backlight unit and an LCD panel with a time-sequential operation.
Full-resolution autostereoscopic display using an all-electronic tracking/steering system
PolarScreens is developing a new 3D display technology capable of displaying full HD resolution in each eye without the need for glasses. The technology combines a regular backlight, a 120Hz 3D LCD panel, a vertical Patterned active shutter panel and a head tracking system. The technology relies on a 12-sub-pixel wide alternated pattern encoded in the stereo image to follow the head movement. Alternatively for a passive 3D display, the barrier is made of vertical strip Polarizer Film. This can be applied to any full resolution polarized display like iZ3D, Perceiva, or active retarder 3D display. The end result is a full resolution autostereoscopic display with complete head movement freedom. There are no mechanical moving part (like lenticular) or extra active components to steer the correct L/R image to the user's eyes. The new display has the capacity of displaying 2D/3D information on a pixel per pixel base so there is no need for full screen or windowed 2D/3D switchable apparatus.
Design of crossed-mirror array to form floating 3D LED signs
Hirotsugu Yamamoto, Hiroki Bando, Ryousuke Kujime, et al.
3D representation of digital signage improves its significance and rapid notification of important points. Our goal is to realize floating 3D LED signs. The problem is there is no sufficient device to form floating 3D images from LEDs. LED lamp size is around 1 cm including wiring and substrates. Such large pitch increases display size and sometimes spoils image quality. The purpose of this paper is to develop optical device to meet the three requirements and to demonstrate floating 3D arrays of LEDs. We analytically investigate image formation by a crossed mirror structure with aerial aperture, called CMA (crossed-mirror array). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. We have fabricated CMA for 3D array of LEDs. One CMA unit contains 20 x 20 apertures that are located diagonally. Floating image of LEDs was formed in wide range of incident angle. The image size of focused beam agreed to the apparent aperture size. When LEDs were located three-dimensionally (LEDs in three depths), the focused distances were the same as the distance between the real LED and the CMA.
Interactive Paper Session: Multiview Image Methods
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Novel multiview generation framework for 3D displays
In this paper, we propose a novel multi-view generation framework that considers the spatiotemporal consistency of each synthesized multi-view. Rather than independently filling in the holes of individual generated images, the proposed framework gathers hole information from each synthesized multi-view image to a reference viewpoint. The method then constructs a hole map and a SVRL (single view reference layer) at the reference viewpoint before restoring the holes in the SVRL, thereby generating a spatiotemporally consistent view. A hole map is constructed using depth information of the reference viewpoint and the input/output baseline length ratio. Thus, the holes in the SVRL can also represent holes in other multi-view images. To achieve temporally consistent hole filling in the SVRL, the restoration of holes in the current SVRL is performed by propagating the pixel value of the previous SVRL. Further hole filling is performed using a depth- and exemplar-based inpainting method. The experimental results showed that the proposed method generates high-quality spatiotemporally consistent multi-view images in various input/output environments. In addition, the proposed framework decreases the complexity of the hole-filling process by reducing repeated hole filling.
Calibration of multiview camera with parallel and decentered image sensors
M. Ali-Bey, S. Moughamir, N. Manamanni
This paper focuses on the calibration problem of a multi-view shooting system designed for the production of 3D content for auto-stereoscopic visualization. The considered multi-view camera is characterized by coplanar and decentered image sensors regarding to the corresponding optical axis. Based on the Faugéras and Toscani's calibration approach, a calibration method is herein proposed for the case of multi-view camera with parallel and decentered image sensors. At first, the geometrical model of the shooting system is recalled and some industrial prototypes with some shooting simulations are presented. Next, the development of the proposed calibration method is detailed. Finally, some simulation results are presented before ending with some conclusions about this work.
