The Experts below are selected from a list of 163287 Experts worldwide ranked by ideXlab platform
David G. Kendall - One of the best experts on this subject based on the ideXlab platform.
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HOW TO LOOK AT OBJECTS IN A FIVE-Dimensional Shape SPACE: LOOKING AT GEODESICS
Advances in Applied Probability, 1995Co-Authors: David G. KendallAbstract:This paper is the third in a series with the general title 'How to look at the five-Dimensional Shape space E?,'- Parts I and II were concerned with distributions and diSusions respectively. Here we 'look at' geodesics.
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How to look at objects in a five-Dimensional Shape space: looking at geodesics
Advances in Applied Probability, 1995Co-Authors: David G. KendallAbstract:This paper is the third in a series with the general title ‘How to look at the five-Dimensional Shape space Σ4,3. Parts I and II were concerned with distributions and diffusions respectively. Here we ‘look at’ geodesics.
Song Zhang - One of the best experts on this subject based on the ideXlab platform.
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Uniaxial three-Dimensional Shape measurement with projector defocusing
Optical Engineering, 2012Co-Authors: Song ZhangAbstract:Our study shows that the phase error caused by improperly defocused binary structured patterns correlates to the depth z. This finding leads to a novel uniaxial three-Dimensional Shape measurement technique without triangulation. Since the measurement can be performed from the same viewing angle, this proposed method overcomes some limitations of the triangulation-based techniques, such as the problem of measuring deep holes. Our study explains the principle of the technique and presents some experimental results to verify its feasibility.
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Three-Dimensional Shape measurement using a structured light system with dual cameras
Optical Engineering, 2008Co-Authors: Song Zhang, Shing-tung YauAbstract:A structured light system for three-Dimensional Shape measurement with single camera has the shortcoming of camera occlusion. To alleviate this problem, this paper introduces a structured light system with dual cameras for three-Dimensional Shape measurement. We discuss (1) system description, (2) system calibration, (3) three-Dimensional data registration using the iterative closest-point (ICP) algorithm, and (4) three-Dimensional data merging using holoimage. The principle of the system is introduced, and experiments are presented to verify its performance.
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high speed three Dimensional Shape measurement system using a modified two plus one phase shifting algorithm
Optical Engineering, 2007Co-Authors: Song Zhang, Shing-tung YauAbstract:This paper describes a high-resolution, real-time, three- Dimensional Shape measurement system using the modified two-plus- one phase-shifting algorithm. The data acquisition speed is as high as 60 frames/s with an image resolution of 640480 pixels per frame. Ex- periments demonstrated that the system was able to acquire the dy- namic changing objects such as facial geometric Shape changes when the subject is speaking, and the modified two-plus-one phase-shifting algorithm can further alleviate the error due to motion. Applications of this system include manufacturing, online inspection, medical imaging, compute vision, and computer graphics. © 2007 Society of Photo-Optical Instru-
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high resolution real time three Dimensional Shape measurement
Optical Engineering, 2006Co-Authors: Song Zhang, Peise S HuangAbstract:We describe a high-resolution, real-time 3-D Shape measurement system based on a digital fringe projection and phase-shifting technique. It utilizes a single-chip digital light processing projector to project computer-generated fringe patterns onto the object, and a high-speed CCD camera synchronized with the projector to acquire the fringe images at a frame rate of 120 frames/s. A color CCD camera is also used to capture images for texture mapping. Based on a three-step phase-shifting technique, each frame of the 3-D Shape is reconstructed using three consecutive fringe images. Therefore the 3-D data acquisition speed of the system is 40 frames/s. With this system, together with the fast three-step phase-shifting algorithm and parallel processing software we developed, high-resolution, real-time 3-D Shape measurement is realized at a frame rate of up to 40 frames/s and a resolution of 532×500 points per frame.
Lionel C Gontard - One of the best experts on this subject based on the ideXlab platform.
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photogrammetry of the three Dimensional Shape and texture of a nanoscale particle using scanning electron microscopy and free software
Ultramicroscopy, 2016Co-Authors: Lionel C Gontard, Roland Schierholz, J Cintas, Rafal E DuninborkowskiAbstract:We apply photogrammetry in a scanning electron microscope (SEM) to study the three-Dimensional Shape and surface texture of a nanoscale LiTi2(PO4)3 particle. We highlight the fact that the technique can be applied non-invasively in any SEM using free software (freeware) and does not require special sample preparation. Three-Dimensional information is obtained in the form of a surface mesh, with the texture of the sample stored as a separate two-Dimensional image (referred to as a UV Map). The mesh can be used to measure parameters such as surface area, volume, moment of inertia and center of mass, while the UV map can be used to study the surface texture using conventional image processing techniques. We also illustrate the use of 3D printing to visualize the reconstructed model.
Andrey Pepelyshev - One of the best experts on this subject based on the ideXlab platform.
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Optimal designs for three-Dimensional Shape analysis with spherical harmonic descriptors
The Annals of Statistics, 2005Co-Authors: Holger Dette, Viatcheslav B. Melas, Andrey PepelyshevAbstract:We determine optimal designs for some regression models which are frequently used for describing three-Dimensional Shapes. These models are based on a Fourier expansion of a function defined on the unit sphere in terms of spherical harmonic basis functions. In particular, it is demonstrated that the uniform distribution on the sphere is optimal with respect to all Φ p criteria proposed by Kiefer in 1974 and also optimal with respect to a criterion which maximizes a p mean of the r smallest eigenvalues of the variance-covariance matrix. This criterion is related to principal component analysis, which is the common tool for analyzing this type of image data. Moreover, discrete designs on the sphere are derived, which yield the same information matrix in the spherical harmonic regression model as the uniform distribution and are therefore directly implementable in practice. It is demonstrated that the new designs are substantially more efficient than the commonly used designs in three-Dimensional Shape analysis.
Marc Schoenauer - One of the best experts on this subject based on the ideXlab platform.
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Artificial Evolution - Genetic Operators for Two-Dimensional Shape Optimization
Lecture Notes in Computer Science, 1996Co-Authors: Couro Kane, Marc SchoenauerAbstract:This paper presents a Genetic Algorithm approach to two-Dimensional Shape optimization. Shapes are represented as arrays of boolean pixels (material/void), or bit-arrays. The inadequacy of the (one-Dimensional) bitstring representation is emphasized, both a priori and experimentally. This leads to the design of crossover operators adapted to the two-Dimensional representation. Similarly, some non standard mutation operators are introduced and studied. A strategy involving evolutionary choice among these different operators is finally proposed. All experiments are performed on a simple test-problem of Optimum Design, as the computational cost of real-world problems forbids extensive experimental tests.