Vision and hearing are inherently, different perceptual systems. The vision system is tuned to extract spatial information of surfaces and edges, while the auditory system is better suited to detect the temporal behav...
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ISBN:
(纸本)0769515215;0769515223
Vision and hearing are inherently, different perceptual systems. The vision system is tuned to extract spatial information of surfaces and edges, while the auditory system is better suited to detect the temporal behavior of sources. However, there are spatial audio effects that can be used to overcome some limitations of visual displays, especially when time-varying complex scenarios have to be rendered, and when the visual display devices are limited in size and complexity. We will review some spatial sound effects and give hints for applications in information visualization.
Recent developments in 3d technologies and measurement instrumentation combined with multimedia databases offer today new possibilities for the integrated and complete description of Cultural Heritage objects. A first...
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ISBN:
(纸本)0769515223
Recent developments in 3d technologies and measurement instrumentation combined with multimedia databases offer today new possibilities for the integrated and complete description of Cultural Heritage objects. A first attempt is made to develop a database for archaeological ceramic and glass artifacts where in addition to the digitized 2d and3d images, description, typological characteristics and historical information for each artifact will also include point-wise surface data. In a pilot implementation, physicochemical data mapped on the surface of the 3ddigital image of the object will be included. Thus, the researcher will have the entire information regarding the specific artifact at his disposal. This information will contribute significantly, to the comparative study of artifacts, provenance studies, determination of weathering, authentication anddetection of forgery, inspection of past restorations etc.
As products of second-order computations, estimations of principal curvatures are highly sensitive to noise. due to the availability of more accurate 3d range imaging equipment, evaluation of existing algorithms for t...
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ISBN:
(纸本)0769515215;0769515223
As products of second-order computations, estimations of principal curvatures are highly sensitive to noise. due to the availability of more accurate 3d range imaging equipment, evaluation of existing algorithms for the extraction of these invariants and other useful features from discrete 3ddata, is now relevant. The work presented here, makes some subtle but very important modifications to two such algorithms, originally suggested by Taubin [14] and Chen and Schmitt [2]. The algorithms have been adjusted to deal with real discrete noisy range data. The results of this implementation were evaluated in a series of tests on synthetic and real input yielding reliable estimations. Our conclusion is that with current scanning technology and the algorithms presented here, reliable estimates of the principal curvatures and the darboux frame can be extracted from real data and used in a variety of more comprehensive tasks.
This paper presents a computer vision stereo based interface to navigate inside a 3-d Internet city, using bode, gestures. A wide-baseline stereo pair of cameras is used to obtain 3-d body, models of the user39;s ha...
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ISBN:
(纸本)0769515223
This paper presents a computer vision stereo based interface to navigate inside a 3-d Internet city, using bode, gestures. A wide-baseline stereo pair of cameras is used to obtain 3-d body, models of the user's hands and head in a small desk-area environment. The interface feeds this information to an HMM gesture classifier to reliably recognize the user's browsing commands. To illustrate the features of this interface we describe its application to our 3-d Internet browser which facilitates the recollection of information by organizing and embedding it inside a virtual city through which the user navigates.
In this paper we present a three-dimensional model retrieval system. In our approach, a three-dimensional model is described by, three invariant descriptors: a curvature index which consists of a histogram of the prin...
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ISBN:
(纸本)0769515215;0769515223
In this paper we present a three-dimensional model retrieval system. In our approach, a three-dimensional model is described by, three invariant descriptors: a curvature index which consists of a histogram of the principal curvatures of each face of the mesh, a histogram of distances between the faces, and a histogram of the volumes based on each face. This work focuses on extracting these invariant descriptors from the three-dimensional models, and on combining these descriptors in order to improve retrieval performance. An experimental evaluation demonstrates the satisfactory performance of our approach on a fifty, three dimensional models database.
3d video is the ultimate image medium recording dynamic visual events in the real world as is. Recorded object behaviors can be observed from any viewpoint, because 3d video records the object39;s full 3d shape, mot...