Inversion-free multiview subpixel rendering for natural 3D presentation
In this paper, an inversion-free subpixel rendering method that uses eye tracking in a multiview display is proposed. The multiview display causes an inversion problem when one eye of the user is focused on the main region and the other eye is focused on the side region. In the proposed method, the subpixel values are rendered adaptively depending on the eye position of the user to solve the inversion problem. Also, to enhance the 3D resolution without the color artifact, the subpixel rendering algorithm using subpixel area weighting is proposed instead of the pixel values. In the experiments, 36-view images were seen using active subpixel rendering with the eye tracking system in a four-view display.
Wide-viewing angle three-dimensional display based on the ray reconstruction method using multiple micro-projectors
Hideya Takahashi, Kenta Hirooka, Kenji Yamada
We propose an omnidirectional three-dimensional (3D) display system. This is a tool for communication around a 3D image among a small number of people. This 3D display system consists of multiple basic 3D display units. The basic unit consists of a micro-projector, a lenticular lens array sheet, and a cylindrical lens. In this basic unit, since a screen is not used, the light rays from a micro-projector pass through a lenticular lens array sheet and observed directly. Thus, the spatial density distribution of projected light rays is partial. To average the spatial density of projected light rays, we use a cylindrical lens. To increase the viewing angle, we aligned multiple basic units in a circle, and displayed 3D images at the center of the circle. To verify the effectiveness of the proposed 3D display, we constructed the prototype system. This prototype consists of 8 basic units. They are aligned 18-degree apart in a circle and the radius is 95 mm. The maximum size of displayed 3D images is 35 mm x 40 mm x 35 mm. The viewing angle of a 3D image is 124-degree. This paper describes the principle of proposed 3D display system, and also describes the experimental results.
Multi-layered see-through movie in diminished reality
Yuko Uematsu, Takanori Hashimoto, Takuya Inoue, et al.
This paper presents generating a multi-layered see-through movie for an auto-stereoscopic display. This work is based on Diminished Reality (DR), which is one of the research fields of Augmented Reality (AR). In the usual AR, some virtual objects are added on the real world. On the other hand, DR removes some real objects from the real world. Therefore, the background is visualized instead of the real objects (obstacles) to be removed. We use multiple color cameras and one TOF depth camera. The areas of obstacles are defined by using the depth camera based on the distance of obstacles. The background behind the obstacles is recovered by planarprojection of multiple cameras. Then, the recovered background is overlaid onto the removed obstacles. For visualizing it through the auto-stereoscopic display, the scene is divided into multiple layers such as obstacles and background. The pixels corresponding to the obstacles are not visualized or visualized semi-transparently at the center viewpoints. Therefore, we can see that the obstacles are diminished according to the viewpoints.
An independent motion and disparity vector prediction method for multiview video coding
The inter-view prediction is used as well as the temporal prediction in order to exploit both the temporal and inter-view redundancies in multiview video coding. Accordingly, the multiview video coding has two types of motion vectors that are the temporal motion vector and the disparity vector, respectively. The disparity vector is generally uncorrelated with the temporal motion vector. However, they are used together to predict the motion vector regardless of their types, therefore an efficiency of the conventional predictive coding of multiview video coding is decreased. In order to increase the accuracy of the predicted motion vector, a new motion vector prediction method including virtual temporal motion vector and virtual disparity vector is proposed for both the multiview video and multiview video plus depth formats. The experimental results show that the proposed method can reduce the coding bitrates by 6.5% in average and 14.6% at maximum in terms of Bjontegaard metric compared to the conventional method.
Geometry compensation using depth and camera parameters for three-dimensional video coding
One of the important issues for a next generation broadcasting system is how to compress a massive amount of threedimensional (3D) video efficiently. In this paper, we propose a geometry compensation method for 3D video coding exploiting color videos, depth videos and camera parameters. In the proposed method, we first generate a compensated view, which is located at the geometrically same position with the current view, using depth and camera parameters of neighboring views. Then, the compensated view is used as a reference picture to reduce the inter-view redundancies such as disparity and motion vectors. Furthermore, considering the direction of hole-regions, we propose a hole-filling method for picture of P-view to fill up the holes based on the neighboring background pixels. The experimental results show that the proposed algorithm increases BD-PSNRs up to 0.22dB and 0.63dB for P- and B-views, respectively. Meanwhile, we achieved up to 6.28% and 18.32% BD bit-rates gain for P- and B- views, respectively.
