The authors describe visual resolution characteristics of an array comprising many afocal optical units. It is shown by wave optics that light beams exiting the array will converge, forming a three- dimensional optical image. It is also clarified that the converging point and resolution are dependent on the angular magnification of the afocal unit. When the magnification is 1.0, the optical wave focuses on the converging point, and the resolution is dependent only on the diffraction of the afocal unit. If the magnification is not 1.0, the optical wave does not focus on the converging point, affecting the resolution as a result. Based on this, we have obtained viewing distances and object distances at which the effects on the resolution by diffraction or defocusing are not perceptible when an optical image formed by the array is viewed by an observer.

One of the main drawbacks on integral imaging systems is their limited depth of field. With the current state of sensor technology such limitation is imposed by the pixilated structure of cell detectors. So, depth of field only can be optimized by proper selection of system parameters. However, nowadays sensor technology experiments a fast development. As a result of it, it is sure that in a close future the number of pixels per elemental image will be high enough to not influence the system resolution. In this not-too-far context, new ideas should be applied to improve the depth of field of integral imaging systems. Here we propose a new method to significantly extend the depth of field. The technique is based on the combined benefits of a proper amplitude modulation of the microlenses, and the application of deconvolution tools.

Integral imaging attracts much attention as an autostereoscopic three-dimensional display technique for its many advantages. However, the disadvantage of integral imaging is that the expressible depth of three-dimensional image is limited and the image can be displayed only around the central depth plane. This paper proposes a depth- enhanced integral imaging with multiple central depth planes using multilayered display devices. Transparent display devices using liquid crystal are located in parallel to each other and incorporated into an integral imaging system in place of a conventional display device. As a result, the proposed method has multiple central depth planes and permits the limitation of expressible depth to be overcome. The principle of the proposed method is explained, and some experimental results are presented.

In this paper, we propose a software-based HD video transmission system that can deliver stereoscopic HD video securely over IP networks. To realize a flexible cost-effective system, processing components such as synchronized stereo multiplexing, network sending and receiving, corresponding de-multiplexing, and parallel decoding are all performed in software. To address the need for secure and confidential delivery, we also consider the security aspect of stereoscopic HD video transmission with low-complexity partial encryption. By adopting partial encryption scheme that protects selected important portion of HD video stream, we are balancing computational overhead and required security protection. Finally, based on a prototype implementation, we evaluate the feasibility and complexity of proposed system.

The term 'image quality' is often used to measure the performance of an imaging system. Recent research showed however that image quality may not be the most appropriate term to capture the evaluative processes associated with experiencing 3D images. The added value of depth in 3D images is clearly recognized when viewers judge image quality of unimpaired 3D images against their 2D counterparts. However, when viewers are asked to rate image quality of impaired 2D and 3D images, the image quality results for both 2D and 3D images are mainly determined by the introduced artefacts, and the addition of depth in the 3D images is hardly accounted for. In this experiment we applied and tested the more general evaluative concepts of 'naturalness' and 'viewing experience'. It was hypothesized that these concepts would better reflect the added value of depth in 3D images. Four scenes were used varying in dimension (2D and 3D) and noise level (6 levels of white gaussian noise). Results showed that both viewing experience and naturalness were rated higher in 3D than in 2D when the same noise level was applied. Thus, the added value of depth is clearly demonstrated when the concepts of viewing experience and naturalness are being evaluated. The added value of 3D over 2D, expressed in noise level, was 2 dB for viewing experience and 4 dB for naturalness, indicating that naturalness appears the more sensitive evaluative concept for demonstrating the psychological impact of 3D displays.

In this paper, the authors propose a novel method to construct a wide viewing two-dimension/three-dimension convertible system with two parallel display devices. With changing the role of each display device, it is possible to convert the display mode between 2D and 3D electrically without any mechanical movement. In 2D display mode, the rear display is used as a white light source and the front display device displays the 2D images. In 3D display mode, the rear display device and the lens array construct 3D images, while the front display device displays electrical masks to enhance the viewing angle of the 3D images. Since the basic principle for 2D and 3D display modes are the same as that of LCD display and integral imaging respectively, other improved techniques for both display modes, which will be accomplished with the progress in researches, can be easily applied to the system. The proposed method is also demonstrated by some experimental results.

