We describe a high-accuracy inspection system designed to automatically detect cracks in "as-cast" steel slabs. Real-time slab inspection requires instrumentation capable of withstanding high temperatures ab...
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ISBN:
(纸本)9781509024919
We describe a high-accuracy inspection system designed to automatically detect cracks in "as-cast" steel slabs. Real-time slab inspection requires instrumentation capable of withstanding high temperatures above the steel surface as well as coping with the dirty and dusty environment present in a steel mill. Crack detection is also challenging due to the presence of oxidation scale on the slab surface. A bespoke laser triangulation system has been developed, providing images at 250 fps with a calibrated surface resolution of 97 mu m from a 1m standoff distance. Cracks are detected using a combination of morphological detection and SVM classifier. Results are reported from laboratory testing and from extended trials at a production steel mill.
When a network of vision-based sensors is emplaced in an environment for applications such as surveillance or monitoring the spatial relationships between the sensing units must be inferred or computed for self-calibr...
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When a network of vision-based sensors is emplaced in an environment for applications such as surveillance or monitoring the spatial relationships between the sensing units must be inferred or computed for self-calibration purposes. In this paper we describe a technique to solve one aspect of this self-calibration problem: automatically determining the topology and connectivity information of a network of cameras based on a statistical analysis of observed motion in the environment. While the technique can use labels from reliable cameras systems, the algorithm is powerful enough to function using ambiguous tracking data. The method requires no prior knowledge of the relative locations of the cameras and operates under very weak environmental assumptions. Our approach stochastically samples plausible agent trajectories based on a delay model that allows for transitions to and from sources and sinks in the environment. The technique demonstrates considerable robustness both to sensor error and non-trivial patterns of agent motion. The output of the method is a Markov model describing the behavior of agents in the system and the underlying traffic patterns. The concept is demonstrated with simulation data for systems containing up to 10 agents and verified with experiments conducted on a six camera sensor network. (C) 2006 Elsevier B.V. All rights reserved.
In this paper we discuss determining canine pose in the context of common poses observed in Urban Search and Rescue dogs through the use a sensor network made up of accelerometers. We discuss the use of the Canine Pos...
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ISBN:
(纸本)9781424442119
In this paper we discuss determining canine pose in the context of common poses observed in Urban Search and Rescue dogs through the use a sensor network made up of accelerometers. We discuss the use of the Canine Pose Estimation System in a disaster environment, and propose techniques for determining canine pose. In addition we discuss the challenges with this approach in such environments. This paper presents the experimental results obtained from the Heavy Urban Search and Rescue disaster simulation, where experiments were conducted using multiple canines, which show that angles can be derived from acceleration readings. Our experiments show that similar angles were measured for each of the poses, even when measured on multiple USAR canines of varying size. We also developed an algorithm to determine poses and display the current canine pose to the screen of a laptop. The algorithm was successful in determining some poses and had difficulty, with others. These results are presented and discussed in this paper.
The shape completion problem refers to the interruption, e.g. by occlusion, of the geometric continuation of boundaries of objects. It is important to use a single visually pleasing curve segment to smoothly fill a ga...
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ISBN:
(纸本)9780769531533
The shape completion problem refers to the interruption, e.g. by occlusion, of the geometric continuation of boundaries of objects. It is important to use a single visually pleasing curve segment to smoothly fill a gap, even though the gap may not be filled in a curvature continuous manner Recently an algorithm for doing so using an Euler spiral segment was presented, the algorithm depends on initially fitting a biarc. An improved algorithm, which does not depend on first fitting a biarc, is now presented.
The proceedings contain 77 papers. The topics discussed include: learning to classify by ongoing feature selection;local feature matching for face recognition;automated detection of unusual events on stairs;interpreti...
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ISBN:
(纸本)0769525423
The proceedings contain 77 papers. The topics discussed include: learning to classify by ongoing feature selection;local feature matching for face recognition;automated detection of unusual events on stairs;interpreting camera operations in the context of content-based video indexing and retrieval;automatic classification of outdoor images by region matching;using 3D spline differentiation to compute quantitative optical flow;confidence based updation of motion conspicuity in dynamic scenes;photometric stereo with nearby planar distributed illuminants;photo hull regularized stereo;urban position estimation from one dimensional visual cues;determining shot accuracy of a robotic pool system;image thresholding using ant colony optimization;robust image segmentation using local median;multiple-sensor indoor surveillance system;3D face reconstruction from stereo video;simple software for microarray image analysis;and image classification and retrieval using correlation.
We present SHREC, an efficient algorithm for registration of 3D SPHARM (spherical harmonic) surfaces. SHREC follows the iterative closest point (ICP) registration strategy, and alternately improves the surface corresp...
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ISBN:
(纸本)9780769527864
We present SHREC, an efficient algorithm for registration of 3D SPHARM (spherical harmonic) surfaces. SHREC follows the iterative closest point (ICP) registration strategy, and alternately improves the surface correspondence and adjusts the object pose. It establishes the surface correspondence by aligning the underlying SPHARM parameterization. It employs a rotational property of the harmonic expansion to accelerate its step for parameterization rotation. It uses a hierarchical icosahedron approach to sample the rotation space and searches for the best parameterization that matches the template. Our experimental results show that SHREC can not only create more accurate registration than previous methods but also do it efficiently. SHREC is a simple, efficient and general registration method, and has a great potential to be used in many shape modeling and analysis applications.
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