Converting conventional stereo pairs to multiview sequences using morphing
Roger Olsson, Vamsi Kiran Adhikarla, Sebastian Schwarz, et al.
Autostereoscopic multi view displays require multiple views of a scene to provide motion parallax. When an observer changes viewing angle different stereoscopic pairs are perceived. This allows new perspectives of the scene to be seen giving a more realistic 3D experience. However, capturing arbitrary number of views is at best cumbersome, and in some occasions impossible. Conventional stereo video (CSV) operates on two video signals captured using two cameras at two different perspectives. Generation and transmission of two views is more feasible than that of multiple views. It would be more efficient if multiple views required by an autostereoscopic display can be synthesized from these sparse set of views. This paper addresses the conversion of stereoscopic video to multiview video using the video effect morphing. Different morphing algorithms are implemented and evaluated. Contrary to traditional conversion methods, these algorithms disregard the physical depth explicitly and instead generate intermediate views using sparse sets of correspondence features and image morphing. A novel morphing algorithm is also presented that uses scale invariant feature transform (SIFT) and segmentation to construct robust correspondences features and qualitative intermediate views. All algorithms are evaluated on a subjective and objective basis and the comparison results are presented.
Multiview video and depth compression for free-view navigation
Yuta Higuchi, Mehrdad Panahpour Tehrani, Tomohiro Yendo, et al.
In this paper, we discuss a multiview video and depth coding system for Multiview video applications such as 3DTV and Free View-point Television (FTV) 1. We target an appropriate multiview and depth compression method. And then we investigate the effect on free view synthesis quality by changing the transmission rates between multiview and depth sequences. In the simulations, we employ MVC in parallel to compress the multiview video and depth sequences at different bitrates, and compare the virtual view sequences generated by decoded data with the original video sequences taken in the same viewpoint. Our experimental results show that bitrates of multi depth stream has less effect on the view synthesis quality compared with the multi view stream.
A layered inpainting method for virtual view synthesis
Seona Kim, Kyong Joon Lee, Chan Kim, et al.
In this paper, we presented a new approach in view synthesis based on the concept of missing area being filled with the background parts. Viewing synthesis is a method to generate a virtual scene in a desired view point. Previous approaches generally assumed that a virtual camera located between a pair of reference cameras. In contrast, we consider the case where the virtual camera located outside the reference cameras. The contents consist of two parts: layer separation and layer inpainting. In the layer separation, it extracts the background part from the images. The part is essential since layer inpainting inferred the result of it. After that, layer inpainting is implied to fill the occlusion region with the background layer. Therefore, it significantly improve the quality of inpainting in view synthesis. It should be noted that this research has only examined with image set from the Microsoft research yet. It has clear boundary between object and background, but patch based inpainting is applied in this framework. It is suggested that future studies can use better inpainting method in order to enhance the accuracy of indicator.
Analysis on ray reconstruction characteristics of multiview and integral imaging display
Hee-Seung Kim, Hyun-Eui Kim, Kyeong-Min Jeong, et al.
We performed a comparative analysis for multi-view autostereoscopic display and horizontal parallax only integral imaging display. The spatio-angular ray distribution reconstructed by two technologies is calculated and used as a metric to evaluate the three-dimensional image reconstruction quality. Based on the ray reconstruction characteristics, we also propose a method to convert a set of perspective images for multi-view displays to a set of orthographic images for integral imaging display.
