The face recognition, one of the most important ability of intelligentvision, are discussed in this paper. A new idea of model-based processing are presented. The algorithms of face modeling, global matching and fine...
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ISBN:
(纸本)0819423068
The face recognition, one of the most important ability of intelligentvision, are discussed in this paper. A new idea of model-based processing are presented. The algorithms of face modeling, global matching and fine matching, and feature points extraction etc. are given Finally, a rapid and robust scheme for human face recognition are resulted.
A special case of civilian activevision has been investigated here, namely, a vision system by car anti-fog headlamps. A method to estimate the light-engineering criteria for headlamp performances and simulate the op...
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ISBN:
(纸本)0819423068;9780819423061
A special case of civilian activevision has been investigated here, namely, a vision system by car anti-fog headlamps. A method to estimate the light-engineering criteria for headlamp performances and simulate the operation of the system through a turbid medium, such as fog, is developed on the base of the analytical procedures of the radiative transfer theory. This method features in include the spaced light source and receiver of a driver's activevision system, the complicated azimuth-nonsymmetrical emissive pattern of the headlamps, and the fine angular dependence of the fog phase function near the backscattering direction. The final formulas are derived in an analytical form providing additional convenience and simplicity for the computations. The image contrast of a road object with arbitrary orientation, dimensions, and shape and its limiting visibility range are studied as a function of meteorological visibility range in fog as well as of various emissive pattern, mounting, and adjustment parameters of the headlamps. Optimization both light-engineering and geometrical characteristics of the headlamps is shown to be possible to enable the opportunity to enhance the visibility range and, hence, traffic safety.
Knowledge of the bidirectional optical scatter function of surfaces comprising a 2D scene is used to predict and optimize characteristics of a digitally captured image of the scene. Mathematical expressions that descr...
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ISBN:
(纸本)0819423068;9780819423061
Knowledge of the bidirectional optical scatter function of surfaces comprising a 2D scene is used to predict and optimize characteristics of a digitally captured image of the scene. Mathematical expressions that describe certain image properties including contrast, brightness, glare, etc., are developed from the scatter functions. It is these mathematical expressions that are maximized or minimized with respect to a set of coordinates used to describe the orientation of a collimated light source and imaging system relative to the scene. In this way, it is shown how illumination can be analytically prescribed to attenuated or accentuated certain properties of digital images without the trial-and-error procedure currently in practice.
Based on the concept of object- and behavior-oriented stereo vision, a method is introduced which enables a robot manipulator to handle two distinct types of objects. It uses an uncalibrated stereo vision system and a...
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ISBN:
(纸本)0819423068;9780819423061
Based on the concept of object- and behavior-oriented stereo vision, a method is introduced which enables a robot manipulator to handle two distinct types of objects. It uses an uncalibrated stereo vision system and allows a direct transition from image coordinates to motion control commands of a robot. An object can be placed anywhere in the robot's 3D work space which is in the field of view of both cameras. The objects to be manipulated can either be of flat cylindrical or elongate shape. Results gained from real-world experiments are discussed.
Current developments in the field of automated assembly systems show an increasing interest in systems that are flexible in both CAD based product design and CAD based assembly. For the application addressed in this p...
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ISBN:
(纸本)0819423068;9780819423061
Current developments in the field of automated assembly systems show an increasing interest in systems that are flexible in both CAD based product design and CAD based assembly. For the application addressed in this paper, coupling the vision system and a CAD database is of prime importance in order to achieve the required automatic reconfiguration of the assembly cell when new parts are defined. This paper presents a 3D CAD-based vision system for obtaining 3D data about the scene. After the images are acquired, edge detection is preformed and the detected edges are stored as chaincodes. Following that, a stereo vision algorithm is applied for finding the recognition features. The output are lists of features that are combined into a 3D wireframe representing the scene. The recognition algorithm takes the observed wireframe outputs from the stereo vision system, and compares them with a set of model wireframes derived from previous models, in order to select the 'best match', where the previous models used for recognition are derived from a product data model (PDM). The PDM is an interface between the CAD database and the recognition system, which allows the automatic generation of new models when new parts are introduced into the system. The vision system described in this paper is part of an intelligent robotic assembly cell, where the aim is to build a flexible intelligent robotic assembly cell, such that robots would be able to automatically assemble a random variety of small-batch products.
We discuss the uniqueness of 3D shape recovery of a polyhedron from a single shading image, and propose an approach to uniquely determine the concave shape solution by using interreflections as a constraint. We show t...