In this paper, we present the characteristics of integral imaging systems with large depth when using plane illumination and diffusing illumination. For each system, we perform ray analysis based on ray optics. To check visual quality through optical experiments, we use an average image of observed images pickuped at various positions within large depth. Experimental results show that the use of diffusing illumination can improve visual quality of reconstruction 3-D images in large depth integral imaging system.

We can enlarge or reduce three-dimensional integral imaging images by using an optical multi-pickup method. We used the moving array- lenslet technique (MALT) to increase the spatial ray sampling rate of elemental images in the optical method. In this paper, we are proposing a digital magnification method to increase the spatial ray sampling rate without lens movement. The major drawback of the optical technique is the complexity due to the small lenslet movement. We used four popular two dimensional (2D) magnified interpolation methods, as: linear, cubic, spline and nearest. We compared the reconstructed integral imaging images using optical and digital magnification methods. When use the optical and digital magnification are used in a sequence, we can reduce the number of pickup procedures for the optical method to a forth while we can see almost the same resolution quality of the reconstructed integral imaging images.

Depth image based rendering (DIBR) is useful for multiview autostereoscopic systems because it can produce a set of new images with different camera viewpoints, based on a single two-dimensional (2D) image and its corresponding depth map. In this study we investigated the role of object boundaries in depth maps for DIBR. Using a standard subjective assessment method, we asked viewers to evaluate the depth and the image quality of stereoscopic images in which the view for the right eye was rendered using (a) full depth maps, (b) partial depth maps containing full depth information but that was only located at object boundaries and edges, and (c) partial depth maps containing binary depth information at object boundaries and edges. Results indicate that depth quality was enhanced and image quality was slightly reduced for all test conditions, compared to a reference condition consisting of 2D images. The present results confirm previous observations indicating that depth information at object boundaries is sufficient in DIBR to create new views such as to produce a stereoscopic effect. However, depth ratings for the partial depth maps tended to be slightly lower than those generated with the full depth maps. The present study also indicates that more research is needed to increase the depth and image quality of the rendered stereoscopic images based on DIBR before the technique can be of wide and practical use.

The standard procedure for diagnosing lung cancer involves two stages. First, the physician evaluates a high-resolution three-dimensional (3D) computed-tomography (CT) chest image to produce a procedure plan. Next, the physician performs bronchoscopy on the patient, which involves navigating the the bronchoscope through the airways to planned biopsy sites. Unfortunately, the physician has no link between the 3D CT image data and the live video stream provided during bronchoscopy. In addition, these data sources differ greatly in what they physically give, and no true 3D planning tools exist for planning and guiding procedures. This makes it difficult for the physician to translate a CT-based procedure plan to the video domain of the bronchoscope. Thus, the physician must essentially perform biopsy blindly, and the skill levels between different physicians differ greatly. We describe a system that enables direct 3D CT-based procedure planning and provides direct 3D guidance during bronchoscopy. 3D CT-based information on biopsy sites is provided interactively as the physician moves the bronchoscope. Moreover, graphical information through a live fusion of the 3D CT data and bronchoscopic video is provided during the procedure. This information is coupled with a series of computer-graphics tools to give the physician a greatly augmented reality of the patient's interior anatomy during a procedure. Through a series of controlled tests and studies with human lung-cancer patients, we have found that the system not only reduces the variation in skill level between different physicians, but also increases biopsy success rate.

Modern micro-CT scanners produce very large 3D digital images of arterial trees. A typical 3D micro-CT image can consist of several hundred megabytes of image data, with a voxel resolution on the order of ten microns. The analysis and subsequent visualization of such images poses a considerable challenge. We describe a computer-based system for analyzing and visualizing such large 3D data sets. The system, dubbed the Tree Analyzer, processes an image in four major stages. In the first two stages, a series of automated 3D image-processing operations are applied to an input 3D digital image to produce a raw arterial tree and several supplemental data structures describing the tree (central-axis structure, surface rendering polygonal data, quantitative description of all tree branches). Next, the human interacts with the system to visualize and correct potential defects in the extracted raw tree. A series of sophisticated 3D editing tools and automated operations are available for this step. Finally, the corrected tree can be visualized and manipulated for data mining, using a large number of graphics-based rendering tools, such as 3D stereo viewing, global and local surface rendering, sliding-thin slabs, multiplanar reformatted views, projection images, and an interactive tree map. Quantitative data can also be perused for the tree. Results are presented for 3D micro-CT images of the heart and liver.

