Proceedings Volume 6803

Stereoscopic Displays and Applications XIX

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Proceedings Volume 6803

Stereoscopic Displays and Applications XIX

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Volume Details

Date Published: 2 April 2008
Contents: 13 Sessions, 61 Papers, 0 Presentations
Conference: Electronic Imaging 2008
Volume Number: 6803

Table of Contents

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Table of Contents

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  • Front Matter: Volume 6803
  • Stereoscopic Image Quality and Image Processing
  • Volumetric Displays
  • Stereoscopic Human Factors
  • Multiview 3D Content
  • Autostereoscopic Displays I
  • Autostereoscopic Displays II
  • Digital 3D Stereoscopic Entertainment I
  • Digital 3D Stereoscopic Entertainment II
  • Medical Applications of Stereoscopy
  • Stereoscopic Display Applications
  • Integral 3D Imaging
  • Interactive Paper Session
Front Matter: Volume 6803
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Front Matter: Volume 6803
This PDF file contains the front matter associated with SPIE-IS&T Proceedings Volume 6803, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.
Stereoscopic Image Quality and Image Processing
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Reconstruction of stereoscopic imagery for visual comfort
Generally, an acquired stereoscopic image pair needs to be pre-processed geometrically before 3D viewing, because the parallax and alignment of the pair is not optimal for binocular vision. A stereo image obtained without using a specialized stereo camera system can have several problems that disrupt comfortable 3D viewing, such as insufficient or excessive baseline lengths between the two images. We present a reconstruction technique for the stereo pair images that maximizes visual comfort. First, a disparity map is generated from the stereo image by multiple footprints stereo algorithm, and then a synthetic stereomate is created using the disparity map and a right image of the given stereo pair. At this time, we adjust the disparity map to create a more realistic 3D effect. Most of the frequency disparity is reassigned to zero and the maximum disparity is revised as a parallax comfortable for human eyes. The occlusion of the synthetic stereomate is corrected by an inpainting method. Through the experiments, we could obtain a registered stereoscopic image with an optimized parallax. To evaluate the proposed technique, our results were compared with the original stereo pairs by viewing the 3D stereo anaglyphs.
Imaging artifact precompensation for spatially multiplexed 3-D displays
Joshua Napoli, Sourav R. Dey, Sandy Stutsman, et al.
We describe a projection system that presents a 20 megapixel image using a single XGA SLM and time-division multiplexing. The system can be configured as a high-resolution 2-D display or a highly multi-view horizontal parallax display. In this paper, we present a technique for characterizing the light transport function of the display and for precompensating the image for the measured transport function. The techniques can improve the effective quality of the display without modifying its optics. Precompensation is achieved by approximately solving a quadratic optimization problem. Compared to a linear filter, this technique is not limited by a fixed kernel size and can propagate image detail to all related pixels. Large pixel-count images are supported through dividing the problem into blocks. A remedy for blocking artifacts is given. Results of the algorithm are presented based on simulations of a display design. The display characterization method is suitable for experimental designs that may be dim and imperfectly aligned. Simulated results of the characterization and precompensation process are presented. RMS and qualitative improvement of display image quality are demonstrated.
Stereoscopic image quality metrics and compression
We are interested in metrics for automatically predicting the compression settings for stereoscopic images so that we can minimize file size, but still maintain an acceptable level of image quality. Initially we investigate how Peak Signal to Noise Ratio (PSNR) measures the quality of varyingly coded stereoscopic image pairs. Our results suggest that symmetric, as opposed to asymmetric stereo image compression, will produce significantly better results. However, PSNR measures of image quality are widely criticized for correlating poorly with perceived visual quality. We therefore consider computational models of the Human Visual System (HVS) and describe the design and implementation of a new stereoscopic image quality metric. This, point matches regions of high spatial frequency between the left and right views of the stereo pair and accounts for HVS sensitivity to contrast and luminance changes at regions of high spatial frequency, using Michelson's Formula and Peli's Band Limited Contrast Algorithm. To establish a baseline for comparing our new metric with PSNR we ran a trial measuring stereoscopic image encoding quality with human subjects, using the Double Stimulus Continuous Quality Scale (DSCQS) from the ITU-R BT.500-11 recommendation. The results suggest that our new metric is a better predictor of human image quality preference than PSNR and could be used to predict a threshold compression level for stereoscopic image pairs.
Methods for improving the quality of user created stereoscopic content
Maturation of the technologies enabling stereoscopic image capture and display offer attractive opportunities for enriching the user experience in hand-held devices, thus expanding possibilities of stereoscopic content creation from experienced stereoscopic practitioners to the general public. Content with inappropriate disparities or artifacts can cause negative experiences. There is therefore a need to ensure the quality of content created with a stereoscopic camera system to ensure positive user experiences and applicability of stereoscopic techniques in the mobile domain. We have investigated how the properties of a stereoscopic camera system can be characterized, and how a range of aspects in the imaging chain and display properties affect perceived disparities and artifacts in the content. Design considerations arising from adapting stereoscopic imaging to hand-held devices have been identified. We propose a methodology for disparity range optimization by basing camera geometry calculations on the limitations in viewing space extremities. A stereoscopic camera testing system with controllable camera parameters and a test scene for generating disparities has been developed to assist in evaluating contributing factors and to confirm the results. As a result, methods and equations for the stereo image calculations are assessed. This paper presents several techniques for reducing unwanted artifacts in a captured scene and improving the quality of the user-created stereoscopic content.
A novel quality metric for evaluating depth distribution of artifacts in coded 3D images
The two-dimensional quality metric Peak-Signal-To-Noise-Ratio (PSNR) is often used to evaluate the quality of coding schemes for different types of light field based 3D-images, e.g. integral imaging or multi-view. The metric results in a single accumulated quality value for the whole 3D-image. Evaluating single views -- seen from specific viewing angles -- gives a quality matrix that present the 3D-image quality as a function of viewing angle. However, these two approaches do not capture all aspects of the induced distortion in a coded 3D-image. We have previously shown coding schemes of similar kind for which coding artifacts are distributed differently with respect to the 3D-image's depth. In this paper we propose a novel metric that captures the depth distribution of coding-induced distortion. Each element in the resulting quality vector corresponds to the quality at a specific depth. First we introduce the proposed full-reference metric and the operations on which it is based. Second, the experimental setup is presented. Finally, the metric is evaluated on a set of differently coded 3D-images and the results are compared, both with previously proposed quality metrics and with visual inspection.
Volumetric Displays
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Hologlyphics: volumetric image synthesis performance system
This paper describes a novel volumetric image synthesis system and artistic technique, which generate moving volumetric images in real-time, integrated with music. The system, called the Hologlyphic Funkalizer, is performance based, wherein the images and sound are controlled by a live performer, for the purposes of entertaining a live audience and creating a performance art form unique to volumetric and autostereoscopic images. While currently configured for a specific parallax barrier display, the Hologlyphic Funkalizer's architecture is completely adaptable to various volumetric and autostereoscopic display technologies. Sound is distributed through a multi-channel audio system; currently a quadraphonic speaker setup is implemented. The system controls volumetric image synthesis, production of music and spatial sound via acoustic analysis and human gestural control, using a dedicated control panel, motion sensors, and multiple musical keyboards. Music can be produced by external acoustic instruments, pre-recorded sounds or custom audio synthesis integrated with the volumetric image synthesis. Aspects of the sound can control the evolution of images and visa versa. Sounds can be associated and interact with images, for example voice synthesis can be combined with an animated volumetric mouth, where nuances of generated speech modulate the mouth's expressiveness. Different images can be sent to up to 4 separate displays. The system applies many novel volumetric special effects, and extends several film and video special effects into the volumetric realm. Extensive and various content has been developed and shown to live audiences by a live performer. Real world applications will be explored, with feedback on the human factors.
