Specular reflections and inter-reflections produce strong highlights in brightness images. These highlights can cause vision algorithms, such as, segmentation, shape from shading, binocular stereo, and motion detectio...
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ISBN:
(纸本)0818638826
Specular reflections and inter-reflections produce strong highlights in brightness images. These highlights can cause vision algorithms, such as, segmentation, shape from shading, binocular stereo, and motion detection to produce erroneous results. We present an algorithm for separating the specular and diffuse components of reflection from images. The method uses color and polarization, simultaneously, to obtain strong constraints on the reflection components at each image point. Polarization is used to locally determine the color of the specular component, constraining the diffuse color at a pixel to a one dimensional linear subspace. This subspace is used to find neighboring pixels whose color is consistent with the pixel. Diffuse color information from consistent neighbors is used to determine the diffuse color of the pixel. In contrast to previous separation algorithms, the proposed method can handle highlights that have a varying diffuse component as well as highlights that include regions with different reflectance and material properties. We present several experimental results obtained by applying the algorithm to complex scenes with textured objects and strong inter-reflections.
This paper describes multi-scale relaxation labeling for segmentation of fractal images. The images used are of pavement distress, on which simple edge detection schemes perform poorly. We use relaxation labeling to i...
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ISBN:
(纸本)0818638826
This paper describes multi-scale relaxation labeling for segmentation of fractal images. The images used are of pavement distress, on which simple edge detection schemes perform poorly. We use relaxation labeling to improve upon initial edge-based segmentation. Earlier work has shown that pavement distress can be well-modeled by fractals;the scale-invariance property of fractals suggests that information at different scales of resolution may be combined to improve segmentation. Thus, we have developed a multi-scale relaxation technique for use in a pavement distress detection system. To better model pixel interactions, we have included non-linear terms in the relaxation process. Symmetry arguments and careful engineering allows a 99% reduction in the complexity of this *** demonstrate the necessity of the multiscale approach, examples with and without multi-scale relaxation are shown. We found that performance gets greatly improved by multi-scale relaxation.
Modeling nonrigid moving 3-D objects entails recovery of global motion, global shape, and local shape. The already difficult problem of tracking nonrigid local shape is made worse by the need for a model-data correspo...
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ISBN:
(纸本)0818638826
Modeling nonrigid moving 3-D objects entails recovery of global motion, global shape, and local shape. The already difficult problem of tracking nonrigid local shape is made worse by the need for a model-data correspondence scheme to make tracking possible. We address both the problems in this paper. Reliable model-data Correspondence is crucial for physically-based methods to derive external forces. We discuss various methods for establishing 3-D model-data correspondence, and present a correspondence scheme for tessellated data. We then present a force-based method for nonrigid motion tracking. Our method does not use complex finite element techniques but follows a residual force-based dynamic model for local deformation. Another novel feature of our method is that the net forces are obtained by an adaptive force distribution scheme which ensures smooth and stable deformation. We present results of tracking simulated as well as real 3-D data of the inner wall of the heart ventricle from segmented magnetic resonance images.
In this paper it is shown how false operator responses due to missing or uncertain data can be significantly reduced or eliminated. Perhaps the most well-known of such effects are the various `edge effects' which ...
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ISBN:
(纸本)0818638826
In this paper it is shown how false operator responses due to missing or uncertain data can be significantly reduced or eliminated. Perhaps the most well-known of such effects are the various `edge effects' which invariably occur at the edges of the input data set. Further, it is shown how operators having a higher degree of selectivity and higher tolerance against noise can be constructed using simple combinations of appropriately chosen convolutions. The theory is based on linear operations and is general in that it allows for both data and operators to be scalars, vectors or tensors of higher order. Three new methods are presented: Normalized convolution, Differential convolution and Normalized Differential convolution. All three methods are examples of the power of the signal/certainty - philosophy, i.e. the separation of both data and operator into a signal part and a certainty part. Missing data is simply handled by setting the certainty to zero. In the case of uncertain data, an estimate of the certainty must accompany the data. Localization or `windowing' of operators is done using an applicability function, the operator equivalent to certainty, not by changing the actual operator coefficients. Spatially or temporally limited operators are handled by setting the applicability function to zero outside the window. Consistent with the philosophy of this paper all algorithms produce a certainty estimate to be used if further processing.is needed. Spectrum analysis is discussed and examples of the performance of gradient, divergence and curl operators are given.
The use of a heterogeneous multiple-SIMD (M-SIMD) architecture with image-based measurements and optimal (Kalman) estimators for the analysis of image sequences is illustrated. The architecture integrates SIMD and MIM...
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An algorithm for extracting and segmenting surface descriptions from stereo images is presented. Compared with the advance of range image segmentation, the progress of surface segmentation from stereo images is slow. ...
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An approach to image feature extraction is proposed. Complex moments of the Gabor power spectrum are used to detect linear, rectangular, hexagonal/triangular, and other structures with very fine to very coarse resolut...
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A multichannel filtering-based texture segmentation method is applied to a variety of document imageprocessing.problems: text-graphics separation, address-block location, and bar code localization. In each of these s...
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The authors randomly sample appropriate range image points and solve equations determined by these points for the parameters of selected primitive type. From K samples they measure residual consensus to choose one set...
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The problem of motion recovery for a head-eye system from stereo image sequences is addressed. Two types of motions, the translation of the vehicle and the panning motion of the head, are considered. It is shown how t...
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