This paper discusses three application areas for depth map creation using laser radar (LADAR); synthetic interocular distances (SIOD) and convergence, virtual set merging of live action and dynamic re-lighting of content in post. Any one of these applications brings considerable value to the video production process and each will be discussed in turn. Additionally, the problem of merging multiple LADAR views into an integrated model is discussed. Such large scale multi-view LADAR system are just now emerging and promise to create synthetic video environments more complex than dual cameras mixed with depth maps, resulting in the ability to adjust camera position via synthesis.

This paper proposes a novel multiple-image coding technique using Ray-Space interpolation. Ray-Space, an image-based rendering technique to generate arbitrary views from multiple cameras, describes three- dimensional space based on only ray information from a large number of cameras. Therefore, data compression is needed. We leverage the correlation of time and space aiming for high compression. H.264/AVC is employed for dynamic image coding, and studies have been conducted on using the AVC in time domain. Here we propose a novel algorithm that uses view-interpolation for coding in space domain. Interpolation is a method to generate the middle view in a stereoscopic setup. By generating interpolated images from coded images as reference ones, coding performance should give better results. Therefore, interpolation accuracy is important for coding performance. In this paper, we propose an interpolation technique using geometric information in a linear camera arrangement. By calculating the trace of each point considering camera arrangement, and obtaining its corresponding point, the middle image is generated. In so doing, the interpolation method is an intensity-based scheme, constrained by smoothness in disparity domain. Experiment of coding using interpolation outperforms the standard AVC by 1~2 dB in all bitrates. Moreover, we deal with occlusion regions by means of extrapolation using four images. To detect occlusion regions, we use two criteria, one is minimum error, second is ratio of minimum error between four images. In occlusion region, the intensity of middle image is generated using extrapolated images. This method gives up to 1~3 dB improvement compared to occlusion-ignored algorithm.

We propose a fast depth reconstruction algorithm for stereo sequences using camera geometry and disparity estimation. In disparity estimation process, we calculate dense background disparity fields in an initialization step so that only disparities of moving object regions are updated in the main process using real-time segmentation and hierarchical disparity estimation techniques. The estimated dense disparity fields are converted into depth information by camera geometry. Experimental results show that the proposed algorithm provides accurate depth information with an average processing speed of 15 frames/sec for 320x240 stereo sequences on a common PC. We also verified the performance of the proposed algorithm by applying it to real applications.

The next evolutionary step in enhancing video communication fidelity over wired and wireless networks is taken by adding scene depth. Three-dimensional video using integral imaging (II) based capture and display subsystems has shown promising results and is now in the early prototype stage. We have created a ray-tracing based interactive simulation environment to generate II video sequences as a way to assist in the development, evaluation and quick adoption of these new emerging techniques into the whole communication chain. A generic II description model is also proposed as the base for the simulation environment. This description model facilitate optically accurate II rendering using MegaPOV, a customized version of the open-source ray tracing package POV-Ray. By using MegaPOV as a rendering engine the simulation environment fully incorporate the scene description language of POV-Ray to exactly define a virtual scene. Generation and comparability of II video sequences adhering to different II-techniques is thereby greatly assisted, compared to experimental research. The initial development of the simulation environment is focused on generating and visualizing II source material adhering to the optical properties of different II- techniques published in the literature. Both temporally static as well as dynamic systems are considered. The simulation environment's potential for easy deployment of integral imaging video sequences adhering to different II-techniques is demonstrated.

Human visual attention system has a remarkable ability to interpret complex scenes with the ease and simplicity by selecting or focusing on a small region of visual field without scanning the whole images. In this paper, a novel selective visual attention model by using 3D image display system for a stereo pair of images is proposed. It is based on the feature integration theory and locates ROI(region of interest) or FOA(focus of attention). The disparity map obtained from a stereo pair of images is exploited as one of spatial visual features to form a set of topographic feature maps in our approach. Though the true human cognitive mechanism on the analysis and integration process might be different from our assumption the proposed attention system matches well with the results found by human observers.