A content-based method for perceptually driven joint color/depth compression
E. Bosc, L. Morin, M. Pressigout
Multi-view Video plus Depth (MVD) data refer to a set of conventional color video sequences and an associated set of depth video sequences, all acquired at slightly different viewpoints. This huge amount of data necessitates a reliable compression method. However, there is no standardized compression method for MVD sequences. H.264/MVC compression method, which was standardized for Multi-View-Video representation (MVV), has been the subject of many adaptations to MVD. However, it has been shown that MVC is not well adapted to encode multi-view depth data. We propose a novel option as for compression of MVD data. Its main purpose is to preserve joint color/depth consistency. The originality of the proposed method relies on the use of the decoded color data as a prior for the associated depth compression. This is meant to ensure consistency in both types of data after decoding. Our strategy is motivated by previous studies of artifacts occurring in synthesized views: most annoying distortions are located around strong depth discontinuities and these distortions are due to misalignment of depth and color edges in decoded images. Thus the method is meant to preserve edges and to ensure cosistent localization of color edges and depth edges. To ensure compatibility, colored sequences are encoded with H.264. Depth maps compression is based on a 2D still image codec, namely LAR (locally adapted resolution). It consists in a quad-tree representation of the images. The quad-tree representation contributes in the preservation of edges in both color and depth data. The adopted strategy is meant to be more perceptually driven than state-of-the-art methods. The proposed approach is compared to H.264 encoding of depth images. Objective metrics scores are similar with H.264 and with the proposed method, and visual quality of synthesized views is improved with the proposed approach.
Interactive Paper Session: Stereoscopic Image Methods
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Efficient panoramic sampling of real-world environments for image-based stereoscopic telepresence
Luis E. Gurrieri, Eric Dubois
A key problem in telepresence systems is how to effectively emulate the subjective experience of being there delivered by our visual system. A step toward visual realism can be achieved by using high-quality panoramic snapshots instead of computer-based models of the scene. Furthermore, a better immersive illusion can be created by enabling the free viewpoint stereoscopic navigation of the scene, i.e. using omnistereoscopic imaging. However, commonly found implementation constraints of telepresence systems such as acquisition time, rendering complexity, and storage capacity, make the idea of using stereoscopic panoramas challenging. Having these constraints in mind, we developed a technique for the efficient acquisition and rendering of omnistereoscopic images based on sampling the scene with clusters of three panoramic images arranged in a controlled geometric pattern. Our technique can be implemented with any off-the-shelf panoramic cameras. Furthermore, it does not require neither the acquisition of additional depth information of the scene nor the estimation of camera parameters. The low the computational complexity and reduced data overhead of our rendering process make it attractive for the large scale stereoscopic sampling in a variety of scenarios.
Partial 2D to S3D conversion and the cognitive characteristics
2D to stereoscopic 3D (S3D) conversion methods, which is one approach to creating S3D content, are divided into automatic "on-line" and manual "off-line" methods. Off-line conversion of 2D to S3D is expensive, but offers higher S3D image quality. Moreover, while off-line conversion provides more flexible control over parallax than stereo filming, in most cases, 2D images are converted according to the monocular depth cues. The authors propose a new method that adds uncrossed parallax to entire 2D images and crossed parallax only to specific areas. The authors conducted subjective and objective evaluations to examine the cognitive characteristics of partial 2D to S3D conversion. This paper describes the details of the proposed method and the results of the evaluations.
Disparity-compensated view synthesis for S3D content correction
Philippe Robert, Cédric Thébault, Pierre-Henri Conze
The production of stereoscopic 3D HD content is considerably increasing and experience in 2-view acquisition is in progress. High quality material to the audience is required but not always ensured, and correction of the stereo views may be required. This is done via disparity-compensated view synthesis. A robust method has been developed dealing with these acquisition problems that introduce discomfort (e.g hyperdivergence and hyperconvergence...) as well as those ones that may disrupt the correction itself (vertical disparity, color difference between views...). The method has three phases: a preprocessing in order to correct the stereo images and estimate features (e.g. disparity range...) over the sequence. The second (main) phase proceeds then to disparity estimation and view synthesis. Dual disparity estimation based on robust block-matching, discontinuity-preserving filtering, consistency and occlusion handling has been developed. Accurate view synthesis is carried out through disparity compensation. Disparity assessment has been introduced in order to detect and quantify errors. A post-processing deals with these errors as a fallback mode. The paper focuses on disparity estimation and view synthesis of HD images. Quality assessment of synthesized views on a large set of HD video data has proved the effectiveness of our method.
