| In this research, some novel modifications and modern applications of the Hough transform algorithms have been pursued. First, the dual points Hough transform algorithm was studied. Our approach optimises the R-Table of the prototype by using some statistics techniques in order to reduce the number of entries per index in the R-Table and make the entries inside the R-Table distribute evenly. Experimental results show that our method can both speed up the process and increase the recognition accuracy.; Second, a dominant point detection algorithm has also been studied. The reason for pursuing this study is that we can reduce the number of operations by employing dominant points as the features in the Hough transform process. Owing to the lack of appropriate dominant point detection algorithms for real scenes, a new dominant point detection algorithm has been proposed. Apart from the curvature points, we also defined the termination and intercept points on a digital curve as the dominant points since they indeed give useful information about the natures of the curves. A weighted mask is proposed for the initial detection. By using a look up table, all possible dominant points can be located efficiently. Experimental results show that our method achieves a better performance in terms of approximation error when compared with other methods.; After the development of the dominant point detection algorithm, we have developed a Hough transform algorithm that makes use of the dominant points as the corresponding features in tracking an object in a video sequence. The user inputs a user-defined object in the first frame. Then, an R-Table is built based upon the dominant points of the selected object. When the next frame is reached, the transformation parameters of the object can then be detected by using the Hough transform. Our proposed algorithm is capable not only to track the object under a continuous deformation, but also able to recognise the object under occlusion and recover the tracking when the object reappears in the video sequence.; Finally, a Hough transform algorithm that makes use of the color information as the corresponding features is studied. To start with, a color image is segmented into some regions with homogeneous colors by applying a watershed algorithm and a new region merging algorithm. The region merging algorithm merges regions based on the ideas of reducing the errors of the color differences, maintaining the uniformity of the color and controlling the minimum size of each region. (Abstract shortened by UMI.)... |
