An improved randomized algorithm for detecting ellipses based on least square approach
Huajun Feng · Journal of Zhejiang University(Engineering Science) · 2008
An improved randomized ellipse detection algorithm based on least square approach was proposed to enhance the efficiency and accuracy of ellipse detection in digital images.This algorithm randomly selects three edge points in the image,and then uses least square approach to fit all the edge points in three windows,which are defined by the three edge points.The forth edge point is randomly selected to judge whether a possible ellipse exists in the image.Utilizing the characteristic of direct least square fitting of ellipse,an iteration process of edge point collecting and ellipse refitting of possible ellipse was introduced to extract the final ellipse's parameters.Artificial images with different levels of noise and nature images containing incomplete ellipses were employed to test this algorithm.Experimental results show that the improvements are notable.Compared with the original algorithm,the proposed algorithm reduces the dependence on arguments of detection algorithm,and enhances the speed,stability and accuracy of ellipse detection,while preserves the anti-noise ability of the original algorithm.