The detection and avoidance of simulated potholes in an autonomous vehicle's path is discussed. A non-contact vision approach in an unstructured environment was utilized for detection. The environment signals were...
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The detection and avoidance of simulated potholes in an autonomous vehicle's path is discussed. A non-contact vision approach in an unstructured environment was utilized for detection. The environment signals were captured by the vehicle's vision system. The brightness threshold to determine pothole's field of view was estimated by a histogram.
This paper presents a study of the impact of MMX technology and PIII Streaming SIMD (Single Instruction stream, Multiple Data stream) Extensions in image processing and machine vision application, which, because of th...
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ISBN:
(纸本)0819438626
This paper presents a study of the impact of MMX technology and PIII Streaming SIMD (Single Instruction stream, Multiple Data stream) Extensions in image processing and machine vision application, which, because of their hard real time constrains, is an undoubtedly challenging task. A comparison with a traditional scalar code and with another parallel SIMD architecture (IMAP-vision board) is discussed with emphasize of the particular programming strategies for speed optimization. More precisely we discuss the low level and intermediate level image processing algorithms, which are best suited for parallel SIMD implementation. High-level image processing algorithms are more suitable for parallel implementation on MIMD architectures. While the IMAP-vision system performs better because of the large number of processing elements, the MMX processor and PIII (with Streaming SIMD Extensions) remains a good candidate for low-level image processing.
An intelligent robot can be utilized to perform tasks that are either hazardous or unpleasant for humans. Such tasks include working in disaster areas or conditions that are, for example, too hot. An intelligent robot...
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An intelligent robot can be utilized to perform tasks that are either hazardous or unpleasant for humans. Such tasks include working in disaster areas or conditions that are, for example, too hot. An intelligent robot can work on its own to some extent, but in some cases the aid of humans will be needed. This requires means for controlling the robot from somewhere else, i.e. teleoperation. Mobile augmented reality can be utilized as a user interface to the environment, as it enhances the user's perception of the situation compared to other interfacing methods and allows the user to perform other tasks while controlling the intelligent robot. Augmented reality is a method that combines virtual objects into the user's perception of the real world. As computer technology evolves, it is possible to build very small devices that have sufficient capabilities for augmented reality applications. We have evaluated the existing wearable computers and mobile augmented reality systems to build a prototype of a future mobile terminal - the CyPhone. A wearable computer with sufficient system resources for applications, wireless communication media with sufficient throughput and enough interfaces for peripherals has been built at the University of Oulu. It is self-sustained in energy, with enough operating time for the applications to be useful, and uses accurate positioning systems.
Since 0. Lummer [6] and the industrial development and production of artificial illuminants it became more and more evident that between sunlight and human vision a specific — until today unexplained — "resonan...
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ISBN:
(纸本)0819438626
Since 0. Lummer [6] and the industrial development and production of artificial illuminants it became more and more evident that between sunlight and human vision a specific — until today unexplained — "resonance" condition apparently exists. Therefore the recommendation holds to approximate as much as possible the spectral energy distribution of artificial illuminants to the one of sunlight. Especially in human color vision spectral shifts of illuminants always lead to hue shifts (cornbined Brightness-, Hue-, Saturation-Shifts) in the perception of colors. These hue shifts in human vision adaptively become compensated with more or less time delay, leading to a relatively good "color constancy" under variable illurninants. An — always far from perfect — explanation model, the von Kries-model, attributes this adaptive compensation of hue shifts to the photopigments in the cones of the human retina. Other — less perfect — models attributing this adaptation to cortical functions also exist [1, 2]. In parallel the need becomes evident to realize future color sensors "capable to measure colors normalized to the spectral sensitivity curves of human vision" [7]. It might be registered with satisfaction that a growing objectivity comes into this psychophysical field of color constancy in human vision by the publication of more and more precise data on relevant parameters in the physical conditions of the experiments.
With the low cost of solid-state camera systems, it is now possible to include many cameras on a mobile robot or other machine. However, video processing is still relatively expensive. Therefore it is often desirable ...
