A one-pass algorithm for local symmetry of contours from chain codes

Abstract

This paper presents a one-pass algorithm for computing the local symmetry of contours from their chain code representation. This algorithm embeds the local symmetry deficiency (LSD) computation into our chain codes extraction process. The existing algorithms need to extract chain codes first and use them as input to compute LSD. The new algorithm uses a binary image as input and can complete the code extraction and the LSD computation in one pass. It can also extract multiple contours in an image in one pass. The algorithm is suitable for parallel implementation.