In this work, a camera with integrated image processing capabilities is discussed. The camera is based on an imager coupled to an FPGA device (Field Programmable Gate Array) which contains an architecture for real-tim...
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ISBN:
(纸本)081944300X
In this work, a camera with integrated image processing capabilities is discussed. The camera is based on an imager coupled to an FPGA device (Field Programmable Gate Array) which contains an architecture for real-time computervision low-level processing. The architecture can be reprogrammed remotely for application specific purposes. The system is intended for rapid modification and adaptation for inspection and recognition applications, with the flexibility of hardware and software reprogrammability. FPGA reconfiguration allows the same ease of upgrade in hardware as a software upgrade process. The camera is composed of a digital imager coupled to an FPGA device, two memory banks, and a microcontroller. The microcontroller is used for communication tasks and FPGA programming. The system implements a software architecture to handle multiple FPGA architectures in the device, and the possibility to download a software/hardware object from the host computer, into its internal context memory. System advantages are: small size, low power consumption, and a library of hardware/software funcionalities that can be exchanged during run-time. The system has been validated with an edge detection and a motion processing architectures, which will be presented in the paper. Applications targeted are in robotics, mobile robotics, and vision based quality control.
We have proposed a boundary extraction algorithm for cross-sectional critical dimension (CD) measurements of the scanning electron microscope (SEM) images in machine/computervision. Noisy SEM images have the image di...
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ISBN:
(纸本)081944300X
We have proposed a boundary extraction algorithm for cross-sectional critical dimension (CD) measurements of the scanning electron microscope (SEM) images in machine/computervision. Noisy SEM images have the image discontinuity of roof edge with peak. A task is to extract a low contrast boundary or edge with about one pixel width in a noisy cross sectional SEM image. Also CD measurements require that the algorithm locate a boundary or an edge at the correct position. Our policy is to detect the edges with high degree of confidence at first, and then to extract the edges with the high probabilities of edge that are calculated by using gray levels of neighboring pixels. Our proposed algorithm integrates the Gaussian pyramid to suppress noise, morphological operations to detect the edges with high degree of confidence, the relaxation method to recover the gaps in the detected edges, and the hierarchical approach. Application of the proposed algorithm to cross sectional SEM images of DRAMs shows its validity.
For robust and secure behavior in natural environment an autonomous vehicle needs an elaborate vision sensor as main source of information. The vision sensor must be adaptable to the external situation, the mission, t...
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ISBN:
(纸本)081944300X
For robust and secure behavior in natural environment an autonomous vehicle needs an elaborate vision sensor as main source of information. The vision sensor must be adaptable to the external situation, the mission, the capabilities of the vehicle and the knowledge about the external world accumulated up to the present time. In the EMS-vision system, this vision sensor consists of four cameras with different focal lengths mounted on a highly dynamic pan-tilt camera head. Image processing, gaze control and behavior decision interact with each other in a closed loop. The image processing experts specify so-called regions of attention (RoAs) for each object in 3D object coordinates. These RoAs should be visible with a resolution as required by the measurement techniques applied. The behavior decision module specifies the relevance of obstacles like road segments, crossings or landmarks in the situation context. The gaze control unit takes all this information in order to plan, optimize and perform a sequence of smooth pursuits, interrupted by saccades. The sequence with the best information gain is performed. ne information gain depends on the relevance of objects or object parts, the duration of smooth pursuit maneuvers, the quality of perception and the number of saccades. The functioning of the EMS-vision system is demonstrated in a complex and scalable autonomous mission with the UBM test vehicle VAMORS.
2D vision in a 3D System will be an overview of important software and mechanical issues related to designing and implementing a system with 3-dimensional characteristics constrained by a 2-dimensional vision system. ...
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ISBN:
(纸本)081944300X
2D vision in a 3D System will be an overview of important software and mechanical issues related to designing and implementing a system with 3-dimensional characteristics constrained by a 2-dimensional vision system. A general methodology for choosing the right components, including cameras, optics, and lighting will be discussed. Some choices for image processing techniques, related in particular to calibration and pattern-matching approaches, will be overviewed. The discussion will involve approaches to auto-focusing and additional mathematical algorithms that may likely be required. These issues will include world-to-camera transformations and considerations to take when dealing with rotational attributes. The presentation is intended primarily for software engineers and/or other engineers that would be involved in the prototyping, design, and implementation phases of such a project. Typical examples of such systems will be cited and a more in-depth overview of a particular example will be made. Some typical pitfalls, both mechanical and software-related, will also be broached.
vision is a part of a larger information system that converts visual information into knowledge structures. These structures drive vision process, resolving ambiguity and uncertainty via feedback, and provide image un...
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ISBN:
(纸本)081944300X
vision is a part of a larger information system that converts visual information into knowledge structures. These structures drive vision process, resolving ambiguity and uncertainty via feedback, and provide image understanding, that is an interpretation of visual information in terms of such knowledge models. A computervision system based on such principles requires unifying representation of perceptual and conceptual information. computer simulation models are built on the basis of graphs/networks. The ability of human brain to emulate similar graph/networks models is found. That means a very important shift of paradigm in our knowledge about brain from neural networks to the "cortical software". Starting from the primary visual areas, brain analyzes an image as a graph-type spatial structure. Primary areas provide active fusion of image features on a spatial grid-like structure, where nodes are cortical columns. The spatial combination of different neighbor features cannot be described as a statistical/integral characteristic of the analyzed region, but uniquely characterizes such region itself. Spatial logic and topology naturally present in such structures. Mid-level vision processes like clustering, perceptual grouping, multilevel hierarchical compression, separation of figure from ground, etc. are special kinds of graph/network transformations. They convert low-level image structure into the set of more abstract ones, which represent objects and visual scene, making them easy for analysis by higher-level knowledge structures. Higher-level vision phenomena like shape from shading, occlusion, etc. are results of such analysis. Such approach gives opportunity not only to explain frequently "unexplainable" results of the cognitive science, but also to create intelligentcomputervision systems that simulate perceptional processes in both "what" and "where" visual pathways. Such systems can open new horizons for robotic and computervision industries.
