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An autostereoscopic imaging system, which displays moving actual images created from 2D video and depth data is proposed. The system consists of a depth camera, signal processing algorithms, and an integral display prototype. The specifications are as follows: (a) Depth camera: a monocular VGA video camera with optical distance sensor captures 2D texture image and its depth map simultaneously. (b) Signal processing: 10*10 parallax images are created from the video stream, and the angle between two neighboring parallax images is 0.8 degrees. (c) Display: The display device is contact type (LCD) or projection type (LCOS), and the optical device is a microlens-array. 2D resolution of the 3D image is 720 cycle/radian at a viewing distance and a viewing zone is about 8 degrees. Noticeable defects due to occlusions are not found within the viewing zone. The method of transmission of texture and depth data has higher compatibility with conventional coding technologies than transmission using compressed parallax images. And the transmission method enables the choice of various types of displays and how the contents are displayed. Therefore we believe that this system is a candidate for the future 3D television system.

In order to evaluate influence of electron beam (EB) irradiation on elasticity and stress- strain curve of composite materials reinforced by carbon fiber (CF), carbon fiber reinforced polymer (CFRP) and carbon fiber reinforced graphite (C/C) were treated by EB irradiation of 0.3 MGy. Since the EB strengthening was mainly dominated by the ductility enhancements of carbon fiber and matrix of epoxy resin, EB irradiation enlarged fracture stress and enhanced fracture strain of CFRP. Furthermore, EB irradiation slightly enhanced bending elasticity of CFRP and largely enhanced the initial spring constant related to elasticity of C/C coil. Although the elasticity enhancement of carbon fibers did not largely contribute that of CFRP, that of treated graphite matrix in C/C mainly caused the C/C coil elasticity enhancement by EB irradiation. Such a new treatment is a dream-worthy technology for structural materials to be applied in the fields of future engineering.

Effects of EB irradiation on fracture toughness were studied for soda lime glass and glass fiber. The EB irradiation improved the hardness, ductility, fracture stress and fracture toughness. The fracture stress was 1.43 GPa for the glass fiber before EB treatment. The irradiation enhanced the fracture stress. The fracture stress at P f =0.5 was 1.89 GPa for glass fiber samples treated by 65 Mrad-irradiation. It was approximately 0.46 GPa larger than that before EB treatment. Based on ESR results, the reinforcement can be explained. The changes in fracture stress were in good agreement with the density change in dangling bonds, because a high tensile glass fiber was obtained at 65 Mrad-irradiation. Thus, we confirmed that the glassy cluster structure with high dangling bond density was obtained in high tensile glass fibers prepared by 65 Mrad-irradiation. The EB irradiation controlled the fracture toughness of glasses. To confirm the mechanism, an alpha-aluminum oxide crystal sheet was also studied.

This paper proposes a technique to generate virtual views of a natural panorama scene. The scene is captured by an original 3-camera system. The images are stitched into a stereo panorama and the depth is estimated. The texture panorama is segmented into regions, each of which can be regarded to be approximated as a plane. The planar parameter set of the region for setting representation is calculated depending on the depth data. According to the representation the virtual views are generated using center panorama texture, and left and right panoramas are used for occlusion compensation.

Multimedia Ambiance Communication is as a means of achieving shared-space communication in an immersive environment consisting of an arch-type stereoscopic projection display. Our goal is to enable shared-space communication by creating a photo-realistic three-dimensional (3D) image space that users can feel a part of. The concept of a layered structure defined for painting, such as long-range, mid-range, and short-range views, can be applied to a 3D image space. New techniques, such as two-plane expression, high quality panorama image generation and setting representation for image processing, 3D image representation and generation for photo- realistic 3D image space have been developed. Also, we propose a life-like avatar within the 3D image space. To obtain the characteristics of user's body, a human subject is scanned using a CyberwareTM whole body scanner. The output from the scanner, a range image, is a good start for modeling the avatar's geometric shape. A generic human surface model is fitted to the range image. The obtained model is topologically equivalent even if our method is applied to another subject. If a generic model with motion definitions is employed, and common motion rules can be applied to all models made from the generic model.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A method for high quality stereo panorama mosaicing is presented. The surrounding scene is captured by our original 3-camera system as stereo moving picture sequences, and the images are stitched after improvement of the texture quality. The multi-purpose 3-camera system features accurate frame synchronization between 3 channels, and can be used outdoors through battery operation. For registration of panorama stitching, under the newly investigated distortion-free condition, Affine parameters are estimated through the overlapped areas by the steepest descent algorithm. The texture improvement has two steps, one is vertical resolution recovery by field integration, and the other is image enhancement by two dimensional quadratic Volterra filter which satisfies Weber-Fechner's law. The presented method enables high quality stereo mosaicing with accurate mutual disparities between the channels and without visible distortion of textures.

Multi-media Ambiance Project of TAO has been researching and developing an image space, that can be shared by people in different locations and can lend a real sense of presence. The image space is mainly based on photo-realistic texture, and some deformations which depend on human vision characteristics or pictorial expressions are being applied. We aim to accomplish shared-space communication by an immersive environment consisting of the image space stereoscopically projected on an arched screen. We refer to this scheme as 'ambiance communication.' The first half of this paper presents global descriptions on basic concepts of the project, the display system and the 3-camera image capturing system. And the latter half focuses on two methods to create a photo-realistic image space using the captured images of a natural environment. One is the divided expression of the long-range view and ground, which not only gives more realistic setting of the ground but commands more natural view when synthesized with other objects and gives potentialities of deformations for some purposes. The other is the high quality panorama generation based on even-odd field integration and image enhancement by a two dimensional quadratic Volterra filter.

This paper addresses a new scheme of acquisition of 3D image representation from range data and texture data. The concept of a layered structure defined for painting, such as long- range, mid-range, and short-range views, that can be applied to a 3D image. Long and mid-range views are located at a reasonable distance, and therefore do not require the perfect 3D structure. Instead of describing the perfect 3D structure, an image can be represented more simply with range information through a plane-model approximation. Setting representation can be used like stage setting to approximate objects and describe a 3D structure by plane- model. It is effective as a simplified means of describing 3D image space as in long and mid-range views that does not require a detailed 3D structure. We can obtain the parameters of plane shape from the integration of range data measured by a 3D laser scanner and a number of still images captured by a digital camera.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.