In this paper, we develop a novel method for camera calibration and correction. The novel method first employs a rigidity constraint from the rigid rotation matrix and the radial alignment constraint from the pin-hole...
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Streaming data to efficiently render complex 3d scenes in presence of global illumination is still a challenging task. In this paper, we introduce a new data structure based on a 3d grid of it-radiance vectors to stor...
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ISBN:
(纸本)9781605582139
Streaming data to efficiently render complex 3d scenes in presence of global illumination is still a challenging task. In this paper, we introduce a new data structure based on a 3d grid of it-radiance vectors to store the indirect illumination appearing on complex anddetailed objects: the Irradiance Vector Grid (IVG). This representation is independent of the geometric complexity and is suitable for quantization to different quantization schemes. Moreover, its streaming over network involves only a small overhead compared to detailed geometry, and can be achieved independently of the geometry. Furthermore, it can be efficiently rendered using modem graphics hardware. We demonstrate our new data structure in a new remote 3dvisualization system, that integrates indirect lighting streaming and progressive transmission of the geometry, and study the impact of different strategies on data transfer.
The development of shape repositories and3ddatabases rises the need of online visualization of 3d objects. The main issue with the remote visualization of large meshes is the transfer latency of the geometric inform...
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ISBN:
(纸本)9781605582139
The development of shape repositories and3ddatabases rises the need of online visualization of 3d objects. The main issue with the remote visualization of large meshes is the transfer latency of the geometric information. The remote viewer requires the transfer of all polygons before allowing object's manipulation. To avoid this latency problem, an approach is to send several levels of details of the same object so that lighter versions can be displayed sooner and replaced with more detailed version later on. This strategy requires more bandwidth, implies abruptly changes in object aspect as the geometry refines as well as a non negligible precomputing time. Since the appearance of a 3d model is more influenced by its normal field than its geometry, we propose a framework in which the object's LOd is replaced with a single simplified mesh with a LOd of appearance. By using Appearance Preserving Octree-Textures (APO), this appearance LOd is encoded in a unique texture, and the details are progressively downloaded when they are needed. Our APO-based framework achieves a nearly immediate object rendering while details are transmitted and smoothly added to the texture. Scenes keep a low geometry complexity while being displayed at interactive framerate with a maximum of visual details, leading to a better visual quality over bandwith ratio than pure geometric LOd schemes. Our implementation is platform independent, as it uses JOGL and runs on a simple web browser. Furthermore the framework doesn't require processing on the server side during the client rendering.
This article is going to describe our effort to build a Virtual Reality Center using several technologies such as 3d world model development, 3d sound generation, mutli-projector cylindrical display and3d image proce...
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ISBN:
(纸本)9789537044060
This article is going to describe our effort to build a Virtual Reality Center using several technologies such as 3d world model development, 3d sound generation, mutli-projector cylindrical display and3d image processing. The virtual reality center uses four data projector to project a large seamless picture to a hemi-cylindrical display from the back of screen. We use dolby digital Surround EX sound system with a 7.1 channel speaker. A software engine does any necessary transformation like intensity and edge blending and image warping to prepare input data for each projector. A stereo camera used to track the viewer who determines the directions with an Infra Red pointer. The camera produces a feedback for server to update the 3d world model. This virtual reality center can be used in different areas like as scientific visualization, industrial design, entertainment applications and training simulators.
In this paper, an approach is presented for terrain visualization on the Internet, in which the NURBS method is used for surface fitting conforming to the X3d standard. On the basis of centripetal and cross-sectional ...
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The article studies 3-d image of OCT reconstructing anddenoising method. Optical coherence tomography (OCT), which is a novel tomography method, is non-contact, noninvasive image of the vivo tomograms, and have chara...
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ISBN:
(纸本)9780819467652
The article studies 3-d image of OCT reconstructing anddenoising method. Optical coherence tomography (OCT), which is a novel tomography method, is non-contact, noninvasive image of the vivo tomograms, and have characteristic of high resolution and high speed;therefore it becomes an important direction of biomedicine imaging. However, when the OCT system using in vivo specimen, noise anddistortion are appeared, because the speed of the system was confined, therefore image needs the method of denoising and rebuilding. This paper studies the high scattering medium, such as specimen of skin, researches the filter and rebuilding algorithm. It proposes a novel dynamic average background estimation algorithms based on time-domain estimation method;then combining with filter in frequecy-domain avoid longitudinal direction distortion anddeep's amplitude distortion. By experement it compares anddiscusses result of above methods and shows this algorithms to improve the qualities of image. It uses gray and color index method, which is aim to increase visualization resolution, to implement pseudo-color coding in OCT ophthalmolgy image;uses iterative reconstruction to optimize algorithm, realizes OCT system data's 3-d reconstruction.
The article reports the interdisciplinary project of the virtualization of the Great Inscription of Gortyna (Crete) for 3ddocumentation, structural studies and physical replica purposes. The digitization of the longe...
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