One of the central problems of computervision is segmentation of images into salient features such as edges and surfaces. Different kinds of similarity criteria can be used to group related pixels together. One such ...
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ISBN:
(纸本)0819419524
One of the central problems of computervision is segmentation of images into salient features such as edges and surfaces. Different kinds of similarity criteria can be used to group related pixels together. One such criterion is the curvature of surfaces in an image of a multiobject scene that contains several objects with different shapes. In practice, however, curvature is difficult to calculate because small amount of noise can cause large amounts of errors in calculations of first and second derivatives. In this paper, we use a discrete approximation of Gaussian curvature that is efficient to compute. The approximation is used to segment the image into individual surfaces. Both synthetic and real images have been tested. Results appear quite encouraging.
The aspects of automation technology in industrial one-of-a-kind manufacturing are discussed. An approach to improve the quality and cost relation is developed and an overview of an 3D- vision supported automation sys...
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ISBN:
(纸本)0819419524
The aspects of automation technology in industrial one-of-a-kind manufacturing are discussed. An approach to improve the quality and cost relation is developed and an overview of an 3D- vision supported automation system is given. This system is based on an active vision sensor for 3D-geometry feedback. Its measurement principle, the coded light approach, is explained. The experimental environment for the technical validation of the automation approach is demonstrated, where robot based processes (assembly, arc welding and flame cutting) are graphically simulated and off-line programmed. A typical process sequence for automated one- of-a-kind manufacturing is described. The results of this research development are applied to a project on the automated disassembling of car parts for recycling using industrial robots.
This conference proceedings contain 70 papers. Topics covered include:Pattern recognition in intelligent robotics;Active vision and control;Color image processing;Systems and applications;Robotic navigation, path plan...
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ISBN:
(纸本)0819419524
This conference proceedings contain 70 papers. Topics covered include:Pattern recognition in intelligent robotics;Active vision and control;Color image processing;Systems and applications;Robotic navigation, path planning, and use of motion and image sequences;3D modeling and data processing for robotics and machine vision;Three dimensional pattern recognition for intelligentrobots;Neural nets for pattern recognition and machine vision;Feature extraction;and;Detection and segmentation in machine vision.
We have investigated the problem of removing objects from a heap without having recourse to object models. This capability is useful for `intelligent singulation', i.e., the decomposition of a heap into isolated o...
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ISBN:
(纸本)0819419524
We have investigated the problem of removing objects from a heap without having recourse to object models. This capability is useful for `intelligent singulation', i.e., the decomposition of a heap into isolated objects. As we are exclusively relying on geometric information, the use of range data is a natural choice. To ensure that we see opposite patches of the object surfaces, we use up to three range views from different directions. These views are triangulated using the data points as vertices. After merging the views, the resulting surface description is segmented, i.e., partitioned into large sets of contiguous triangles which correspond to objects or object components in the scene. The system then tries to detect grasping opportunities. Two heuristics guide the selection of a `focus of action' which consists of a suitable component. For this component, good grasping point pairs are found by using an intelligent search technique. If no pairs are found due to impending collisions or bad grasping quality another component is checked. Finally the robot performs the grasping. Force sensing allows the correction of inaccuracies of the vision system and the handling of collisions.
computervision experiments are not very often linked to practical applications but rather deal with typical laboratory experiments under controlled conditions. For instance, most object recognition experiments are ba...
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ISBN:
(纸本)0819419524
computervision experiments are not very often linked to practical applications but rather deal with typical laboratory experiments under controlled conditions. For instance, most object recognition experiments are based on specific models used under limitative constraints. Our work proposes a general framework for rapidly locating significant 3D objects in 2D static images of medium to high complexity, as a prerequisite step to recognition and interpretation when no a priori knowledge of the contents of the scene is assumed. In this paper, a definition of generic objects is proposed, covering the structures that are implied in the image. Under this framework, it must be possible to locate generic objects and assign a significance figure to each one from any image fed to the system. The most significant structure in a given image becomes the focus of interest of the system determining subsequent tasks (like subsequent robot moves, image acquisitions and processing). A survey of existing strategies for locating 3D objects in 2D images is first presented and our approach is defined relative to these strategies. Perceptual grouping paradigms leading to the structural organization of the components of an image are at the core of our approach.
The paper presents a system for the recognition and pose estimation of 3D objects with an emphasis on the segmentation and verification modules. The system is tailored to the analysis of 3D contour images, which are o...
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ISBN:
(纸本)0819419524
The paper presents a system for the recognition and pose estimation of 3D objects with an emphasis on the segmentation and verification modules. The system is tailored to the analysis of 3D contour images, which are obtained from image sequences of a CCD camera by means of Kalman filtering. In order to reduce the search complexity and the noise sensitivity of the recognition process, the method is built on robust contour-based 2D algorithms for the retrieval of model candidates from the database and the generation of pose hypotheses. These techniques apply because of the previous segmentation of the 3D contour image into plane curve segments that make up boundary lines of plane surface patches. Hypotheses for the object's pose are obtained by pairwise matching of model and image boundaries. The subsequent verification computes the best globally consistent assignment of model and image contours by searching for groups of similar pose hypothesis. Both the segmentation and the verification algorithm are formulated in terms of clustering approaches and realized by use of a common technique for the evaluation of transformation space. With regard to industrial applications most importance has been attached to the modular design of a robust software solution and the experimental performance evaluation. Experimental results obtained from real-world images are presented.