Natural three-dimensional images can be produced by displaying a large number of directional images with directional rays. Directional images are orthographic projections of a three-dimensional object and are displayed with nearly parallel rays. We have already constructed 64-directional, 72-directional, and 128-directional natural three-dimensional displays whose angle sampling pitches of horizontal ray direction are 0.34°, 0,38°, and 0.25°, respectively. In this study we constructed a rotating camera system to capture 360° three-dimensional information of an actual object. An object is located at the center of rotation and a camera mounted at the end of an arm is rotated around an object. A large number of images are captured from different horizontal directions with a small rotation angle interval. Because captured images are perspective projections of an object, directional images are generated by interpolating the captured images. The 360° directional image consists of 1,059, 947, and 1,565 directional images corresponding to the three different displays. When the number of captured images is about ~ 4,000, the directional images can be generated without the image interpolation so that correct directional images are obtained. The degradation of the generated 360° directional image depending on the number of captured images is evaluated. The results show that the PSNR is higher than 35 dB when more than 400 images are captured. With the 360° directional image, the three-dimensional images can be interactively rotated on the three-dimensional display. The data sizes of the 360° directional images are 233 MB, 347 MB, and 344 MB, respectively. Because the directional images for adjacent horizontal directions are very similar, 360° directional image can be compressed using the conventional movie compression algorithms. We used H.264 CODEC and achieved the compression ratio 1.5 % with PSNR > 35 dB.

In microscopy, high magnifications are achievable for investigating micro-objects but the paradigm is that higher the required magnification, the lower the depth of focus. In this paper we show that it is possible to construct an extended focused image (EFI) image by a coherent optical microscope without any mechanical movement but by using the 3D imaging capability of digital holography (DH). In fact, DH has the unique property of allowing direct calculation and management of an amplitude and phase map along the longitudinal direction in front of the digital camera. That constitutes a fundamental feature of DH to construct an EFI image of an object or systems experiencing dynamic evolution since the recording of only one image is needed instead of performing a mechanical scanning and to record several images at different focus planes. In other words, by means of this approach it is possible to obtain an EFI image for studying dynamic objects, such as biological objects, dynamic MEMS.

We present a fast recording system of three-dimensional (3D) object based on phase-shifting digital holography. In this system, four-step phase shifting digital holography is employed. The phase modulation for four phase shifts is implemented by an electro-optic modulator that can change the phase of the reference at up to 100 MHz. The image detection is implemented by a C-MOS image sensor. We demonstrate experimentally the acquirement of 3D object information at 250 Hz. We also discuss the accuracy of the reconstructed position when the loss of the information at the image sensor is caused.

We report on recent advances made in the area of holographic image processing of three-dimensional (3D) objects. In particular, we look at developments made in the areas of encryption, compression, noise removal, and 3D shape extraction. Results are provided using simulated objects and real-world 3D objects captured using phase- shift digital holography.

The quasi one-shot phase-shifting digital holography using phase difference of orthogonal polarizations is proposed. The use of orthogonal polarizations can make it possible to record two phase-shifted holograms simultaneously. By combining the holograms with distributions of a reference wave and an object wave, the complex field of the wavefront of a 3D object can be obtained. As two phase-shifted holograms can be obtained simultaneously in the proposed method, even a moving object can be recorded.

Three-dimensional information about an object, such as its depth, may be captured and stored digitally in a single, two-dimensional, real- valued hologram acquired in an off-axis geometry. Digital reconstruction of the hologram permits the quantitative retrieval of depth data and object position, or allows post-acquisition focusing on selected scenes. Over the past few decades, a number of reconstruction algorithms have been proposed to perform this task in various experimental conditions and for different purposes (metrology, imaging, etc.). Here, we aim at providing guidelines for deciding which algorithm to apply to a given problem. We evaluate reconstruction procedures based on criteria such as reconstruction quality and computational complexity. We propose a simulation procedure of the acquisition process, that allows us to compare a large body of experimental situations and, because the ground truth is known, achieve quantitative comparison.

The methods of presenting multiview images, such as IP, the Multiview, Multiple Imaging and Focused light array are reviewed and their image forming principles were compared. These methods have their own ways of presenting multiview images but the images projected to viewer's eyes are mostly synthesized by the small part of each view image in the different view images presented to the viewers. This is a common property for all those methods.

