We examine the use of a multi-stage diffusion process in early processing.of range data. The input range data is interpreted as occupying a volume in 3-D space. Each diffusion stage simulates the process of diffusing ...
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ISBN:
(纸本)081863880X
We examine the use of a multi-stage diffusion process in early processing.of range data. The input range data is interpreted as occupying a volume in 3-D space. Each diffusion stage simulates the process of diffusing part of the boundary of the volume into the volume. The outcome of the process can be used for both discontinuity detection and segmentation into shape homogeneous regions. The process is applied to synthetic noise-free and noisy-step, roof, and valley edges, as well as real range images.
Previous approaches to separating transparently combined moving images have focused on the estimation of multiple velocities in a given image patch. This paper extends the definition of support from an exclusively spa...
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ISBN:
(纸本)081863880X
Previous approaches to separating transparently combined moving images have focused on the estimation of multiple velocities in a given image patch. This paper extends the definition of support from an exclusively spatial notion, to include the spatio-temporal energy domain. The key insight is that when processing.transparent motion displays, the support of a motion hypotheses should exist over both a region of space and velocity, so that it can be isolated both spatially and in terms of local velocity. With this formulation, two layers can have spatially overlapping support, but not be `conflicting' since they are distinct in the spatio-temporal energy domain.
Symmetry is usually viewed as a discrete feature;an object is either symmetric or non-symmetric. Following the view that symmetry is a continuous feature, a Continuous Symmetry Measure (CSM) has been developed to eval...
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ISBN:
(纸本)081863880X
Symmetry is usually viewed as a discrete feature;an object is either symmetric or non-symmetric. Following the view that symmetry is a continuous feature, a Continuous Symmetry Measure (CSM) has been developed to evaluate symmetries of shape and *** this paper we extend the symmetry measure to evaluate the symmetry of occluded shapes. Additionally, using the symmetry measure, we reconstruct occluded shapes by locating the center of symmetry of the shape.
The overall movement of articulated bodies (such as the human body) is enabled by the coordinated movement of its rigid body parts. The body parts are connected by joints and, in general, move differently. For, interp...
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ISBN:
(纸本)081863880X
The overall movement of articulated bodies (such as the human body) is enabled by the coordinated movement of its rigid body parts. The body parts are connected by joints and, in general, move differently. For, interpreting these movements as the movement of one single body, it seems to be necessary to incorporate knowledge in the analysis process. Therefore, in order to recognize pedestrians from monocular image sequences, we introduce a model-based approach. We represent the human body by a volume model and use medical motion data for simulating the movement of walking. This knowledge is exploited to determine the 3D-position as well as the posture of an observed person. By applying a Kalman filter we incrementally estimate the model parameters in consecutive images. Our approach has been tested on real image data.
Correspondence between pixels in two perspective views can be obtained from correspondence between surface patches. Establishing surface correspondence is formulated as a global minimization problem.
ISBN:
(纸本)0818638826
Correspondence between pixels in two perspective views can be obtained from correspondence between surface patches. Establishing surface correspondence is formulated as a global minimization problem.
Similarity measurements between 3D objects and 2D images are useful for the tasks of object recognition and classification. Existing systems typically use image metrics;namely, metrics that measure the difference in t...
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ISBN:
(纸本)081863880X
Similarity measurements between 3D objects and 2D images are useful for the tasks of object recognition and classification. Existing systems typically use image metrics;namely, metrics that measure the difference in the image between the observed image and the nearest view of the object (e.g., the Euclidean distance between corresponding points). In this paper we introduce a different type of metrics: transformation metrics. These metrics penalize for the deformations applied to the object to produce the observed image. We present a transformation metric that optimally penalizes for `affine deformations' under weak-perspective. A closed-form solution, together with the nearest view according to this metric, are derived. The metric is shown to be equivalent to the Euclidean image metric, in the sense that they bound each other from both above and below. For the Euclidean image metric we offer a sub-optimal closed-form solution and an iterative scheme to compute the exact solution.
To efficiently use wavelet transforms in parallel mesh architectures, we need to identify efficient embeddings of wavelet transform coefficients into such meshes. We consider two forms of 2D wavelet transform embeddin...
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ISBN:
(纸本)0818638826
To efficiently use wavelet transforms in parallel mesh architectures, we need to identify efficient embeddings of wavelet transform coefficients into such meshes. We consider two forms of 2D wavelet transform embedding into 2D meshes (with and without reconfigurability) and compare time performances for these embeddings over classes of imageprocessing.algorithms - demonstrating the superiority of one of these embeddings.
We propose a multi-layer, `depth planes' approach to image segmentation where pixels that may have arisen from a single smooth surface in the scene are represented in a common layer. Two types of output are produc...
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ISBN:
(纸本)081863880X
We propose a multi-layer, `depth planes' approach to image segmentation where pixels that may have arisen from a single smooth surface in the scene are represented in a common layer. Two types of output are produced at each pixel: a layer number and a vector of depth values, one value for each layer. The layer assignment performs image partitioning based on surface properties. The depth value assignment for each layer either represents the input data with the noise removed or interpolates between data values to fill-in non-visible parts of the scene. The disjoint surfaces due to occlusion or transparency are also grouped together if they form a smooth surface.
This paper is devoted to spatio-temporal segmentation in echocardiographic images sequences. We combine spatial properties and temporal properties in order to compute segmentation and tracking in a single process. The...
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ISBN:
(纸本)081863880X
This paper is devoted to spatio-temporal segmentation in echocardiographic images sequences. We combine spatial properties and temporal properties in order to compute segmentation and tracking in a single process. The MRF framework is used for modeling the energy function because it allows one to make use simultaneously of local properties, global information, and temporal regularity. Starting from a reference image, where a manual segmentation is made, we develop a method to estimate the model parameters. Such estimation is a crucial point in MRF models. Thus, given an initial segmentation of the sequence, this approach can segment and track a cardiac cavity during the cardiac cycle. We demonstrate its performance on a real echocardiographic sequence.
We address the problem of fast rigid matching of 3-D curves with sub-voxel precision. With respect to earlier work, the method has been adapted for coping with large sets of curves that lie on a surface whose characte...
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ISBN:
(纸本)081863880X
We address the problem of fast rigid matching of 3-D curves with sub-voxel precision. With respect to earlier work, the method has been adapted for coping with large sets of curves that lie on a surface whose characteristics can be locally measured;1. We incorporate 6 different invariants associated with the surface (second fundamental theorem of differential geometry), but measured only along the curve. 2. We introduce an original table, in which we hash values for the 6 transformation parameters (3 parameters for the rotation and 3 for the translation). We present matching results of 3-D curves that permit to register real 3-D medical images.
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