Laser-plasma scanning 3D display for putting digital contents in free space
Hideo Saito, Hidei Kimura, Satoru Shimada, et al.
We present a novel 3D display that can show any 3D contents in free space using laser-plasma scanning in the air. The laser-plasma technology can generate a point illumination at an arbitrary position in the free space. By scanning the position of the illumination, we can display a set of point illuminations in the space, which realizes 3D display in the space. This 3D display has been already presented in Emerging Technology of SIGGRAPH2006, which is the basic platform of our 3D display project. In this presentation, we would like to introduce history of the development of the laser-plasma scanning 3D display, and then describe recent development of the 3D contents analysis and processing technology for realizing an innovative media presentation in a free 3D space. The one of recent development is performed to give preferred 3D contents data to the 3D display in a very flexible manner. This means that we have a platform to develop an interactive 3D contents presentation system using the 3D display, such as an interactive art presentation using the 3D display. We would also like to present the future plan of this 3D display research project.
A novel 3D display using two lens arrays and shift of element images
This paper presents a novel 3D display using a new principle which has the features of both Integral Imaging (II) and volumetric display. The display we propose consists of two lens arrays, a convex lens array and a concave lens array, and one 2D display moving back and forth. The two lens arrays are placed between the 2D display and observer. The concave lens array forms elemental images, and the convex lens array and the formed elemental images reproduce a depth division image like the II method. When the observer watches the 2D display through the two lens arrays, he feels that the image displayed by the 2D display is reproduced not at the position of 2D display but at a certain depth according to the position of the 2D display. So when the 2D display is moved, the reproduced image also moves to another depth position. Therefore various depth images can be reproduced by the movement of the 2D display. This is how the proposed display reconstructs 3D space. This time we introduce the optics system which can reconstruct a wireframe cube by oscillating the 2D display only a few centimeters. We also show the result of simulation of the proposing display with a ray tracing method to confirm the moving parallax.
Advances in passive imaging elements with micromirror array
We have proposed a new passive imaging optics which consists of a grid array of micro roof mirrors working as dihedral corner reflectors. Although this element forms mirror-like images at opposite side of objects, the images are real. Because the imaging principle of the proposed element is based on accumulation of rays, the design of each light path makes many kinds of devices possible. So, we propose two variations of such a device. One device consists of an array of micro retroreflectors and a half mirror, and it can also form real mirror-like images. The advantage of this device is wide range of view, because the displacement of each retororeflector is not limited on a plane unlike the roof mirror grid array. The other consists of an array of long dihedral corner reflectors. Although this structure has been already known as a roof mirror array, it can be used for imaging. This device forms two heterogeneous images. One is real at the same side of an object, and the other is virtual at the opposite side. This is a conjugate imaging optics of a slit mirror array whose mirror surface is perpendicular to the device surface. The advantage of a roor mirror array is that the real image has horizontal parallax and can be seen in air naturally.
Stereoscopic Human Factors
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Distortion of depth perception in virtual environments using stereoscopic displays: quantitative assessment and corrective measures
Michael Kleiber, Carsten Winkelholz
The aim of the presented research was to quantify the distortion of depth perception when using stereoscopic displays. The visualization parameters of the used virtual reality system such as perspective, haploscopic separation and width of stereoscopic separation were varied. The experiment was designed to measure distortion in depth perception according to allocentric frames of reference. The results of the experiments indicate that some of the parameters have an antithetic effect which allows to compensate the distortion of depth perception for a range of depths. In contrast to earlier research which reported underestimation of depth perception we found that depth was overestimated when using true projection parameters according to the position of the eyes of the user and display geometry.
Optical analysis on induction of focal accommodation using cylindrical lenses
In the present paper the authors analyze detailed optics of stereoscopic display combining cylindrical lenses and embedded striped patterns, which has been proposed to reduce the contradiction between binocular parallax and focal accommodation of the eyes. The proposed system lets the viewer see an image including high frequency striped patterns through a cylindrical lens. When the viewer is shown a striped pattern through a cylindrical lens, the depth on which his/her eyes focus depends on the inclination angle of stripes, for the cylindrical lens works as a lens with different focal length depending on the orientation of lines. To control the status of accommodation correctly, it is necessary to obtain the correspondence between the inclination angle of stripes and the focusing distance. To attain this goal we make a computer simulator to calculate the 3D optical paths. The validity of the computer simulator is confirmed by physical experiments with a cylindrical lens and a camera finder to measure the focal convergence of striped lines. We also confirm that this system can induce desired focal accommodation by measuring the eyes of the viewer seeing striped patterns through a cylindrical lens.
Evaluation of the influence on the human body of the autostereoscopic display based on the integral imaging method
We developed an autostereoscopic display based on the integral imaging (II) method to give horizontal parallax [1]. There is anxiety concerning the possibility of visual fatigue associated with stereoscopic images. This report summarizes the evaluation results. Ease of viewing and the fatigue associated with the stereoscopic vision were evaluated subjectively and objectively [2]. As a result, viewing stereoscopic images displayed by the II method was found to be easier than viewing images displayed by a conventional binocular method. There was no significant difference between fatigue in the case of stereoscopic vision with the II method and that in the case of viewing conventional 2D image. In addition, we reported the result of a medical safety evaluation [3].
Scalable 3D image conversion and ergonomic evaluation
Digital 3D cinema has recently become popular and a number of high-quality 3D films have been produced. However, in contrast with advances in 3D display technology, it has been pointed out that there is a lack of suitable 3D content and content creators. Since 3D display methods and viewing environments vary widely, there is expectation that high-quality content will be multi-purposed. On the other hand, there is increasing interest in the bio-medical effects of image content of various types and there are moves toward international standardization, so 3D content production needs to take into consideration safety and conformity with international guidelines. The aim of the authors' research is to contribute to the production and application of 3D content that is safe and comfortable to watch by developing a scalable 3D conversion technology. In this paper, the authors focus on the process of changing the screen size, examining a conversion algorithm and its effectiveness. The authors evaluated the visual load imposed during the viewing of various 3D content converted by the prototype algorithm as compared with ideal conditions and with content expanded without conversion. Sheffe's paired comparison method was used for evaluation. To examine the effects of screen size reduction on viewers, changes in user impression and experience were elucidated using the IBQ methodology. The results of the evaluation are presented along with a discussion of the effectiveness and potential of the developed scalable 3D conversion algorithm and future research tasks.
Depth control method for integral imaging using elemental image data processing
Jun Arai, Hiroshi Kawai, Masahiro Kawakita, et al.
We propose a method for controlling the depth of three-dimensional (3-D) images by processing the captured elemental image data based on an integral imaging system. Incoherent light is reflected from 3-D objects, propagates through a lens array, and is captured as a first elemental image by a capturing device. Firstly, the electric-field distribution in an arbitrary field is generated by use of the first elemental image data and the second lens array. A computer generated electric-field distribution is referred to as the "intermediate image." Next, the third lens array is assumed, and elemental images of the intermediate image formed by the third lens array are calculated. Finally, to reconstruct the 3-D images, we use a conventional display system of integral imaging. The depth of reconstructed images can be controlled according to the distance from the second lens array to the third lens array. Experimental results showed that the depth of the 3-D image was arbitrarily controlled by the proposed method.
Multiview 3D Content
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Real-time interactive 3D computer stereography for recreational applications
Atsushi Miyazawa, Motonaga Ishii, Kazunori Okuzawa, et al.