De Montfort University, in conjunction with the Heinrich Hertz Institute, is developing a 3D display that is targeted specifically at the television market. It is capable of supplying 3D to several viewers who do not have to wear special glasses, and who are able to move freely over a room-sized area. The display consists of a single liquid crystal display that presents the same stereo pair to every viewer by employing spatial multiplexing. This presents a stereo pair on alternate pixel rows, with the conventional backlight replaced by novel steering optics controlled by the output of a head position tracker. Illumination is achieved using arrays of coaxial optical elements in conjunction with high-density white light emitting diode arrays. The operation of the steering and multiplexing optics in the prototype display are explained. The results obtained from a prototype built under the European Union-funded ATTEST 3D television project are described. The performance of this model was not optimum, but was sufficient to prove that the principle of operation is viable for a 3D television display. A second prototype, incorporating improvements based on experience gained, is currently under construction and this is also described. The prototype is capable of being developed into a display appropriate for a production model that will enable 3D television to come to market within the next ten years. With the current widespread usage of flat panel displays it is likely that customer preference will be for a hang-on-the-wall 3D display, and this challenge will be met by reconfiguring the optics and incorporating novel optical addressing techniques.

A multi-focus 3D display system is developed and tested the performance about supporting parallax image numbers within eye pupil diameter. The multi-focus means the ability of monocular depth cue to various depth levels. By achieving multi-focus function, we developed a 3D display system for only one eye, which can satisfy the accommodation to displayed virtual objects within defined depth. Therefore this proposed 3D display system has a possibility to solve the problem that the 3-dimensional image display system using only binocular disparity can induce the eye fatigue because of the mismatch between the accommodation of each eye and the convergence of two eyes. The accommodation of one eye is tested and a proof of the satisfaction of the accommodation is given as a result by using the proposed 3D display system. We could achieve a result that focus adjustment is possible at 5 step depths in sequence within 2m depth for only one eye. Additionally, the change level of burring depending on the focusing depth is tested by captured photos and moving pictures of video camera and several subjects.

We propose a 3D live video system that generates arbitrary viewpoints in real-time based on the ray-space, one of the image-based rendering. With this system, a remote user can freely change the viewpoint, not only according to the captured camera position, but also can synthesize views where a camera is not physical present using the ray-space interpolation. The basic idea of ray-space rendering is collecting and rearranging the partition of simultaneously captured images according to an arbitrarily specified virtual-view. If hundreds of cameras were arranged in significant density, synthesizing a free viewpoint away from the camera baseline require only camera geometric information. Since we cannot obtain such full information of ray according to plenoptic sampling, arbitrarily view generation necessitate interpolation of slightly missed rays. However, such view interpolation's cost is particularly huge. Therefore, we introduce three novel techniques of view interpolation: first, view centered interpolation framework, second, estimating disparity with smoothing, third, hierarchical searching of correspondences for fast computation. Moreover, we implement the experimental system with those algorithms. This free-view generating system includes sixteen cameras arranged straightforward. All cameras are connected with the consumer computers one by one. Whole the computers connect a server computer via Ethernet categorized star network. This system carries out four processes in real time: capture images, correct position of cameras with projective transformation, interpolate images on baseline, rendering arbitrary viewpoint. The experimental result shows that this system is rendering arbitrary viewpoint at 12fps (frames per second) set image resolution set to "320x240". We succeeded in synthesizing highly photo-realistic images.

An overview of 3D and free viewpoint video is given in this paper with special focus on related standardization activities in MPEG. Free viewpoint video allows the user to freely navigate within real world visual scenes, as known from virtual worlds in computer graphics. Suitable 3D scene representation formats are classified and the processing chain is explained. Examples are shown for image-based and model-based free viewpoint video systems, highlighting standards conform realization using MPEG-4. Then the principles of 3D video are introduced providing the user with a 3D depth impression of the observed scene. Example systems are described again focusing on their realization based on MPEG-4. Finally multi-view video coding is described as a key component for 3D and free viewpoint video systems. MPEG is currently working on a new standard for multi-view video coding. The conclusion is that the necessary technology including standard media formats for 3D and free viewpoint is available or will be available in the near future, and that there is a clear demand from industry and user side for such applications. 3DTV at home and free viewpoint video on DVD will be available soon, and will create huge new markets.