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ISBN:
(纸本)0769515215;0769515223
3d video is the ultimate image medium recording dynamic visual events in the real world as is. Recorded object behaviors can be observed from any viewpoint, because 3d video records the object's full 3d shape, motion, and precise surface properties (i.e. color and texture). In our last paper[1], we presented a method of reconstructing dynamic 3d object shape from multi-view video images, by which a temporal series of 3d voxel representations of the object behavior can be obtained in real-time. In this paper following an overview of the real-time 3d shape reconstruction method, we present 1) an algorithm of generating texture on the 3d object surface from the multi-view video images, and 2) an editing system for visualizing 3d video with an omnidirectional background image using versatile 3d camera works. This paper mainly discusses how we can generate high fidelity object images from arbitrary viewpoints based on the 3d object shape of limited accuracy. We propose a novel texture mapping algorithm which maps textures onto the 3d object surface depending on a viewpoint. Experimental results demonstrate its effectiveness in generating high fidelity object images from arbitrary viewpoints.
View-based3d video streaming requires the compression andtransmission of depth maps along with the video sequence. The requirements for representing these depth maps include moderately, high compression, preservatio...
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ISBN:
(纸本)0769515215;0769515223
View-based3d video streaming requires the compression andtransmission of depth maps along with the video sequence. The requirements for representing these depth maps include moderately, high compression, preservation of depth discontinuities, low complexity decoding, and to be in a form that is suitable for real-time rendering using graphics cards. This motivates a mesh-based representation for the depth map. We adapt a mesh generation algorithm used in real-time height field rendering for depth map representation and produce a regular mesh for each depth map. Then we propose a compression technique that encodes the triangulateddepth map as a set of single bit enabled flags that mark the split of triangles, anddepth values at the vertices with Huffman code. By coding the vertices in the rendering order, we achieve depth map decoding and striped triangles for OpenGL based rendering in one loop, thus greatly, reducing the complexity, at the rendering end.
Ultrasound imaging is a helpful aid for diagnosis in many medical specialities. In order to enhance the information available to the examiner, an upcoming approach is to compound the sequence of video images into a si...
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ISBN:
(纸本)0769515223
Ultrasound imaging is a helpful aid for diagnosis in many medical specialities. In order to enhance the information available to the examiner, an upcoming approach is to compound the sequence of video images into a single 3d volume, which needs a real-time tracking of the transducer However, errors in the positioning occur and the compounded image becomes degraded. We propose a method which automatically corrects the positioning error by, means of a registration step between the live ecography and the compounded volume. The algorithm has been tested on sequences taken on an in-vitro human brain.
We describe an algorithm for detecting automatically relevant features in 2d color images of either frontal or rotated human faces. Such features allow to initialize robustly algorithms which fit a generic 3d face mod...
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ISBN:
(纸本)0769515215;0769515223
We describe an algorithm for detecting automatically relevant features in 2d color images of either frontal or rotated human faces. Such features allow to initialize robustly algorithms which fit a generic 3d face model to the images. The algorithm first identifies the sub-images containing each feature (eyes, nose and lips), afterwards, it processes them separately to extract fiducial points. The features are looked for in down-sampled images, the fiducial points are identified in the high-resolution ones. The method uses both color and shape information anddoes not require any manual setting or operator intervention. It has been tested on a database of 130 color images.
The aim of this study is to present researches made in a 3d scanner conception of hum-an foot. The first step of foot reconstruction is treated. The cloud number points is increased thanks to a combination of several ...
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ISBN:
(纸本)0769515215;0769515223
The aim of this study is to present researches made in a 3d scanner conception of hum-an foot. The first step of foot reconstruction is treated. The cloud number points is increased thanks to a combination of several methods. The first method for the first points extraction is explained. The relative length, height and width of the object are obtained in order to construct the parallelepiped including the foot. All parallelepiped points are virtually assigned to foot points. Each image are projected in the volume in the different planes of the views in order to eliminate the exterior points. From the volume of all these points only the points of the surface are retained. The points of the cloud should be located on or out surface foot. This reconstruction must be ameliorated by an active triangulation. We will use the tools of matching points of stereovision in the images profiles.
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