With the increasing calculation costs of 3D computer stereography, low-cost, high-speed implementation of the latter requires effective distribution of computing resources. In this paper, we attempt to re-classify 3D display technologies on the basis of humans' 3D perception, in order to determine what level of presence or reality is required in recreational video game systems. We then discuss the design and implementation of stereography systems in two categories of the new classification.
Flexible pixel compositor for autostereoscopic displays
Ruigang Yang, Subhasri Krishnan, J. Robert Heath
Autostereoscopic displays in fact show many views of the object of interest simultaneously. These individual views have to be re-shuffled to fit the final display. This composition task is usually done as an off-line process. We present in this paper a flexible pixel compositor that bridges the image generator (e.g., a rendering cluster) and the final display devices (such as a set of over-lapping projectors to form an ultra-high-resolution display). Our compositor is capable of performing an arbitrary mapping of pixels from any input frame to any output frame, and executing typical composition operations (e.g., blending) at the same time. To the best of our knowledge, our design is the only compositor that allows non-block based per-pixel warping and composition. This is particularly important for lenticular displays in which the different views have to be interleaved in the frame buffer. In this paper, we present an initial hardware prototype and some preliminary results in the firmware development.
Adaptive filters for depth from stereo and occlusion detection
In this paper we present two novel techniques developed in the context of the stereo to multi-view conversion research at Philips in support of the introduction of stereoscopic and auto-stereoscopic. First, we show that we can use a relatively simple filtering approach, based on the recently popular bilateral filters, to address the correspondence problem, which is at the heart of depth and motion estimation. The proposed recursive filter uses Gaussian kernels to filter best matches and to incorporate image-based constraints. It iteratively refines the depth values starting from a random initialization and converges in a limited number of iterations to a time-stable high-quality depth map. The second contribution of the paper is an occlusion detection method that uses robust filtering for the detection of occlusion that is primarily based on the analysis of the variation of the matching metric used in the disparity estimation process. The basic underlying ideas behind the occlusion detection method are (1) that occluded areas are highly likely to be located near image boundaries (where luminance or color changes abruptly), and (2) occluded regions are characterized by a large decrease in the quality of the matching metric across these boundaries. The two algorithms were tested on real-world stereoscopic video content showing promising results.
GPU-based algorithms for optimized visualization and crosstalk mitigation on a multiview display
Atanas Boev, Kalle Raunio, Atanas Gotchev, et al.
In this contribution, we present two GPU-optimized algorithms for displaying the frames of 2D-plus-Z stream on a multiview 3D display. We aim at mitigating the cross-talk artifacts, which are inherent for such displays. In our approach, a 3D mesh is generated using the given depth map, then textured by the given 2D scene and properly interdigitized on the screen. We make use of the GPU built-in libraries to perform these operations in a fast manner. To reduce the global crosstalk presence, we investigate two approaches. In the first approach, the 2D image is appropriately smoothed before texturing. The smoothing is done in horizontal direction by a 1-D filter bank driven by the given depth map. Such smoothing provides the needed anti-aliasing at the same filtering step. In the second approach, we introduce a higher number of properly blended virtual views than the display views supported and demonstrate that this is equivalent to a smoothing operation. We provide experimental results and discuss the performance and computational complexity of the two approaches. While the first approach is more appropriate for higher-resolution displays equipped with newer graphical accelerators, the latter approach is more general and suitable for lower-resolution displays and wider range of graphic accelerators.
Autostereoscopic Displays I
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An autostereoscopic display with high resolution and large number of view zones
Wu-Li Chen, Wei-Liang Hsu, Chao-Hsu Tsai, et al.
For a spatial-multiplexed 3D display, trade-off between resolution and number of view-zones are usually unavoidable due to the limited number of pixels on the screen. In this paper, we present a new autostereoscopic system, named as "integrated-screen system," to substantially increase the total number of pixels on the screen, which in turn increase both the resolution and number of view-zones. In the integrated-screen system, a large number of mini-projectors are arrayed and the images are tiled together without seams in between. For displaying 3D images, the lenticular screen with predesigned tilted angle is used for distributing different viewing zones. In order to achieve good performance, we design a brand-new projector with special lens set to meet the low-distortion requirement because the distortion of the image will induce serious crosstalk between view-zones. The proposed system has two advantages. One is the extensibility of the screen size. The size of the display can be chosen based on the applications we deal with, including the size of the projected pixel and the number of viewing zones. The other advantage is that the integrated-screen system provides projected pixels in great density to solve the major problem of the poor resolution that a lenticular-type 3D display has.
Large holographic displays as an alternative to stereoscopic displays
3D displays comprise stereoscopic displays and holographic displays. Eye convergence and accommodation are important depth cues for human vision. Stereoscopic displays provide only convergence information whereas holographic displays also provide accommodation information. Due to the inherently better 3D quality we consider holographic displays as the preferred alternative to stereoscopic displays. Our new approach to holographic displays omits unnecessary wavefront information and significantly reduces the requirements on the resolution of the spatial light modulator and the computation effort compared to conventional holographic displays. We verified our concept with holographic display prototypes and measurements. SeeReal's approach makes holographic displays feasible as a consumer product for mass-market applications.
Multiview multiperspective time multiplexed autostereoscopic display
The implementation of a time multiplexed display capable of eight simultaneously visible viewing zones will be described. The system employs a high speed digital micromirror device (DMD) to allow for the high framerate essential for flicker free display of multiple viewing zones. A combination of custom graphical processor unit (GPU) programming and a correspondingly optimized field programmable gate array (FPGA) DMD driver allows for real time interactive rendering of scenes. The rendering engine is entirely based on off the shelf with the use of a standard DVI-D interface for data transfer to the DMD interface. A rapidly switched LED light engine is employed to overcome the speed limitations of color wheel light sources, as well as providing a highly saturated color gamut. Selection of viewing zones is achieved by the use of a high-speed shutter interfaced directly to the DMD driver for precise synchronization.
Autostereoscopic Displays II
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1-inch diagonal transflective 2D and 3D LCD with HDDP arrangement
Shin-ichi Uehara, Tsutomu Hiroya, Hidenori Kusanagi, et al.
We have developed a 1-inch diagonal transflective 2D/3D-LCD with a novel pixel arrangement, called HDDP (Horizontally Double-Density Pixels). In the HDDP arrangement, both horizontal and vertical resolutions are equal, which not only results in high 3D image quality, but also means that 2D images, such as characters, can be displayed perfectly. With this design, both 3D and 2D images can be displayed simultaneously in the same picture with no need for 2D/3D mode-conversion. In order to avoid increasing power consumption, we chose to use a lenticular lens and a transflective mode which employs ambient light. In transflective mode, so as not to reduce the 3D visible zone, we use a horizontal stripe reflector, which divides each dot into a transmissive region and a reflective region vertically, without dividing the 3D visible zone into transmissive or reflective zones. As a result, a wide 3D visible zone has been achieved. In addition, in order to avoid image degradation caused by a combination of a micro structure on the reflector and a lenticular lens, we optimized the micro structure and defocused the lenticular lens. Its small size, high visibility and lowpower consumption can broaden the applications of 3D displays.
Time-multiplexing display module for high-density directional display
The new high-density directional (HDD) display using the time-multiplexing technique is proposed to reduce the complexity of the multi-projection system used for the HDD display. The HDD display is a natural three-dimensional display which has been developed to solve the visual fatigue problem caused by the accommodation-vergence conflict. The proposed HDD display consists of multiple time-multiplexing display modules. Each module consists of an LED array, a DMD, lenses, and an aperture array. A number of directional images are displayed by the DMD at a high frame rate and the LED's emit light one after another in synchronization with the DMD. The apertures are arranged twodimensionally, and their horizontal positions are different. The LED's are arranged in a same way. All directional images displayed by the DMD pass through different apertures. Multiple modules are arranged two-dimensionally with the different horizontal positions and all images are combined by a common lens. A vertical diffuser is used as a display screen to cancel the difference of the vertical display directions. All directional images are superimposed on the vertical diffuser, and are given the different horizontal display directions. Each module generates 15 directional images at a frame rate of 60 Hz. Four modules are combined to display 60 directional images in the different horizontal directions with the angle pitch of 0.31°.
