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On the detection of motion and the computation of optical flow 总被引:4,自引:0,他引:4
Duncan J.H. Chou T.-C. 《IEEE transactions on pattern analysis and machine intelligence》1992,14(3):346-352
A method for the detection of motion in image sequences is presented. In this method, the intensity history at each pixel is convolved with the second derivative in time of a temporal Gaussian smoothing function. The zero crossings in a single frame of the resulting function indicate the positions of moving edges. Intensity changes in time due to illumination effects do not produce zero crossings; thus, they are not interpreted as motion by the present method. It is also shown that the spatial and temporal derivatives of this function can be used to compute the component of the optical flow that is normal to the zero-crossing contours. This computation is also insensitive to nonconvective temporal and spatial variations in the image intensity that are caused by illumination effects 相似文献
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A 10-year-old, previously healthy female presented to the emergency department via emergency medical service transport, with her tongue tightly entrapped inside a glass bottle (9 oz, Yoohoo brand of chocolate drink). The tongue was massively edematous and ecchymotic due to impaired venous return from constriction by the neck of the bottle. After repeated attempts at mechanically reducing the tongue out of the bottle, a professional glazier was contacted, who was able to remove the bottle in the operating room with a steel glass cutter. Needle evacuation of a small hematoma was then performed to decrease the pressure ischemia to the tongue, which began to improve quickly. 相似文献
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Cho Younghee; Luce R. Duncan; von Winterfeldt Detlof 《Canadian Metallurgical Quarterly》1994,20(5):931
A rank- and sign-dependent utility theory is based on an operation of joint receipt of 2 independent gambles and 3 assumptions regarding the operation (R. D. Luce, 1992). The authors tested these 3 assumptions (i.e., segregation, duplex decomposition, and the additivity of certainty equivalents over joint receipt) using both judged and choice certainty equivalents (CEs). Median choice CEs provided support for both segregation and duplex decomposition but little support for additivity in gains or in losses, whereas median judged CEs also failed to support segregation. The latter failure appears to result from some Ss misunderstanding the instructions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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SO Trertola SJ Savader CA Prescott FA Osterman 《Canadian Metallurgical Quarterly》1993,189(1):285-286
A simple commercially available compression device allowed intermittent ultrasound scanning of the compression site during compression repair of a femoral artery pseudoaneurysm in six patients. All six of the pseudoaneurysms (five superficial femoral and one common femoral) were compressed without compression of the underlying vessels. The procedure was successful in four of the six patients, without complications. Use of this device may decrease operator fatigue during compression repair of pseudoaneurysm. 相似文献
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