題名: Automatic rotational symmetry determination for shape analysis 作者: J. J. Leou;W. H. Tsai
貢獻者: Department of Information Communication
關鍵詞: Order of rotational symmetry;Average shape radius;Difference radius
function;Central moment function;Zerocrossings;Zerotouchings;Distance-weighted correlation;Similarity measure
日期: 1987-02
上傳時間: 2009-11-25T02:30:48Z 出版者: Asia University
摘要: The determination of the rotational symmetry of a shape is useful for object recognition and shape analysis in computer vision applications. In this paper, a simple, but effective, algorithm to analyse the rotational symmetry of a given closed-curve shape S is proposed. A circle C with the centroid of S as the circle center and the average radius of S as the circle radius is superimposed on S, resulting in the intersection of C and S at a set of points. By theoretical analysis, the relationship between the order Ns of the rotational symmetry of S and the number of intersection points between C and S is established. All the possible values for Ns are determined. And finally Ns is determined by evaluating the similarity between S and its rotated versions. In the proposed algorithm, only simple pixel operations and second-order moment function computation are involved. Several problems caused by the use of discrete image coordinates are analysed and solved for correct decision-making in the algorithm. Good
experimental results are also included.