Technical solutions for a full-resolution autostereoscopic 2D/3D display technology
Hagen Stolle, Jean-Christophe Olaya, Steffen Buschbeck, et al.
Auto-stereoscopic 3D displays capable of high quality, full-resolution images for multiple users can only be created with time-sequential systems incorporating eye tracking and a dedicated optical design. The availability of high speed displays with 120Hz and faster eliminated one of the major hurdles for commercial solutions. Results of alternative display solutions from SeeReal show the impact of optical design on system performance and product features. Depending on the manufacturer's capabilities, system complexity can be shifted from optics to SLM with an impact on viewing angle, number of users and energy efficiency, but also on manufacturing processes. A proprietary solution for eye tracking from SeeReal demonstrates that the required key features can be achieved and implemented in commercial systems in a reasonably short time.
Digital 3D Stereoscopic Entertainment I
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Beowulf 3D: a case study
This paper discusses the creative and technical challenges encountered during the production of "Beowulf 3D," director Robert Zemeckis' adaptation of the Old English epic poem and the first film to be simultaneously released in IMAX 3D and digital 3D formats.
Color management and color perception issues in a virtual reality theater
Davide Gadia, Cristian Bonanomi, Maurizio Rossi, et al.
In the last years, relevant efforts have been dedicated to the development of advanced technological solutions for immersive visualization of Virtual Reality (VR) scenarios, with particular attention to stereoscopic images formation. Among the various solution proposed, INFITECTM technology is particularly interesting, because it allows the reproduction of a more accurate chromatic range than anaglyphs or polarization-based approaches. Recently, this technology was adopted in the Virtual Theater of the University of Milan, an immersive VR installment, used for research purposes in the fields of Human-machine interaction and photorealistic, perceptual-based, visualization of virtual scenarios. In this paper, we want to present a first set of measures related to the determination of an accurate chromatic, colorimetric and photometric characterization of this visualization system. The acquired data are analyzed in order to evaluate the efective inter-calibration between the four devices and for the determination of an accurate description of the actual effect of the INFITECTM technology. This analysis will be the basis for the future integration of visual perception and color appereance principles in the visualization pipeline, and for the development of robust computational models and instruments for a correct color management in the visualization of immersive virtual environments.
Dimensionalization: converting 2D films to 3D
Andrew P. Van Pernis, Matthew S. DeJohn
A software system for the offine conversion of 2D films to 3D stereoscopic films is presented. We call this conversion process Dimensionalization. The software combines user input with automated techniques to choreograph the depth found within each shot. The Dimensionalization process is discussed from a technical and an artistic point of view. The Dimensionalization of a film requires a depth script to be defined. This script lays out the artistic choices of the director. The use of positive and negative parallax is discussed in relation to the depth script. Additionally, the relative number of objects given depth values must also be defined. The software adjusts the parallax to maintain the depth script when outputting for different display devices. Example scenarios are presented.
Original and creative stereoscopic film making
The stereoscopic cinema has become, once again, a hot topic in the film production. For filmmakers to be successful in this field, a technical background in the principles of binocular perception and how our brain interprets the incoming data from our eyes, are fundamental. It is also paramount for a stereoscopic production to adhere certain rules for comfort and safety. There is an immense variety of options in the art of standard "flat" photography, and the possibilities only can be multiply with the stereo. The stereoscopic imaging has its own unique areas for subjective, original and creative control that allow an incredible range of possible combinations by working inside the standards, and in some cases on the boundaries of the basic stereo rules. The stereoscopic imaging can be approached in a "flat" manner, like channeling sound through an audio equalizer with all the bands at the same level. It can provide a realistic perception, which in many cases can be sufficient, thanks to the rock-solid viewing inherent to the stereoscopic image, but there are many more possibilities. This document describes some of the basic operating parameters and concepts for stereoscopic imaging, but it also offers ideas for a creative process based on the variation and combination of these basic parameters, which can lead into a truly innovative and original viewing experience.
A systematized WYSIWYG pipeline for digital stereoscopic 3D filmmaking
Digital tools are transforming stereoscopic 3D content creation and delivery, creating an opportunity for the broad acceptance and success of stereoscopic 3D films. Beginning in late 2005, a series of mostly CGI features has successfully initiated the public to this new generation of highly-comfortable, artifact-free digital 3D. While the response has been decidedly favorable, a lack of high-quality live-action films could hinder long-term success. Liveaction stereoscopic films have historically been more time-consuming, costly, and creatively-limiting than 2D films - thus a need arises for a live-action 3D filmmaking process which minimizes such limitations. A unique 'systematized' what-you-see-is-what-you-get (WYSIWYG) pipeline is described which allows the efficient, intuitive and accurate capture and integration of 3D and 2D elements from multiple shoots and sources - both live-action and CGI. Throughout this pipeline, digital tools utilize a consistent algorithm to provide meaningful and accurate visual depth references with respect to the viewing audience in the target theater environment. This intuitive, visual approach introduces efficiency and creativity to the 3D filmmaking process by eliminating both the need for a 'mathematician mentality' of spreadsheets and calculators, as well as any trial and error guesswork, while enabling the most comfortable, 'pixel-perfect', artifact-free 3D product possible.
Digital 3D Stereoscopic Entertainment II
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Digital stereoscopic cinema: the 21st century
Over 1000 theaters in more than a dozen countries have been outfitted with digital projectors using the Texas Instruments DLP engine equipped to show field-sequential 3-D movies using the polarized method of image selection. Shuttering eyewear and advanced anaglyph products are also being deployed for image selection. Many studios are in production with stereoscopic films, and some have committed to producing their entire output of animated features in 3-D. This is a time of technology change for the motion picture industry.
The compatibility of consumer plasma displays with time-sequential stereoscopic 3D visualization
Andrew J. Woods, Kai S. Karvinen
Plasma display panels (PDP) are now a commonly used display technology for both commercial information display purposes and consumer television applications. Despite the widespread deployment of these displays, it was not commonly known whether these displays could be used successfully for time-sequential stereoscopic 3D visualization (i.e. using LCS 3D glasses). We therefore conducted a study to test a wide range of PDPs for stereoscopic compatibility. This paper reports on the testing of 14 consumer plasma displays. Each display was tested to establish whether the display synchronized with the incoming video signal, whether there was electronic crosstalk between alternate fields or frames, the maximum frequency at which the display would work, the time delay between the incoming video signal and the displayed images, whether the display de-interlaced interlaced video sources in a 3D compatible way, and the amount of phosphor decay exhibited by the display. The overall results show that plasma displays are not ideal for use with timesequential stereo. While roughly half of the plasma displays tested do support the time-sequential 3D technique, all of the tested displays had a maximum display frequency of 60Hz and most had long phosphor persistence which produces a lot of stereoscopic crosstalk.
The hybrid theatre
Ever since the first movie picture house was opened, experiencing the unique cinematic experience has constantly evolved. Technological advances continually guarantee that more changes will happen to create the ultimate cinematic experience. Cinema has been reincarnated time after time, from the first hand cranked silent movie to the modern day Digital Cinema. The technology used to depict the story changes; along with that change is the human thirst for a better transformation, for a more enjoyable, more encompassing, more believable, more immersive, yet simultaneously a more bewitching, entertainment experience. "In this volatile business of ours, we can ill afford to rest on our laurels, even to pause in retrospect. Times and conditions change so rapidly that we must keep our aim constantly focused on the future." --Walt Disney. 1 It has been said that "content is king". By itself, that implies a disservice to the technology that supports it. Without the technology, the content could not exist. In today's digital society; a movie can be downloaded to a handheld playback device the moment it is released. Offering these services at a cheap rate would enable studios to stay ahead of the curve, virtually eliminate video piracy and create the ability to deliver first class uncompromised content. It's only a matter of time when new released movies would be distributed this way too and people are given the choice to view in the comfort of their own homes, hand held device or view at a local theatre.
