The paper presents a new high-accuracy automatic target tracking algorithm which does not involve image segmentation. The method constructs a function which is based on local gray- level information. The function can ...
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ISBN:
(纸本)0819405914
The paper presents a new high-accuracy automatic target tracking algorithm which does not involve image segmentation. The method constructs a function which is based on local gray- level information. The function can evaluate the deviation vector between the target's center and the tracking window center and then automatically adjust the tracking window iteratively towards the target's center to achieve automatic target tracking. The algorithm can achieve high tracking accuracy. It is not sensitive to noise and is not restrained by the movement pattern of the target. As the method does not use segment processing, it provides better real- time quality, a short processing period, and is very easily implemented. The implementation by the microcomputer imageprocessing system demonstrates that the method is especially practical for infrared images and works well for infrared images in complex environment.
Three-dimensional (3D) medical imaging deals with the visualization, manipulation, and measuring of objects in 3D medical images. So far, research efforts have concentrated primarily on visualization, using well-devel...
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ISBN:
(纸本)081940540X
Three-dimensional (3D) medical imaging deals with the visualization, manipulation, and measuring of objects in 3D medical images. So far, research efforts have concentrated primarily on visualization, using well-developed methods from computer graphics. very little has been achieved in developing techniques for manipulating medical objects, or for extracting quantitative measurements from them beyond volume calculation (by counting voxels), and computing distances and angles between manually located surface points. A major reason for the slow pace in the development of manipulation and quantification methods lies with the limitations of current algorithms for constructing surfaces from 3D solid objects. We show that current surface construction algorithms either (a) do not construct valid surface descriptions of solid objects or (b) produce surface representations that are not particularly suitable for anything other than visualization. We present ALLIGATOR, a new surface construction algorithm that produces valid, topologically connected surface representations of solid objects. We have developed a modeling system based on the surface representations created by ALLIGATOR that is suitable for developing algorithms to visualize, manipulate, and quantify 3D medical objects. Using this modeling system we have developed a method for efficiently computing principle curvatures and directions on surfaces. These measurements form the basis for a new metric system being developed for morphometrics. The modeling system is also being used in the development of systems for quantitative pre-surgical planning and surgical augmentation.
An algorithm working on monocular gray-scale image sequences for object detection combined with a road tracker is presented. This algorithm appropriate for the real-time demands of an autonomous car driving with speed...
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ISBN:
(纸本)0819404551
An algorithm working on monocular gray-scale image sequences for object detection combined with a road tracker is presented. This algorithm appropriate for the real-time demands of an autonomous car driving with speeds over 40 km/h may be used for triggering obstacle avoidance maneuvers such as coming to a safe stop automatically in front of an obstacle or following another car. Moving and static objects have been detected in real-world experiments on various types of roads even under unfavorable weather conditions. . Morgenthaler and
This paper addresses the problem of imaging a dynamic object with an imaging modality that utilizes a single illumination instead of sequential sector scanning used in conjunction with B-scanners. Two data collection ...
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ISBN:
(纸本)0819405388
This paper addresses the problem of imaging a dynamic object with an imaging modality that utilizes a single illumination instead of sequential sector scanning used in conjunction with B-scanners. Two data collection strategies and their associated reconstruction algorithms are presented for dynamic object imaging. One scheme utilizes a single unfocused wave transmitted by an element of an array. In the other method, the elements of an array simultaneously illuminate the object with unfocused multiplexed waves. The data base acquired in either of these methods is sufficient for the recovery of the object's monostatic synthetic aperture data and reconstruction.
In automatic assembly tasks guided by vision it is necessary to determine the position x,y and the orientation of a given element of the target. This work describes the image processor used to evaluate the shift of th...
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ISBN:
(纸本)0819405914
In automatic assembly tasks guided by vision it is necessary to determine the position x,y and the orientation of a given element of the target. This work describes the image processor used to evaluate the shift of the target every 20 ms and thus to obtain a better guidance dynamic response.
High-resolution data from the HRv (High Resolution visible) sensors onboard the SPOT-1 satellite have been utilized for mapping semi-natural and agricultural land cover using automated digital image classification alg...