This paper describes issues and consideration on authoring of 3D visual content based on MPEG-4 Systems. The issues include types of 3D visual content; functionalities for user-interaction; 3D scene composition for rendering; and the 3D visual content file format. MPEG-4 includes several extensions compared to MPEG-1 and -2 especially in terms of object-based interactivity. In addition to advanced A/V compression methods (MPEG-4 Part2, Part3 and Part 10), MPEG-4 Part1, which is named "Systems", contains additional tools such as binary/textual file format, multiplexing, synchronization scheme, scene description, etc. The use of MPEG-4 can resolve the problem of format diversity while providing high interactivity to users. There has been little investigation on 3D visual content authoring. Throughout the paper, we will present which issues need to be determined and how currently available tools can be effectively utilized for 3D visual content creation.

The superimposing method for information reduction in hologram is compared with the sampling method to clarify their features. Visual field is divided in several fields for displaying visual depth of the image under reduced information, and partial images in divided visual fields are separately recorded on several Fourier transform holograms (FTHs). A time-sharing display system is developed to reconstruct the 3D image in real time from several FTHs. The 3D image with motion parallax is reproduced in the wide viewing zone from holograms with reduced information by reconstructing overlapped two images. Experiments are carried out for reconstruction of the practical 3D image from recorded holograms. Results show that resolution of the image is improved and the speckle noise is suppressed by the superimposing method. Depth of the 3D image can be perceived by viewing partial images reconstructed on Fourier transform planes. Observer can perceive motion parallax of the image by viewing a pair of overlapped stereoscopic images from right-eye and left-eye positions.

Recently many kinds of transmitting techniques have been developed, and a communicating network system with a very high transmission-rate has been constructed. Broad-band internet system may be one of the most useful communicating network systems. In this paper, a transmitting process of holographic 3D moving pictures accompanied by stereo sounds over the communicating network system is presented. It involves a transmitting technique of the hologram, in which holographic information of 3D moving pictures are recorded as fringe patterns. First, the information in the hologram is transformed into a bit stream data, and then it is transmitted over the internet system with stereo sound wave. We call it simply as "network streaming technique". It is shown that by an application of this technique, the holographic data of 3D moving pictures are transmitted in high quality, and relatively good reconstruction of holographic images are performed with nice stereo sounds. It suggests that based on "network streaming technique", a new transmitting process of holographic 3D moving pictures employed MPEG-4 and stereo sound wave can be rigorously developed, and it seems to play an important role in the transmission of 3D moving pictures accompanied by stereo sounds over the network.

We examine a method of digital holography to analyze three- dimensional (3D) scenes. We present a method for recognizing objects in 3D scenes using single exposure digital holography that can be used to detect the presence and position of a three-dimensional object within the scene as well as detect if it has an out of plane rotation. The use of a single hologram allows for a more practical implementation in real world applications such as those involving moving targets or those applications where noise is involved. Correlation methods are used to recognize the 3D reference object within the 3D scene and detect the position of that object.

We present a digital holographic microscope that has a wide field of view. Off-axis holograms are recorded with a magnified image of microscopic objects and numerically reconstructed by calculation of scalar diffraction in the Fresnel approximation. Holograms are recorded by CCD. The distance between neighbouring pixels of a CCD is only of the order of 5 micrometer. The corresponding maximum resolvable frequency is of the order of 100 linepairs /mm. The maximum angle between the reference and object wave is therefore limited to a few degrees. The higher magnification by an objective lens with the higher power makes the wider angle object beam. Off- axis holograms with the high power objective lens has the limitation of magnification and a field of view. We present a new type of imaging system that overcomes the limitation of magnification and a field of view. It is consisted of an objective lens and additional lens array. It makes the nearly same angle between object beams and a reference beam. The overlapped angles are also less than the maximum limited angle due to CCD pixel size. It also has a maximum field of view which is decided inherently by an objective lens. It therefore overcomes the limitation of the size of CCD.

A phase-shifting holography system for recording 3D color images is developed with a color CCD, and red (R), green (G), and blue (B) lasers. The phase of reference lights in this recording system is precisely shifted by changing fringe patterns displayed on a high-resolution reflective LCD panel. RGB interference fringe patterns are able to be recorded at the same time for a practical color object by adopting a high-resolution color CCD. Color images in the wide visual field are recorded by adopting a multi-channel CCD and are reconstructed from the recorded hologram by adopting a multi-channel LCD modulator. Holograms for reconstruction of RGB images are obtained from recorded fringe patterns by the phase-shifting holography, and fine color images with high quality are reconstructed from recorded phase-shifting holograms by using the developed holographic color display system. The visual field of the holographic system is enlarged by adopting a multi-channel color CCD for recording of the image and a multi-channel LCD panel for reconstruction of the image.