Development of 3D video and 3D data services for T-DMB
In this paper, we present motivation, system concept, and implementation details of stereoscopic 3D visual services on T-DMB. We have developed two types of 3D visual service : one is '3D video service', which provides 3D depth feeling for a video program by sending left and right view video streams, and the other is '3D data service', which provides presentation of 3D objects overlaid on top of 2D video program. We have developed several highly efficient and sophisticated transmission schemes for the delivery of 3D visual data in order to meet the system requirements such as (1) minimization of bitrate overhead to comply with the strict constraint of T-DMB channel bandwidth; (2) backward and forward compatibility with existing T-DMB; (3) maximize the eye-catching effect of 3D visual representation while reducing eye fatigue. We found that, in contrast to conventional way of providing a stereo version of a program as a whole, the proposed scheme can lead to variety of efficient and effective 3D visual services which can be adapted to many business models.
Toward 3D-IPTV: design and implementation of a stereoscopic and multiple-perspective video streaming system
3D-Video systems allow a user to perceive depth in the viewed scene and to display the scene from arbitrary viewpoints interactively and on-demand. This paper presents a prototype implementation of a 3D-video streaming system using an IP network. The architecture of our streaming system is layered, where each information layer conveys a single coded video signal or coded scene-description data. We demonstrate the benefits of a layered architecture with two examples: (a) stereoscopic video streaming, (b) monoscopic video streaming with remote multiple-perspective rendering. Our implementation experiments confirm that prototyping 3D-video streaming systems is possible with today's software and hardware. Furthermore, our current operational prototype demonstrates that highly heterogeneous clients can coexist in the system, ranging from auto-stereoscopic 3D displays to resource-constrained mobile devices.
Medical Applications of Stereoscopy
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A composition tool for creating comfortable stereoscopic images
Katharina Quintus, Michael Halle
Although stereoscopic imaging has potential value in many computer graphics applications, the design principles for creating effective three-dimensional images are not widely known in the graphics community. Poorly designed images may fail to convey convincing 3D information about the visualized scene or object. At their worst, stereo images designed without attention to physiological limits can produce the kinds of eye strain, headaches, and generally unpleasant viewing experiences that are unfortunately now associated with 3D by many people. This paper presents a graphical software application that assists the user in composing stereoscopic computer graphic images that minimize conflicting depth cues and unwanted physiological effects. This prototype application is designed to help novice users adjust parameters of the virtual stereo camera and compose stereoscopic views of three-dimensional models. Specifically, the tool detects window violations and excessive disparity, graphically displays affected regions of the object or scene, and suggests ways to minimize discomfort. The user interface refrains from using technical terms, guiding the inexperienced user to adjust underlying image parameters like camera position, camera view angle, location of image plane, viewing distance, and stereo base to match the scene, the viewing environment, and the user's preferences.
Radiation therapy planning using a volumetric 3D display: PerspectaRAD
Joshua Napoli, Sandy Stutsman, James C. H. Chu, et al.
We describe PerspectaRAD, the first tool for the review and modification of external-beam radiation therapy treatment plans with a volumetric three-dimensional display (Perspecta 1.9, Actuality Medical, Bedford, MA, USA) and a dedicated software application (PerspectaRAD, Actuality Medical). We summarize multi-institution retrospective studies that compare the system's efficacy to the incumbent 2-D display-based workflow. Contributions include: visualizing the treatment plan in a volumetric 3-D display, modifying the beam locations and performing point-and-click measurement in 3-D with a 3-D physical interface, and simultaneously viewing volumetric projections of the native CT data and isodose contours. The plans are synchronized with the hospital treatment planning system, Pinnacle3 (Philips Medical, WI, USA). In the largest of five studies, 33 plans were retrospectively randomized and replanned at three institutions, including 12 brain, 10 lung, and 11 abdomen / pelvis. The PerspectaRAD plan was as good as or better than plans created without PerspectaRAD 70% of the time. Radiation overdose regions were more likely to be obvious inside the target volume than when reviewed in the 2-D display alone. However, the planning time was longer with PerspectaRAD. The data demonstrate that PerspectaRAD facilitates the use of non-coplanar beams and has significant potential to achieve better plan quality in radiation therapy.
Teaching microsurgery to undergraduate medical students by means of high-definition stereo video microscopy: the Aachen skills lab experience
Justus Ilgner, Jonas Jae-Hyun Park, Martin Westhofen
Introduction: The master plan for innovative medical education established at RWTH Aachen Medical Faculty helped to set up an inter-disciplinary, interactive teaching environment for undergraduate medical students during their clinical course. This study presents our first experience with teaching microsurgery to medical students by means of highdefinition stereo video monitoring. Material and methods: A plastic model created for ear inspection with a handheld otoscope was modified with an exchangeable membrane resembling an eardrum plus a model of the human cochlea. We attached a 1280×1024 HD stereo camera to an operating microscope, whose images were processed online by a PC workstation. The live image was displayed by two LCD projectors @ 1280×720 pixels on a 1,25m rear-projection screen by polarized filters. Each medical student was asked to perform standard otosurgical procedures (paracentesis and insertion of grommets; insertion of a cochlear implant electrode) being guided by the HD stereoscopic video image. Results: Students quickly adopted this method of training, as all attendants shared the same high-definition stereoscopic image. The learning process of coordinating hand movement with visual feedback was regarded being challenging as well as instructive by all students. Watching the same image facilitated valuable feedback from the audience for each student performing his tasks. All students noted that this course made them feel more confident in their manual skills and that they would consider a career in a microsurgical specialty. Conclusion: High definition stereoscopy provides an easy access to microsurgical techniques for undergraduate medical students. This access not only bears the potential to compress the learning curve for junior doctors during their clinical training but also helps to attract medical students to a career in a microsurgical specialty.
Stereoscopic Display Applications
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Interactive stereoscopic viewer for cultural heritage
Nobuaki Abe, Takashi Kawai, Mami Kawaguchi, et al.
The purpose of the research project reported here is to create more life-like representations of cultural heritage items by presenting stereoscopic images based on 3D data. In this paper, the authors report on the work of archiving heritage items in China's National Palace Museum and on the development of an interactive stereoscopic viewer system. A horizontal stereoscopic representation with interactivity is examined as a method of obtaining a "depth" sensation. The aim is to represent cultural heritage from a low level close to that of the real environment, such as in a museum, and to provide tactile sensation. The viewer system consists of a 3D display using Xpol, a touch panel, and a tilt encoder. the system is controlled by a Windows PC with custom software. The touch panel works for not only general interactions, such as moving the displayed 3D images, but also offers an unusual type of interaction known as "tracing". The tilt encoder detects the angle of the display and rotates the 3D images accordingly. These interactions control the coordinates and parallax of the 3D images in real time to provide an experience similar to holding the real object directly. In addition, the authors examine the effectiveness of the viewer system through a subjective evaluation.
