Accurate Moving Objects Extraction And Tracking In Motion Vision

Moving objects extraction and tracking is a basic and important step in computer vision application field, such as visual analysis, high-level behavior understanding and motion coding, and they are also challenges in research field of computer vision. In this dissertation, accurate moving objects extraction and tracking in motion vision are studied in depth, including motion detection, shadow suppression, contour extraction of moving objects, and objects tracking.The major contributions of this dissertation are summarized as follows:1. In order to determine the threshold for motion detection, two-dimensional spatio-temporal entropy principle is used to determine the threshold adaptively. Aiming at reducing the complexity of traditional two-dimensional entropic thresholding method, a fast iterative solution is deduced, and wavelet transformation is used to decrease the search scope of threshold candidates. On the basis of above research, another new solution for two-dimensional entropy threshold is deduced, in which repeated calculation is avoided by using integral and iterative operation, thus further reducing the computational complexity. This method is applied successfully to motion detection which is based on frame difference or background subtraction.2. Fuzzy theory is introduced to original entropy principle, and fuzzy entropy principle is formed. A fast solution for calculating the two-dimensional fuzzy entropy threshold is deduced, in which the various calculation operation is reduced from O ( N 4) to less than O ( N 3) for N gray-level image. Compared to the two-dimensional entropic thresholding method, this method has better performance on both motion information extraction and noise suppression.3. A shadow suppression method which combines chrominance distortion and texture feature is proposed. The distribution rule of the chrominance and the cross correlation of texture after and before shadow appears are analyzed, different shadow suppression mechanism is selected according to brightness and saturation information, and chrominance distortion and texture feature are used to eliminate shadow.4. An algorithm to extract accurate contours of multiple moving objects in color image sequences is proposed. The exponential filter is used to calculate the gradient magnitude of color image and the localization accuracy of local maximum of gradient in color image is increased, the gradient magnitude and the motion edges are used...