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.
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, 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.
Three-dimensional surface reconstruction from two-dimensional images is a process with great potential for use on different fields of research, commerce and industrial production. In this article we will describe the ...
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ISBN:
(纸本)0769515223
Three-dimensional surface reconstruction from two-dimensional images is a process with great potential for use on different fields of research, commerce and industrial production. In this article we will describe the evolution of a project comprising the study anddevelopment of systems which implement the aforementioned process, exploring several techniques with the final aim of devising the best possible compromise between flexibility, performance and cost-effectiveness. We will firstly focus our attention on past work, namely the description of the implementation and results of a fixed system involving a camera and a laser-stripe projector mounted on a pan-tilt unit which sweeps the surface vertically with a horizontal stripe. Then we will describe our current work on the development of a fully portable, handheld system using cameras, projected structured light and inertial/magnetic positioning and attitude sensors - the Tele-3d scanner.
Construction of large-scale virtual environment is gaining more attentions for its applications in virtual mall, virtual sightseeing, tele-presence, etc. We introduce a framework to construct realistic large-scale vir...
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ISBN:
(纸本)0769515223
Construction of large-scale virtual environment is gaining more attentions for its applications in virtual mall, virtual sightseeing, tele-presence, etc. We introduce a framework to construct realistic large-scale virtual environment by fusing range data, texture images, and airborne altimetry data. First, realistic and high-precision 3-d models of buildings are created from range data and texture images. Next, rough 3-d models of buildings in wide area are created using altimetry data acquired by airborne laser profiler Finally, these models are integrated to build a large-scale realistic walk-through system. This paper describes the proposed system, part of its implementations, as well as future works that still have to be done.
One of the main problems of 3d imaging in optical microscopy is unisotropic optical resolution of acquired3ddata. For instance in confocal laser scanning microscopy, axial resolution is 2-3 times worse than the late...
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ISBN:
(纸本)0769515215;0769515223
One of the main problems of 3d imaging in optical microscopy is unisotropic optical resolution of acquired3ddata. For instance in confocal laser scanning microscopy, axial resolution is 2-3 times worse than the lateral one. A sophisticated solution of this problem is so-called micro axial tomography that provides a good means for microscopic image acquisition of cells or subcellular components like cell nuclei with an improved resolution achieved by object tilting and acquisition of a series of mutually tilted3d image data. Since the very early developments of micro axial tomography a considerable drawback of this method was a complicated image acquisition andprocessing procedure that requires much operator time. In order to solve this problem advanced microscopy and automated computer image acquisition and analysis were brought together. Special software that drives all hardware components required for automated micro axial tomography was developed. It performs multi-view 3d image acquisition as well as related image processing.
We present a hierarchical and robust algorithm addressing the problem of filtering and segmentation of three-dimensional acoustic images. This algorithm is based on the tensor voting approach - a unified computational...
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ISBN:
(纸本)0769515223
We present a hierarchical and robust algorithm addressing the problem of filtering and segmentation of three-dimensional acoustic images. This algorithm is based on the tensor voting approach - a unified computational framework for the inference of multiple salient structures. Unlike most previous approaches, no models or prior information of the underwater environment, nor the intensity information of acoustic images is considered in this algorithm. Salient structures and outlier noisy points are directly clustered in two steps according to both the density and the structural information of input data. Our experimental trials show promising results, very robust despite the low computational complexion.
In spite of an undoubted richness of information produced by 3d optical technologies, in some cases, the method for generating a digital model from single 3d acquisitions involves the propagation of errors. These erro...
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ISBN:
(纸本)0769515215;0769515223
In spite of an undoubted richness of information produced by 3d optical technologies, in some cases, the method for generating a digital model from single 3d acquisitions involves the propagation of errors. These errors limit the overall metric accuracy attainable with such procedure. This happens when small 3d images are assembled together in order to model a large object. The authors present a procedure by which the metric reliability of the 3d model, obtained through iterative alignments of single range maps, can be guaranteed to an acceptable level. For this purpose, non-impeding optical targets were specifically designed for placement around the object. These are measured using a close range digital photogrammetry technique and by the 3d range camera system. From these measurements, transformation matrices have been calculated. Each matrix allows for the roto-translation (pose) of the 3d images from the local coordinate system of the range camera to an accurate global coordinate system determined by the digital photogrammetric procedure.
We propose a novel method to study storage system predictability based on the visualization of file successor entropy, a form of conditional entropy drawn from a file access trace. First-order conditional entropy can ...
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ISBN:
(纸本)0769515215;0769515223
We propose a novel method to study storage system predictability based on the visualization of file successor entropy, a form of conditional entropy drawn from a file access trace. First-order conditional entropy can be used as a measure of predictability. It is superior to the more common measures such as independent likelihood of data access. For file access data, we developed a visualization tool that produces 3d graphical views of the variation in predictability of successive access events on a per-file basis. Our visualization tool provides interactive observation of the variations in predictability according to some arbitrary criterion, e.g. time of day, program identifier, user groups, or an), other classification of files. Four entropy data sets were extracted from various file system traces. These four data sets are representative of the variability in file access patterns for different machine use: server personal workstation, large number of interactive users, and heavy write activity. visualization results show that there is strong predictability among files and optimizations would be profitable.
In this paper two disparity estimators with different complexity degrees are described and used to examine how much disparity inaccuracies influence image rendering quality. The objective of this study is to design so...
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ISBN:
(纸本)0769515223
In this paper two disparity estimators with different complexity degrees are described and used to examine how much disparity inaccuracies influence image rendering quality. The objective of this study is to design software-based image synthesis in real-time on conventional PC platforms. Basically, this work looks at the opposite end of the cost-complexity curve by making very restraineddemands to the disparity estimator. It is empirically shown that in many cases the effect of disparity accuracy in the quality of virtual views is almost imperceptible and that for many applications requiring real-time processing reasonable good results can be achieved with less computational cost.
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