Stereo images from space
The Erasmus Recording Binocular (ERB1) was the first fully digital stereo camera used on the International Space Station. One year after its first utilisation, the results and feedback collected with various audiences have convinced us to continue exploiting the outreach potential of such media, with its unique capability to bring space down to earth, to share the feeling of weightlessness and confinement with the viewers on earth. The production of stereo is progressing quickly but it still poses problems for the distribution of the media. The Erasmus Centre of the European Space Agency has experienced how difficult it is to master the full production and distribution chain of a stereo system. Efforts are also on the way to standardize the satellite broadcasting part of the distribution. A new stereo camera is being built, ERB2, to be launched to the International Space Station (ISS) in September 2008: it shall have 720p resolution, it shall be able to transmit its images to the ground in real-time allowing the production of live programs and it could possibly be used also outside the ISS, in support of Extra Vehicular Activities of the astronauts. These new features are quite challenging to achieve in the reduced power and mass budget available to space projects and we hope to inspire more designers to come up with ingenious ideas to built cameras capable to operate in the hash Low Earth Orbit environment: radiations, temperature, power consumption and thermal design are the challenges to be met. The intent of this paper is to share with the readers the experience collected so far in all aspects of the 3D video production chain and to increase awareness on the unique content that we are collecting: nice stereo images from space can be used by all actors in the stereo arena to gain consensus on this powerful media. With respect to last year we shall present the progress made in the following areas: a) the satellite broadcasting live of stereo content to D-Cinema's in Europe; b) the design challenges to fly the camera outside the ISS as opposed to ERB1 that was only meant to be used in the pressurized environment of the ISS; c) on-board stereo viewing on a stereo camera has been tackled in ERB1: trade offs between OLED and LCOS display technologies shall be presented; d) HD_SDI cameras versus USB2 or Firewire; e) the hardware compression ASIC solutions used to tackle the high data rate on-board; f) 3D geometry reconstruction: first attempts in reconstructing a computer model of the interior of the ISS starting form the stereo video available.
Integral 3D Imaging
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Improvements of 3-D image quality in integral display by reducing distortion errors
Masahiro Kawakita, Hisayuki Sasaki, Jun Arai, et al.
An integral three-dimensional (3-D) system based on the principle of integral photography can display natural 3-D images. We studied ways of improving the resolution and viewing angle of 3-D images by using extremely highresolution (EHR) video in an integral 3-D video system. One of the problems with the EHR projection-type integral 3-D system is that positional errors appear between the elemental image and the elemental lens when there is geometric distortion in the projected image. We analyzed the relationships between the geometric distortion in the elemental images caused by the projection lens and the spatial distortion of the reconstructed 3-D image. As a result, we clarified that 3-D images reconstructed far from the lens array were greatly affected by the distortion of the elemental images, and that the 3-D images were significantly distorted in the depth direction at the corners of the displayed images. Moreover, we developed a video signal processor that electrically compensated the distortion in the elemental images for an EHR projection-type integral 3-D system. Therefore, the distortion in the displayed 3-D image was removed, and the viewing angle of the 3-D image was expanded to nearly double that obtained with the previous prototype system.
Formulation of coarse integral imaging and its applications
This paper formulates the notion of coarse integral imaging and applies it to practical designs of 3D displays for the purposes of robot teleoperation and automobile HUDs. 3D display technologies are demanded in the applications where real-time and precise depth perception is required, such as teleoperation of robot manipulators and HUDs for automobiles. 3D displays for these applications, however, have not been realized so far. In the conventional 3D display technologies, the eyes are usually induced to focus on the screen, which is not suitable for the above purposes. To overcome this problem the author adopts the coarse integral imaging system, where each component lens is large enough to cover pixels dozens of times more than the number of views. The merit of this system is that it can induce the viewer's focus on the planes of various depths by generating a real image or a virtual image off the screen. This system, however, has major disadvantages in the quality of image, which is caused by aberration of lenses and discontinuity at the joints of component lenses. In this paper the author proposes practical optical designs for 3D monitors for robot teleoperation and 3D HUDs for automobiles by overcoming the problems of aberration and discontinuity of images.
Integral 3D TV using ultrahigh-definition D-ILA device
Koya Suehiro, Makoto Yoshimura, Yasuyuki Haino, et al.
The integral method is one of the ideal means for forming 3D spatial images like real objects. It requires, however, extremely high-resolution device in order to satisfy sufficient resolution and wide viewing angle. The authors have been examining integral 3D television systems applying the Super Hi-Vision (SHV) system, which uses ultrahigh-definition LCOS, D-ILA devices. This paper describes the experimental integral 3D display and approaches to improve the quality of elemental images, which are projected behind the lens array, by decreasing blurs and improving registration accuracy. The display panels are four chips of D-ILA (4096 × 2160 pixels), each of which is used for R, B, G1 and G2 (pixel-offset method). The optics of the R/B projector and the G1/G2 projector are accurately aligned by a half mirror and the elemental images are formed on a 22 inches screen. The diffuser of the screen is a thin LC film with sufficient resolution and homogeneous visual field. The lens array consists of newly developed short focus lenses to enable wide viewing angle for multiple viewing. A drastic improvement of the 3D image quality has been achieved together with the electronic distortion correction technique.
Integral videography display with field sequential LCD
Takafumi Koike, Michio Oikawa, Miho Kobayashi
We developed two mobile-device size autostereoscopic integral videography (IV) displays with field sequential color (FSC) liquid crystal displays (LCDs) and micro lens arrays. IV is an autostereoscopic video technique based on integral photography. The FSC-LCD has a different backlight from that of conventional LCDs. The backlight is produced by red, blue, and green light emitting diodes (LED) instead of by cold cathode fluorescent lamps, and each LED emits light sequentially. IV based on FSC-LCD doesn't cause color moires because the FSC-LCD does not require color filters. One FSC-LCD IV display is 5-inch diagonal with 256×192 lenses and 20 ray directions. Its base FSC-LCD is 300ppi with 1280×768 pixels. The other FSC-LCD IV display is 4.5-inch diagonal with 192×150 lenses and 80 ray directions. Its base FSC-LCD is 498ppi with 1920×1200 pixels. In this paper, we first describe the problems of a previous conventional LCD-based IV displays, and then describe the principle of the IV displays based on the FSC-LCDs. Next, we analyze the IV displays by a plenoptic sampling theory. Lastly, we compare three versions of the IV displays, two based on the FSC-LCDs and one based on the conventional LCD.
Adaptive integral photography imaging with variable-focus lens array
Kensuke Ueda, Takafumi Koike, Keita Takahashi, et al.
We present a new concept of scene adaptive imaging scheme for integral photography (IP), which is named as "adaptive IP (AIP) imaging." Our proposal is to use variable focus lenses to compose the lens array for IP imaging. Our scheme will greatly enhance the potential of free-viewpoint image synthesis from IP images, because the sampling pattern of light-field can be optimized for the scene structure. We first introduce a theoretical model describing how to optimize the light field sampling for the target scene, by using our virtual camera model in the Hough transform space. We then describe our prototype implementation with 64 liquid lenses compactly arranged in an 8 by 8 matrix, and preliminary results with it. Our imaging scheme can be regarded as an example of Programmable Imaging, and will contribute to this new trend of imaging methods.
Interactive Paper Session
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Moving up to high-resolution (dual 1920x1080): acquiring and visualizing stereoscopic noncompressed images in real-time for dentists and medical applications
In this paper we define an innovative way to visualize, capture, manage, securely preserve, and playback high definition (dual 1920×1080 pixels) stereoscopic images using a modular real-time system called "Solid-Look". The "Solid-Look" system receives uncompressed dual video images at 1920×1080 pixels @60fps from high resolution cameras, it stores the synchronized footage on disk using a stereoscopic dual stream format and it displays the stereoscopic images in real-time on almost any type of display (from standard, polarized, auto-stereoscopic, holographic to single or dual projector systems) allowing multiple audience to have a concurrent stereoscopic vision. The high definition stereo cameras are synchronized and can perform zooming for a controlled and smooth vision.