Virtual view interpolation at arbitrary view points for mixed-resolution 3D videos
For a full motion parallax 3D display, it is necessary to supply multiple views obtained from a series of different locations. However, it is impractical to deliver all of the required views because it will result in a huge size of bit streams. In the previous work, authors proposed a mixed resolution 3D video format composed of color and depth information pairs with heterogeneous resolutions, and also suggested a view synthesis algorithm for mixed resolution videos. This paper reports a more refined view interpolation method and improved results.
Efficient dense blur map estimation for automatic 2D-to-3D conversion
Focus is an important depth cue for 2D-to-3D conversion of low depth-of-field images and video. However, focus can be only reliably estimated on edges. Therefore, Bea et al. [1] first proposed an optimization based approach to propagate focus to non-edge image portions, for single image focus editing. While their approach produces accurate dense blur maps, the computational complexity and memory requirements for solving the resulting sparse linear system with standard multigrid or (multilevel) preconditioning techniques, are infeasible within the stringent requirements of the consumer electronics and broadcast industry. In this paper we propose fast, efficient, low latency, line scanning based focus propagation, which mitigates the need for complex multigrid or (multilevel) preconditioning techniques. In addition we propose facial blur compensation to compensate for false shading edges that cause incorrect blur estimates in people's faces. In general shading leads to incorrect focus estimates, which may lead to unnatural 3D and visual discomfort. Since visual attention mostly tends to faces, our solution solves the most distracting errors. A subjective assessment by paired comparison on a set of challenging low-depth-of-field images shows that the proposed approach achieves equal 3D image quality as optimization based approaches, and that facial blur compensation results in a significant improvement.
ROI-based transmission method for stereoscopic video to maximize rendered 3D video quality
A technique to improve the rendering quality of novel views for colour plus depth based 3D video is proposed. Most depth discontinuities occur around the edges of depth map objects. If information around edges of both colour and depth map images is lost during transmission, this will affect the quality of the rendered views. Therefore this work proposes a technique to categorize edge and surrounding areas into two different regions (Region Of Interests (ROIs)) and later protect them separately to provide Unequal Error Protection (UEP) during transmission. In this way the most important edge areas (vital for novel view rendering) will be more protected than other surrounding areas. This method is tested over a H.264/AVC based simulcast encoding and transmission setup. The results show improved rendered quality with the proposed ROI-based UEP method compared to Equal Error Protection (EEP) method.
Stereoscopic image-inpainting-based view synthesis algorithm for glasses-based and glasses-free 3D displays
Chang Yuan, Chris Liao, Hao Pan
We propose a new algorithm for synthesis of novel views based on existing stereo 3D imagery for both glasses-based and glasses-free 3D displays. Due to the often differing audience preferences for stereo depth perception on glasses-based displays, the range of perceived 3D depth needs to be either compressed or expanded. The proposal algorithm enables this depth adjustment through the synthesis of new virtual views, by incorporating intensity, disparity, and geometric saliency cues present in the stereo image pair. The proposed algorithm is further capable of eliminating the grid quantization artifacts, a common phenomenon when manipulating discrete image disparities. The algorithm can be also applied for generating multiple views for glasses-free 3D displays, based on the same stereo imagery. Successful results are demonstrated on real-world video datasets, and evaluated and validated by human subject studies.
Towards a real-time high-definition depth sensor with hardware-efficient stereo matching
Ke Zhang, Guanyu Yi, C.-K. Liao, et al.
In this paper, we present a hardware design of stereo matching for depth extraction. It is capable of matching high-definition images at real-time speed, producing high-quality disparity maps. The stereo algorithm comprises three major components, i.e. census transform, dynamic programming and local-adaptive voting. The census transform makes our method robust to radiometric differences. The dynamic programming method propagates information along scanlines by imposing a smoothness criterion. The local-adaptive voting further improves the matching quality, utilizing the correlation between intensity images and disparity maps. The whole algorithm is prototyped on a FPGA platform, effectively harnessing the power of parallel computing. With a working frequency of 65MHz, our design can produce high-quality 1024×768 disparity maps at 60fps.