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ISBN:
(纸本)0819423068;9780819423061
We discuss the uniqueness of 3D shape recovery of a polyhedron from a single shading image, and propose an approach to uniquely determine the concave shape solution by using interreflections as a constraint. We show that if interreflection distribution is not considered, multiple convex shape solutions usually exist for a pyramid with three or more visible facets. However, if interreflection distribution is used as a constraint to limits the shape of polyhedron, polyhedral shape can be uniquely determined. Interreflections, which were considered to be deleterious in conventional approaches, are an important constraint for shape-from-shading.
A camera system to be used in a tactile vision aid for blind persons has been built and tested. The camera is based on individual adaptive photoreceptors modelled after the biological example and realized in standard ...
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ISBN:
(纸本)0819423068;9780819423061
A camera system to be used in a tactile vision aid for blind persons has been built and tested. The camera is based on individual adaptive photoreceptors modelled after the biological example and realized in standard CMOS technology. The system exhibits a large dynamic range of approximately 7 orders of magnitude in incident light intensity and a pronounced capability to detect moving objects. It is planned to connect such a camera to a set of mechanical actuators which will transmit processed information about the image to the skin of a person. This paper describes simulations and measurements carried out with single adaptive pixels as well as results obtained with two complete prototype camera systems.
The term 'activevision' was first used by Bajcsy at a NATO workshop in 1982 to describe an emerging field of robot vision which departed sharply from traditional paradigms of image understanding and machine v...
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ISBN:
(纸本)0819423068;9780819423061
The term 'activevision' was first used by Bajcsy at a NATO workshop in 1982 to describe an emerging field of robot vision which departed sharply from traditional paradigms of image understanding and machine vision. The new approach embeds a moving camera platform as an in-the-loop component of robotic navigation or hand-eye coordination. Visually served steering of the focus of attention supersedes the traditional functions of recognition and gaging. Custom activevision platforms soon proliferated in research laboratories in Europe and North America. In 1990 the National Science Foundation funded the design of a common platform to promote cooperation and reduce cost in activevision research. This paper describes the resulting platform. The design was driven by payload requirements for binocular motorized C-mount lenses on a platform whose performance and articulation emulate those of the human eye-head system. The result was a 4-DOF mechanisms driven by servo controlled DC brush motors. A crossbeam supports two independent worm-gear driven camera vergence mounts at speeds up to 1,000 degrees per second over a range of ± 90 degrees from dead ahead. This crossbeam is supported by a pan-tilt mount whose horizontal axis intersects the vergence axes for translation-free camera rotation about these axes at speeds up to 500 degrees per second.
Robust range estimation is one of the most important tasks in mobile robotics. This paper presents a new optical arrangement for utilizing the previously known 'depth from defocus' principle. The arrangement m...
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ISBN:
(纸本)0819423068;9780819423061
Robust range estimation is one of the most important tasks in mobile robotics. This paper presents a new optical arrangement for utilizing the previously known 'depth from defocus' principle. The arrangement makes it possible to apply standard video lenses and camera modules for making a compact range camera system. Real-time processing is made possible with a single-board DSP card.
activevision is identified by a closed loop linking sensing with acting. Thus, an activevision system's behavior is directly determined by what it senses. To date however, the responses produced by activevision...
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ISBN:
(纸本)0819423068;9780819423061
activevision is identified by a closed loop linking sensing with acting. Thus, an activevision system's behavior is directly determined by what it senses. To date however, the responses produced by activevision systems have tended to be relatively low-level, generally designed to facilitate improved sensing, by enhancing the duration or speed of object tracking, for example, or optimizing the focused application of more intensive image processing. This is probably adequate if the activevision system is designed as a front end to other processes or to specialized application systems, or if it is a demonstration in support of a theoretical vision model. However, this leaves unanswered the problems of i) how to select an appropriate action when many different alternatives are available, and ii) how best to modify the behavioral repertoire of the system. These problems are especially important in two situations: firstly, when an autonomous system faces a novel situation and must respond adaptively without the benefit of a priori knowledge, and secondly, when systems attempt higher levels of perception and response, and links between the absolute properties of the incoming image data and the actual objects of perception become increasingly attenuated. This paper discusses methods for linking learning with activevision so that the behavior of the system is optimized over time for the achievement of goals. We argue the necessity of system goals in learning vision systems, and discuss methods for propagating goals through all levels of loose hierarchies. In the last section we outline an architecture in which high and low level perception operate interactively and in parallel.
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