3-D visualization of electrostatic fields on a helicopter in flight
John F. Dammann, David M. Hull
Aircraft in flight typically charge via electrostatic processes; this charge is the source of measurable electric fields. Nearby objects may perturb this field, so there is interest in developing electrostatic sensors that can sense nearby objects like power lines by measuring their effects on the field. A major obstacle to developing these sensors is that there are often large variations in the field due to other causes. The problem is particularly difficult for helicopters where the rotating blades cause large periodic variations in field intensity. The Army Research Laboratory (ARL) has developed a model that predicts these self-generated variations so they can be cancelled out and the smaller variations from other objects can be seen. A new code is presented that was developed at ARL for visualization of the complex fields present on helicopters. The fields are different on virtually every part of the aircraft and vary with both the main and tail rotor positions. The code combines a large number of different quasi-static calculations in a single animated display where field strengths are "painted" as textures on the aircraft model. The code allows the user to view the time variations from any viewpoint in stereo. The stereo viewing is very important for clear and easy interpretation of the complex field patterns produced by the models.
Programming standards for effective S-3D game development
Neil Schneider, Alexander Matveev
When a video game is in development, more often than not it is being rendered in three dimensions - complete with volumetric depth. It's the PC monitor that is taking this three-dimensional information, and artificially displaying it in a flat, two-dimensional format. Stereoscopic drivers take the three-dimensional information captured from DirectX and OpenGL calls and properly display it with a unique left and right sided view for each eye so a proper stereoscopic 3D image can be seen by the gamer. The two-dimensional limitation of how information is displayed on screen has encouraged programming short-cuts and work-arounds that stifle this stereoscopic 3D effect, and the purpose of this guide is to outline techniques to get the best of both worlds. While the programming requirements do not significantly add to the game development time, following these guidelines will greatly enhance your customer's stereoscopic 3D experience, increase your likelihood of earning Meant to be Seen certification, and give you instant cost-free access to the industry's most valued consumer base. While this outline is mostly based on NVIDIA's programming guide and iZ3D resources, it is designed to work with all stereoscopic 3D hardware solutions and is not proprietary in any way.
Disparity manipulation for stereo images and video
We develop a general framework for disparity manipulation and morphing for stereo images and video. The framework consists of three parts: disparity map generation, disparity map manipulating/editing, and stereo image synthesis. We first discuss disparity map generation techniques for different original input data types, including monoscopic images, monoscopic video, stereo image pairs, and stereo video. Then, we describe three methods for user manipulation of the disparity map. In the first, the user employs an interactive object-selecting tool by inputting seed points near the desired object boundary. Given the selected objects, the user defines input-output disparity mapping curves for each object. In the second method, the user arbitrary manipulates a 3D disparity surface and our system calculates the new 3D surface after the user editing. A third method provides conversions between the two common stereo camera capture setups: "toein" and "off-axis" (we present their mathematical description). We show several morphed disparity map examples for each disparity manipulation method. Finally, we describe disparity-based image rendering to synthesize new stereo image pairs from given original stereo image pairs based on a morphed disparity map. The synthesis method includes image warping, data-filling and disparity map smoothing procedures.
Study of a viewer tracking system with multiview 3D display
Jinn-Cherng Yang, Chang-Shuo Wu, Chuan-Heng Hsiao, et al.
An autostereoscopic display provides users great enjoyment of stereo visualization without uncomfortable and inconvenient drawbacks of wearing stereo glasses. However, bandwidth constraints of current multi-view 3D display severely restrict the number of views that can be simultaneously displayed without degrading resolution or increasing display cost unacceptably. An alternative to multiple view presentation is that the position of observer can be measured by using viewer-tracking sensor. It is a very important module of the viewer-tracking component for fluently rendering and accurately projecting the stereo video. In order to render stereo content with respect to user's view points and to optically project the content onto the left and right eyes of the user accurately, the real-time viewer tracking technique that allows the user to move around freely when watching the autostereoscopic display is developed in this study. It comprises the face detection by using multiple eigenspaces of various lighting conditions, fast block matching for tracking four motion parameters of the user's face region. The Edge Orientation Histogram (EOH) on Real AdaBoost to improve the performance of original AdaBoost algorithm is also applied in this study. The AdaBoost algorithm using Haar feature in OpenCV library developed by Intel to detect human face and enhance the accuracy performance with rotating image. The frame rate of viewer tracking process can achieve up to 15 Hz. Since performance of the viewer tracking autostereoscopic display is still influenced under variant environmental conditions, the accuracy, robustness and efficiency of the viewer-tracking system are evaluated in this study.
Ghosting reduction method for color anaglyphs
Anaglyph is the simplest and the most economical method for 3D visualization. However, anaglyph has several drawbacks such as loss of color or visual discomfort, e.g., region merging and the ghosting effect. In particular, the ghosting effect, which is caused by green penetrating to the left eye, brings on a slight headache, dizziness and vertigo. Therefore, ghosting effects have to be reduced to improve the visual quality and make viewing of the anaglyph comfortable. Since red lightness is increased by penetration by green, the lightness of the red band has to be compensated for. In this paper, a simple deghosting method is proposed using the red lightness difference of the left and right images. We detected a ghosting area with the criterion, which was calculated from the statistics of the difference image, and then the red lightness of the anaglyph was changed to be brighter or darker according to the degree of the difference. The amount of change of red lightness was determined empirically. These adjustments simultaneously reduced the ghosting effect and preserved the color lightness within the non-ghosting area. The proposed deghosting method works well, and the goal of this paper was to detect the ghosting area automatically and to reduce the ghosting.
A method of fabricating micro-retarder plates by a laser system
Langchin Lin, Ying-Chi Chen, Chao-Hsu Tsai, et al.
Different fabrication methods, such as chemical process, laser heating method, etc., can be used to make micro-retarder plates. In this paper, a CO2 laser scanning system is applied to produce a serious of line patterns on the commercial compensator (or the retarder film, such as PC film, PVA film, or Arton film, etc.) to make micro-retarder plates, which are important optical components in stereoscopic 3D displays. Our study is focused on the development of high quality fabrication method, for example, the relationship of a well-defined stripe boundary with the CO2 laser process under single beam or multiple beams. The laser scanning system in this paper is installed with an orthogonal pair of precise translation stages, a steadily controlled laser power output, and an adjustable spot-size optical head to make patterns of micro-retarder plates for stereo-LCTVs up to 42 inches.
Extraction of digital elevation map from parallel-perspective stereo mosaics
Prudhvi Gurram, Eli Saber, Harvey Rhody
In this paper we present an algorithm to extract the Digital Elevation Map or Model (DEM) of a scene from a pair of parallel-perspective stereo mosaics. Stereo mosaics are built from an aerial video of a scene using parallel ray interpolation technique. In addition to the left and right stereo pair, we also build a mosaic along the nadir view to distinguish between the apparent visible and occluded surfaces. This distinction helps us in fitting vertical planes to the occluded surfaces (in nadir view) and developing a complete CAD model of each object (especially buildings in an urban scene). Buildings and trees are two important classes of objects observed in urban scenes. So, the nadir mosaic is segmented and building/tree regions (segments) are identified and separated from terrain. The edges and corners of different surfaces of a building are identified. We match the control points along these edges to their corresponding points in left and right mosaic. Using the disparity between the corresponding points in the mosaics, an elevation map is developed at these points. Optimal surfaces are fit to each of the segments through the edge points. Parts of a DEM of a scene like buildings extracted from a real airborne video are presented in this paper.
