关键词: 椭圆拟合, 惯量矩, 概率密度, 形心主轴

Abstract: In digital image, Hough transform and least square method are unable to deal with ellipse fitting directly, need edge detection and so on, and the process is complex and needs large amount of calculation. Aiming at this problem, this paper puts forward a method of ellipse fitting by image inertia moment. Firstly, it selects the target in the image, converts color image to probability density grayscale; then, the center and inertia moments of principal axis are calculated, and it derives the angle of rotation and inertia moments of centroidal principal axis in the condition that inertia product is zero; finally, it acquires the ellipse parameters of semi-major axis and semi-minor axis according to the centroidal principal axis. Experiments in color image verify the effectiveness and robustness of the proposed method in fitting target ellipse.

Key words: ellipse fitting, moment of inertia, probability density, centroidal principal axis