Contour shape description based on an arch height function

摘要

A new method to extract contour features is proposed. For any contour C, a function, which we call Arch Height Function (AHF), is defined for each point and its value on C is computed. The set of AHF values is then used as a description of the shape of C. In particular, its local maxima, if they exist, correspond precisely to the cornerpoints of C. Besides, the method is computationally efficient as compared with the existing techniques of the contour feature extraction. The new method provides an effective and reliable tool for contour description, especially for angle detection. Some experimental results that demonstrate the adaptability and reliability of the AHF method are presented.