Robust image, depth, and occlusion generation from uncalibrated stereo
B. Barenbrug, R-P. M. Berretty, R. Klein Gunnewiek
Philips is developing a product line of multi-view auto-stereoscopic 3D displays.1 For interfacing, the image-plus-depth format is used.2, 3 Being independent of specific display properties, such as number of views, view mapping on pixel grid, etc., this interface format allows optimal multi-view visualisation of content from many different sources, while maintaining interoperability between display types. A vastly growing number of productions from the entertainment industry are aiming at 3D movie theatres. These productions use a two view format, primarily intended for eye-wear assisted viewing. It has been shown4 how to convert these sequences into the image-plus-depth format. This results in a single layer depth profile, lacking information about areas that are occluded and can be revealed by the stereoscopic parallax. Recently, it has been shown how to compute for intermediate views for a stereo pair.4, 5 Unfortunately, these approaches are not compatible to the image-plus-depth format, which might hamper the applicability for broadcast 3D television.3
Integral photography using hexagonal fly's eye lens and fractional view
We have developed a new integral photography (IP) system that incorporates a hexagonal fly's eye lens sheet to create a fractional view. In a fractional view, the ratio between the lens and pixel pitches of the IP image is intentionally chosen to be a non-integer so that the directions of all the rays emitted from each pixel on the LCD panel located behind the sheet become quasi-random. Creating a fractional view simultaneously increases the effective number of individual views and the resolution of each view. Furthermore, initial production costs can be decreased because the fractional view can be created using inexpensive off-the-shelf lens sheets together with a variety of common flat panel displays that have different pixel pitches. The difference in pitch is compensated for using computer software. The problem is that fractional views were originally only used with lenticular-lens based displays that have a horizontal parallax; therefore, some extension is necessary if fractional views are to be used with displays that have a full parallax. Furthermore, a typical flat panel display, such as an LCD, consists of RGB subpixels that are in positions that are slightly shifted relative to each other. We have developed a way of extending existing fractional views in order to cope with the full parallax obtained by a fly's eye lens sheet and the pixel shift. We demonstrated that good binocular vision can be obtained when using two hexagonal fly's eye lens sheets that were made without any relation to an LCD.
Integral imaging with reduced color moire pattern by using a slanted lens array
Yunhee Kim, Gilbae Park, Seong-Woo Cho, et al.
In this paper, we propose a color moire pattern reduction method in integral three-dimensional imaging by slanting the lens array. The color moire patterns are examined as varying the slanted angles between the lens array and the display panel for choosing the angles for which the pattern is reduced. However, it is difficult to expect the tendency of the pattern. We simulate the color moire pattern on the assumption of ray optics and find out the angle where the moiré is reduced. With the proposed technique clear three dimensional images can be displayed. The explanation of the proposed method will be provided, and the simulation results will be shown. Finally, experimental results will verify the proposed method.
Flatbed-type omnidirectional three-dimensional display system using holographic lens array
Hideya Takahashi, Manabu Chikayama, Kenji Yamada
We propose an omnidirectional three-dimensional (3D) display system for multiple users as an improved version of our previous thin natural 3D display based on the ray reconstruction method. This is a tool for communication around a 3D image among a small number of people. It is a flatbed-type autostereoscopic 3D display system. It consists of some flat panel displays and some holographic lens array sheets. Its notable feature is the ability to display natural 3D images which are visible to multiple viewers at the same time. Moreover, 3D real images float over the proposed flatbed-type display. Thus, proposed display allows two or more people surrounding it to simultaneously observe floating 3D images from their own viewpoints. The prototype display consists of two DMD (digital micromirror device) projectors and two holographic lens array sheets. The number of the 3D pixels about one holographic lens array sheet is 48×96. Reconstructed 3D images are superimposed over the display. Therefore, this can display a floating 3D image which size is 108 mm ×80.8 mm ×80.8 mm. This paper describes a flatbed-type omnidirectional 3D display system, and also describes the experimental results.
Stereoscopic see-through retinal projection head-mounted display
Hideya Takahashi, Shun Hirooka
See-through head-mounted displays (HMDs) provide an effective capability for Mixed Reality. Some conventional monocular see-through HMDs have been developed and they can display two-dimensional virtual information. However, when two-dimensional virtual information is displayed, observers can understand it although it has no relation to real-world objects. What an observer sees needs to be augmented by virtual information in accordance with the real object. Such environments are provided by a stereoscopic see-through HMD. Though, this method has generally the drawback of dissociation between accommodation and convergence. In order to overcome this problem, we propose a new stereoscopic see-through HMD by using the principle of the modified Maxwellian View which solves the problem of the narrow viewing area. This HMD has an extremely long focal depth, and provides natural concordant accommodation and convergence. The proposed HMD consists of two pairs of an HOE and an LCD. An HOE is used as a combiner and a condenser lens which performs the Maxwellian View, and virtual 3D images can be displayed at any distance from viewer. We have verified that the accommodation consistent with the convergence by using proposed HMD. This paper describes the principle of the proposed stereoscopic see-through retinal projection HMD and also describes the experimental results.
3D display using motion parallax for long-depth expression
Kazutake Uehira, Masahiro Suzuki
We describe a 3-D display that can express differences between depths at extended distances of over tens of meters using an optical system consisting of a compact LCD, convex lens, and beam splitter for car-navigation applications. It uses motion parallax to perceive depth because binocular parallax does not work at long distances. In motion parallax, when an observer is moving toward an object, the rate at which the size of the image is expanded on his or her retina over time depends on the depth of the object. Therefore, the perceived depth of the image is expected to be controlled by changing the rate at which its size is expanded, irrespective of its real depth. The results of a subjective test using a moving car in which observers viewed an expanding test pattern seen ahead through its windshield demonstrated that the perceived depth could be changed by changing the rate at which the test pattern was expanded and this agreed well with the theoretically expected depth over 30 km/h or at 40 m depth. Consequently, we demonstrated that our 3-D display could express differences between depths at extended distances to meet the requirements for car-navigation applications.
Interactive tools for image-based stereoscopic artwork
Efstathios Stavrakis, Margrit Gelautz
In this paper we describe a set of interactive tools that we have built as an extension to our image-based stereoscopic non-photorealistic rendering system. The base system is capable of automatically turning stereoscopic input images to stereoscopic pictures that resemble artwork, including concept drawings, cartoons and paintings. The tools described here aim to complement the traditional stereoscopic viewing experience of the end-user by enabling him to interact with the perceived stereoscopic space. The observers of the generated artwork can easily enhance the perceived depth by manipulating the two artistic-looking projections while stereo viewing. The users can examine the stereoscopic artwork via the use of stereoscopic cursors, as well as explore the structure of multi-layered artwork by peeling away layers at different depths to reveal other layers, initially occluded.
Toward a stereoscopic encoder/decoder for digital cinema
Rafik Bensalma, Mohamed-Chaker Larabi
The digital cinema is very challenging because it represents tomorrow way of capturing, post-producing and projecting movies. Specifications on this media are provided by DCI (Digital Cinema Initiatives) founded by the Hollywood Majors. Among the specifications we can find issues about resolution, bitrate, JPEG2000 compression Moreover, the market assumes that 3D could raise the turnover of cinema industry. The problem with is the availability of 2 streams (left and right) that double the amount of data and need adapted devices to decode and project movies. Cinema industry, represented by the stereoscopic group in SMPTE has expressed the need of having a unique master that combines two streams in one. This paper focuses on the study of the generation of a master with one of the streams and the embedment of the redundant information as metadata in JPEG2000 code-stream or MXF. The idea is to use the reference image in addition to some metadata to reconstruct the target image. The metadata represent the residual image and the contours description. Quality of reconstructed images depends on the compression ratio of the residual image. The obtained results are encouraging and the choice between JPEG2000 metadata embedding and MXF metadata still to be done.