A time-sharing holographic color display system is developed using a high-resolution reflective liquid-crystal display (LCD) panel that consists of a 1920x1080 array of square pixels with width of 8.1 micron. Red, green and blue highresolution images are reconstructed from the holographic display system with a red laser diode (LCD), a green diodepumped laser and a blue diode-pumped laser. The reconstructed color images can clearly be observed under the room light. The images exhibit good color expression. High-quality color images of the practical object are reconstructed from the holograms by using the developed holographic display system. The viewing zone or the visual field of the holographic display is enlarged by adopting a multi-channel LCD modulator. 3-D full-color images are reconstructed in the wide visual field. Viewing zone angle or visual field angle of color images can be enlarged up to about 20 degrees by adopting a 6-channel LCD modulator.

We present a fusion method for multi-wavelengths holographic images using Discrete Wavelet transform (DWT). The advantage of DWT is more control on high as well as low frequencies to get better quality. Fusion results include monochromatic fused images and color fused images from holographic images reconstructed from holograms recorded with multiple wavelengths from 567nm to 613nm.

Stereoscopic conversion of two-dimensional (2-D) video is considered based upon image motions. In general, a stereoscopic camera with two imaging sensors is required for stereoscopic video, while the stereoscopic conversion directly converts 2-D video to 3-D stereoscopic video. Image motions that are needed to generate a stereoscopic image are computed by any motion estimation algorithms. However, it is well know that motion vectors are generally far from a true motion, thereby posing a difficulty in the utilization of such data. To overcome the aforementioned problem, each image frame is classified into either a primary frame (PF) or a secondary frame (SF) depending upon the reliability of motion vectors. Furthermore, the stereoscopic generation method of the PF is presented. For the performance evaluation of our proposed method, we apply it to five test sequences and measure the accuracy of our proposed method. Experimental results show that our proposed method has the accuracy more than about 90 percent in terms of the detection ratio of primary frames. Furthermore, a variety of test sequences encoded in MPEG are directly applied and support that our proposed method is well designed.

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

For large viewing-angle enhancement in three-dimensional (3D) display, a dynamic computer-generated holographic display system combined with integral imaging is proposed and implemented using a single phase-type spatial light modulator and an elemental lens array. For viewing-angle enhanced colorized 3D integral image display the computer-generated holograms have been synthesized and scaled for minimizing the color dispersion error in the hologram plane. Using the integral imaging and synthetic phase holography, we can get 3D images with full parallax and continuously varying viewing-angle range of +/-6 degree. Finally we show some experimental results that verify our concept.

A holographic imaging element (HIE) by use of a transmission-type holographic optical element is evaluated by a numerical simulator. To design HIE and evaluate its imaging characteristics, we fabricate a holographic imaging simulator between one-dimensional arbitrary spaces. In the simulator, two calculation methods that are free space propagation and diffraction at the holographic element are used. The propagated light between the input plane and a transmission-type HIE, or between the HIE and the observation plane is calculated by numerical Fresnel propagation. The diffracted light at the HIE is calculated by Kogelnik's coupled wave theory. By using the simulator, imaging characteristics of a pair of point sources and one- dimensional regions are evaluated.

As an approach for a 3D real image display system without special glasses, a Fresnel lens-based 3D rear-projection display system is implemented. In this display system, the conventional 2D video image is projected into the air through some projection optics, a screen and a pair of Fresnel lens and as a result, it can form a floating video image having a real depth. But in the conventional floating display system some image distortions might be occurred in the floating image plane, in which a flat screen has been mostly used for providing an adequate input image plane. In this paper, as a new approach to alleviate this image distortion problem, a Fresnel lens-based floating display system employing a curved screen is suggested and some computer simulations and practical experiments are carried out. That is, optimum design parameters of a curved screen for reducing image distortion is found out through some computer simulation using an optics design program of Light Tools and its performance in the floating system is experimentally verified and compared with those of the flat screen. Experimental results with a curved screen shows some decrease of image distortion in the floating image plane by comparing with that of the flat screen. This feasibility test suggests a possibility of implementation of a new Fresnel lens-based 3D projection display system with improved image distortion using a curved screen.