Interactive floating windows: a new technique for stereoscopic video games
Chris Zerebecki, Brodie Stanfield, Mina Tawadrous, et al.
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.
Stereoscopic reconfiguration for 3D displays
Jean-Christophe Houde, Pierre-Marc Jodoin, François Deschênes
In this paper, we present a method to reconfigure 3D movies in order to minimize distortion when seen on a different display than the one it has been configured for. By their very nature, 3D broadcasts come with a stereoscopic pair to be seen by the left and right eyes. However, according to reasons that we ought to explain in the paper, the cameras used to shoot a movie are calibrated according to specific viewing parameters such as the screen size, the viewing distance and the eye separation. As a consequence, a 3D broadcast seen on a different display (say a home theater or a PC screen) than the one it has been configured for (say an IMAX R screen) will suffer from noticeable distortions. In this paper, we describe the relationship between the size of the 3D display, the position of the observer, and the intrinsic and extrinsic parameters of the cameras. With this information, we propose a method to reorganize the stereoscopic pair in order to minimize distortion when seen on an arbitrary display. In addition to the raw video pair, our method uses the viewing distance, a rough estimate of the 3D scene, and some basic information on the 3D display. An inpainting technique is used to fill disoccluded areas.
Interactive Paper Session: Stereoscopic Applications
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A simultaneous 2D/3D autostereo workstation
Dennis Chau, Bradley McGinnis, Jonas Talandis, et al.
We present a novel immersive workstation environment that scientists can use for 3D data exploration and as their everyday 2D computer monitor. Our implementation is based on an autostereoscopic dynamic parallax barrier 2D/3D display, interactive input devices, and a software infrastructure that allows client/server software modules to couple the workstation to scientists' visualization applications. This paper describes the hardware construction and calibration, software components, and a demonstration of our system in nanoscale materials science exploration.
Interactive stereoscopic visualization of large-scale astrophysical simulations
Ralf Kaehler, Tom Abel
In the last decades three-dimensional, time-dependent numerical simulations have become a standard tool in astrophysics and cosmology. This gave rise to a growing demand for analysis methods that are tailored to this type of simulation data, for example high-quality visualization approaches such as direct volume rendering and the display of stream lines. The modelled phenomena in numerical astrophysics usually involve complex spatial and temporal structures, and stereoscopic display techniques have proven to be particularly beneficial to clarify the spatial relationships of the relevant features. In this paper we present a flexible software framework for interactive stereoscopic visualizations of large time-dependent, three-dimensional astrophysical and cosmological simulation datasets. It is designed to enable fast and intuitive creation of complete rendering workflows, from importing datasets, the definition of various parameters, including camera paths and stereoscopic settings, to the storage of the final images in various output formats. It leverages the power of modern graphics processing units (GPUs) and supports high-quality floating-point precision throughout the whole rendering pipeline. All functionality is scriptable through Javascript. We give several application examples, including sequences produced for a number of planetarium shows.
Designing stereoscopic information visualization for 3D-TV: What can we learn from S3D gaming?
Jonas Schild, Maic Masuch
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.
A stereoscopic movie player with real-time content adaptation to the display geometry
Sylvain Duchêne, Martin Lambers, Frédéric Devernay
3D shape perception in a stereoscopic movie depends on several depth cues, including stereopsis. For a given content, the depth perceived from stereopsis highly depends on the camera setup as well as on the display size and distance. This can lead to disturbing depth distortions such as the cardboard effect or the puppet theater effect. As more and more stereoscopic 3D content is produced in 3D (feature movies, documentaries, sports broadcasts), a key point is to get the same 3D experience on any display. For this purpose, perceived depth distortions can be resolved by performing view synthesis. We propose a real time implementation of a stereoscopic player based on the open-source software Bino, which is able to adapt a stereoscopic movie to any display, based on user-provided camera and display parameters.