In this study we use genetic algorithms to generate test surfaces for a proposed structured light 3-D vision system in order to estimate the worst case behavior of error tolerances. The object software evaluates surfa...
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ISBN:
(纸本)081944300X
In this study we use genetic algorithms to generate test surfaces for a proposed structured light 3-D vision system in order to estimate the worst case behavior of error tolerances. The object software evaluates surface profiles for measuring volumes of small objects attached on surfaces that are highly constrained while somewhat arbitrarily shaped. The test system tries to find, by using genetic algorithm search, the shape that results the highest relative error of volume. The parameters of the object system to be optimized include laser angle, image size, object step size, and the number of scan directions. The preliminary results got seem to indicate that a genetic algorithm based approach is a beneficial aid in optical system design.
Typical surface inspection tasks using RGB vision require the analysis of tens of megabytes of image data per second, with low false alarm and error escape rates. Although automatic inspection systems have become more...
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ISBN:
(纸本)081944300X
Typical surface inspection tasks using RGB vision require the analysis of tens of megabytes of image data per second, with low false alarm and error escape rates. Although automatic inspection systems have become more common on production lines, for example in sawmills, there are substantial needs to improve their performance and accuracy. Detection is one very important part of image flow before defect recognition. Detection is used in order to find suspicious regions of the image, containing possibly defective areas, since defect detection has to cope with very high data rates. It has to be based on relative simple methods. In this paper we describe the effect of different thresholding methods in RGB defect detection. Threshold values were calculated for R, G and B channels, difference channels \R-G\, \R-B\ and \G-B\ and for mean values from R, G and B channels. The analysis was performed for pine-wood. Error escape rate and false alarm rates were used as evaluation criteria. In this paper, R and G channel thresholding methods were the best ones.
The purpose of this paper is to present a real-time vision system for position determination and vision guidance to navigate an autonomous mobile robot in a known environment. We use a digital camera, which provide te...
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ISBN:
(纸本)081944300X
The purpose of this paper is to present a real-time vision system for position determination and vision guidance to navigate an autonomous mobile robot in a known environment. We use a digital camera, which provide ten times the video capture bandwidth then a USB, using FireWire interface. In order to achieve real-time image processing we use MMX technology to accelerate vision tasks. Camera calibration is a necessary step in 3D computervision in order to extract metric information from 2D images. Calibration is used to determine the camera parameters by minimizing the mean square error between model and calibration points. The camera calibration we use here is based on several views of a planar calibration pattern, which is an easy to use and accurate algorithm. For position pose of the robot we use the corner points and lines, features extracted from the image, and matched with the model of the environment. The algorithm is as follows: first we compute an initial pose using the Ganatipathy's four point algorithm and we use this initial estimation as the starting point for the iterative algorithm proposed by Araujo in order to refine our pose.
The purpose of this paper is to describe the use of Global Positioning Systems (GPS) as geographic information and navigational system for a ground based mobile robot. Several low cost wireless systems are now availab...
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ISBN:
(纸本)081944300X
The purpose of this paper is to describe the use of Global Positioning Systems (GPS) as geographic information and navigational system for a ground based mobile robot. Several low cost wireless systems are now available for a variety of innovative automobile applications including location, messaging and tracking and security. Experiments were conducted with a test bed mobile robot, Bearcat II, for point-to-point motion using a Motorola GPS in June 2001. The Motorola M12 Oncore GPS system is connected to the Bearcat U main control computer through a RS232 interface. A mapping program is used to define a desired route. Then GPS information may be displayed for verification. However, the GPS information is also used to update the control points of the mobile robot using a reinforcement learning method. Local position updates are also used when found in the environment. The significance of the method is in extending the use of GPS to local vehicle control that requires more resolution that is available from the raw data using the adaptive control method.
We are developing a nursing system using robots and cameras. The cameras are mounted on a remote controlled monorail robot which moves inside a room and watches the elderly. It is necessary to pay attentions to the el...
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ISBN:
(纸本)081944300X
We are developing a nursing system using robots and cameras. The cameras are mounted on a remote controlled monorail robot which moves inside a room and watches the elderly. It is necessary to pay attentions to the elderly at home or nursing homes all time. This requires staffs to pay attentions to them at every time. The purpose of our system is to help those staffs. This study intends to improve such situation. A host computer controls a monorail robot to go in front of the elderly using the images taken by cameras on the ceiling. A CCD camera is mounted on the monorail robot to take pictures of their facial expression or movements. The robot sends the images to a host computer that checks them whether something unusual happens or not. We propose a simple calibration method for positioning the monorail robots to track the move of the elderly for keeping their face at center of camera view. We built a small experiment system, and evaluated our camera calibration method and image processing algorithm.
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