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High-resolution data from the HRv (High Resolution visible) sensors onboard the SPOT-1 satellite have been utilized for mapping semi-natural and agricultural land cover using automated digital image classification algorithms. Two methods for improving classification performance are discussed. The first technique involves the use of digital terrain information to reduce the effects of topography on spectral information while the second technique involves the classification of land-cover types using training data derived from spectral feature space. Test areas in Snowdonia and the Somerset Levels were used to evaluate the methodology and promising results were achieved. However, the low classification accuracies obtained suggest that spectral classification alone is not a suitable tool to use in the mapping of semi-natural cover types.
After the stage of pointlike target tracking, the tracker comes to the stage of area target tracking. This paper considers the situation in which the FLIR image contains a number of targets. The targets are compact. T...
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ISBN:
(纸本)0819405914
After the stage of pointlike target tracking, the tracker comes to the stage of area target tracking. This paper considers the situation in which the FLIR image contains a number of targets. The targets are compact. The image segmentation is achieved by considering not only the global gray-level distribution but also the spatial distribution of target pixels. After the global gray-level statistics in the whole image, a recursive merging algorithm, a hierarchical clustering on the gray level and spatial position, is applied to segment the image into a multiple gray-level image. To make full use of the whole scene scan, a four direction code method is used to depict the edges of target regions. And to save more execution time, the useful features, including structure feature and geometry feature, are calculated by the four direction code expression at the same time. Thus the target edge description and the useful features calculation are finished in the same whole scene scan of the segmented image. A changing index table which describes targets and their features within the segmented image is set up. The index table is updated at each scene to depict the changing content of the image. During the time in which the image gets into a comparable stable state, a target recognition procedure may be applied to find the interested target, and the threatening value of each target is considered. An adaptive gate is assigned to each interested target.
A mathematical model for a typical CCD camera system used in machine vision applications is presented. This model is useful in research and development of machine vision systems, and in the computer simulation of came...
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A mathematical model for a typical CCD camera system used in machine vision applications is presented. This model is useful in research and development of machine vision systems, and in the computer simulation of camera systems. The model has been developed with the intention of using it to investigate algorithms for recovering depth from image blur. However, the model is general and can be used to address other problems in machine vision. The model is based on a precise definition of input to the camera system. This definition decouples the photometric properties of a scene from the geometric properties of the scene in the input to the camera system. An ordered sequence of about 20 operations are defined which transform the camera system's input to its output, i.e. digital image data. Each operation in the sequence usually defines the effect of one component of the camera system on the input. This model underscores the complexity of the actual imaging process which is routinely underestimated and oversimplified in machine vision research.
The method presented is based on iterating the tracking window center towards the center of the target. The algorithm doesn't require the target inside the tracking window initially. The tracking window can then b...
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ISBN:
(纸本)0819405914
The method presented is based on iterating the tracking window center towards the center of the target. The algorithm doesn't require the target inside the tracking window initially. The tracking window can then be adjusted iteratively towards the center of the target and achieve high tracking accuracy within only one frame of the image. In the process of executing several frames of target image tracking, it can evaluate some movement parameters and some physical parameters of the target. In addition, this algorithm is not restrained by the pattern of the target movement, and has a short processing period, good real-time quality, and insensitiveness to noise. Computer IP system simulations show that the algorithm works well for a variety of targets, and the center tracking error is less than 0.2 pixel per frame under the middle SNR condition.
Autonomous navigation capabilities need to be developed if mobile robots are to be used effectively in complex environments. This paper summarizes the further development and implementation of a system for model based...
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ISBN:
(纸本)0819404551
Autonomous navigation capabilities need to be developed if mobile robots are to be used effectively in complex environments. This paper summarizes the further development and implementation of a system for model based autonomous navigation of mobile robots within complex structures. The developed system architecture addresses the complete navigation problem from high level path planning using facility data to lower level autonomous movement through uncertain local environments. A 3D laser imager is used as the primary sensor. It returns real-time detailed range and reflectance images. The system was developed for the application of navigating a mobile teleoperated robot to a remote work site in a nuclear power plant. An overhead gantry and physical models of nuclear power plant Structures are used as a testbed for 3D navigation algoritbms. Navigation architecture algorithms and test results are presented.
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