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ISBN:
(纸本)0819438626
With the low cost of solid-state camera systems, it is now possible to include many cameras on a mobile robot or other machine. However, video processing is still relatively expensive. Therefore it is often desirable to share several cameras with a single processor. The purpose of this paper is to describe the design of a video switching system that permits eight cameras to be multiplexed with a single chip. Multiples of eight could also easily be accomplished. The heart of the system is a Maxim video switch. The user simply selects using a three-bit control signal, which camera signal is selected. The output of the video switch is then the desired camera image. One application of this video switch is a four camera input system to a mobile robot being constructed at the University of Cincinnati. Other applications include surveillance and other mobile systems. The decision as to which camera to observe can be made automatically from a computer providing a great versatility. For example, supplemental motion detectors could be used to activate the camera selection for a surveillance system. Higher-level logic has been used on our mobile robot application. Still higher-level logic could be used to fuse the video information in various ways before processing. The significance of this device is that it provides a wealth of video information to be used at the discretion of either a human viewer or automatic system.
intelligent pattern recognition techniques have become important in the fields of computer and robot vision. Our interest focuses on detection of dynamical variables which allows robotic visual units to define object ...
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ISBN:
(纸本)0780358422
intelligent pattern recognition techniques have become important in the fields of computer and robot vision. Our interest focuses on detection of dynamical variables which allows robotic visual units to define object evolution from 2D images. We describe a computational algorithm which predicts the real scene images using spatial Fourier frequency transforms multiplied by transforms of dynamic model integro-differential equations. The theoretical results have been simulated by computer numerical image processing and compared to expected real scenes.
Presents an algorithm for active exploration of the environment by a mobile robot when performing global localization. During the localization process interesting regions for future exploration are selected based on a...
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Presents an algorithm for active exploration of the environment by a mobile robot when performing global localization. During the localization process interesting regions for future exploration are selected based on already detected features and on the hypotheses generated by the localization algorithm. The localization process is improved by presenting it a richer set of features. The proposed algorithm provides highly robust global localization in real world environments with very low computational effort spent in finding exploration goal points. Experimental results are given, demonstrating the effectiveness of the algorithm in a number of different situations.
This paper introduces a fast and efficient indexing approach for both 2D & 3D model-based object recognition in the presence of rotation, translation, and scale Variations of objects. The indexing entries are comp...
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ISBN:
(纸本)0819434302
This paper introduces a fast and efficient indexing approach for both 2D & 3D model-based object recognition in the presence of rotation, translation, and scale Variations of objects. The indexing entries are computed after preprocessing the data by Haar wavelet decomposition. The scheme is based on a unified image feature detection approach based on Zernike moments. A set of low level features, e.g. high precision edges, gray level corners, are estimated by a set of orthogonal Zernike moments, calculated locally around every image point. A high dimensional, highly descriptive indexing entries are then calculated based on the correlation of these local features and employed for fast access to the model database to generate hypotheses. A Bst of the most candidate models is then presented by evaluating the hypotheses. Experimental results are included to demonstrate the effectiveness of the proposed indexing approach.
We apply a model of texture segmentation using multiple spatially and spectrally localized filters, known as Gabor filters, to the analysis of texture and defect regions found on wooden boards. Specifically we present...
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ISBN:
(纸本)0819434302
We apply a model of texture segmentation using multiple spatially and spectrally localized filters, known as Gabor filters, to the analysis of texture and defect regions found on wooden boards. Specifically we present a method to find an optimal set of parameters for a given two-dimensional object detection method. The method uses banks of Gabor filters to limit the range of spatial frequencies, where mutually distinct textures differ significantly in their dominant characterizing frequencies. By encoding images into multiple narrow spatial frequency and orientation channels a local classification of texture regions can be achieved. Unlike other methods applying Gabor filters, we do not use a full Gabor transform, but use feature selection techniques to maximize discrimination. The selection method uses a genetic algorithm to optimize various parameters of the system including Gabor weights, and the parameters of morphological pre-processing. We demonstrate the applicability of the method to the task of classifying wooden textures, and report experimental results using the proposed method.
In this paper a sequence of algorithms for image feature point detection and tracking as well as Euclidian reconstruction of rigid three-dimensional objects from point correspondences is presented. For fully automatic...
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ISBN:
(纸本)0819434302
In this paper a sequence of algorithms for image feature point detection and tracking as well as Euclidian reconstruction of rigid three-dimensional objects from point correspondences is presented. For fully automatic point feature detection, grayvalue images are processed. High-curvature points on contours, i.e. contour elements with locally maximal curvature, are tracked using a normalized correlation algorithm. High-curvature points that could be tracked in a sequence of more than three images are used as point features that are eligible for reconstruction. Since the general way to obtain the epipolar, projective, and Euclidian geometries from point feature correspondences is already solved, here the emphasis is on the performance of the algorithms in the presense of noise. Kanatani's epipolar geometry estimation method is improved and this is experimentally validated. Regarding Bougnoux's Euclidian geometry estimation method, the initial linear solution is now obtained with less uncertainty and the non-linear minimization does no longer converge to a hidden solution. Experimental results are given to assess the system performance.
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