Morphological pyramid has been proven to be a useful tool in image compression due to low computational complexity, simple implementation and good compression performance based on minimization of entropy. Several morp...
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ISBN:
(纸本)0819419524
Morphological pyramid has been proven to be a useful tool in image compression due to low computational complexity, simple implementation and good compression performance based on minimization of entropy. Several morphology based pyramid decomposition techniques already exist. These techniques use morphological filters prior to the down sampling of images. The coding schemes developed commonly omit the first error image of the error pyramid to achieve high compression ratios. However, fine image details may be lost in this process. In order to get high quality lossy image, an estimator involving connectivity preserving filters for the first error image has been used. By using this estimator, the bits per pixel required to code the first error image can be reduced by 30 to 40 percent to obtain `near lossless' compression. In this paper, we apply variable Vector Quantization (VQ) to pyramid coding. We compare the performance of the above estimator to that of VQ scheme. For multi- level pyramid, we discuss accumulative errors and use a modified pyramid generation structure to reduce the accumulative errors. We perform our comparison on two standard images and use Peak Signal to Noise Ratio to judge the compression efficiency and visual quality.
In using machine vision for assessing an object's surface quality, many images are required to be processed in order to separate the good areas from the defective ones. Examples can be found in the leather hide gr...
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ISBN:
(纸本)0819419524
In using machine vision for assessing an object's surface quality, many images are required to be processed in order to separate the good areas from the defective ones. Examples can be found in the leather hide grading process; in the inspection of garments/canvas on the production line; in the nesting of irregular shapes into a given surface... . The most common method of subtracting the total area from the sum of defective areas does not give an acceptable indication of how much of the `good' area can be used, particularly if the findings are to be used for the nesting of irregular shapes. This paper presents an image scanning technique which enables the estimation of useable areas within an inspected surface in terms of the user's definition, not the supplier's claims. That is, how much useable area the user can use, not the total good area as the supplier estimated. An important application of the developed technique is in the leather industry where the tanner (the supplier) and the footwear manufacturer (the user) are constantly locked in argument due to disputed quality standards of finished leather hide, which disrupts production schedules and wasted costs in re-grading, re- sorting... . The developed basic algorithm for area scanning of a digital image will be presented. The implementation of an improved scanning algorithm will be discussed in detail. The improved features include Boolean OR operations and many other innovative functions which aim at optimizing the scanning process in terms of computing time and the accurate estimation of useable areas.
Nesting of shoe parts onto a leather hide is a very complex puzzle. This is because firstly, both the shoe parts and the leather hide are of irregular shapes and secondly, leather quality is not uniform throughout the...
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ISBN:
(纸本)0819419524
Nesting of shoe parts onto a leather hide is a very complex puzzle. This is because firstly, both the shoe parts and the leather hide are of irregular shapes and secondly, leather quality is not uniform throughout the hide, certain zones are only suitable for certain types of shoe parts. Moreover, leather hide bears stretch directions which some shoe parts are not permitted to be nested in at certain angles to the hide's stretch directions. Thirdly, the pose of defects in some shoe parts can be acceptable or unacceptable depending on the manufacturer's quality standard. Machine vision researchers have been attempting to capture the hide defect map and use this data file for assisting the computerization nesting of the irregular shapes. There are many challenging tasks in the visual inspection stage which affect the performance of the nesting systems. An essential assignment is the clustering of leather defects. Two vital parameters required in the clustering of defects are the minimum Euclidean distance between defects to be clustered and the re-classification of the newly formed cluster if it contains more than one type of defect or satisfied more serious defect type definition. In order to minimize the wastage in yield, this work recommends that during the inspection stage, only defects of the same type are to be clustered and the process should cease at the point where the newly formed cluster is to become a more serious defect type. The question of minimum Euclidean distance should be considered at both inspection stage as a preliminary clustering operation and at the nesting stage when the shoe size and part shapes are known, as a fine tuned process.
We overview our recent progress in lander-based robotics for Mars planetary science. Utilizing a 1:1 scale laboratory replica of the NASA Mar Surveyor '98 mission, JPL engineers and Mars science colleagues have de...
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ISBN:
(纸本)0819419524
We overview our recent progress in lander-based robotics for Mars planetary science. Utilizing a 1:1 scale laboratory replica of the NASA Mar Surveyor '98 mission, JPL engineers and Mars science colleagues have demonstrated approaches to lander science functions such as robotic sample acquisition and deposition, end-effector based microscopic viewing, hand-carried science instrument data collection, and science instrument emplacement by a robot. Some of the significant technical advances underlying this simulated Mars flight capability include JPL's innovation of a new lightweight, mechanically stiff, gas deployed telescopic two meter robot arm, and cooperative engineering work with Michigan Tech colleagues on automated visual positioning control of robotic sampling. University of Arizona and JPL have further developed complementary advances in lander-based imaging spectroscopy and its robotic enablement. We outline this work, summarizing its key technical features, and illustrating experimental progress with photographs and an accompanying conference videotape.
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