AN EFFICIENT ALGORITHM FOR COMPUTATION OF SHAPE MOMENTS FROM RUN-LENGTH CODES OR CHAIN CODES

Moments are very useful for shape analysis. Zero- to third-order moments have been used for computer vision applications such as shape recognition and orientation. They can serve for composition of the well-known moment invariants used as desirable features as well as for the detection of the location and the principal axis direction of a shape. The shape is often represented by a binary image and its moments can be obtained by use of fast algorithms considering the shape as a discrete point array. In this paper a new algorithm based on the double-integral formulation is presented. The shape is considered as a continuous region and the contribution of boundary points is used for fast computation of shape moments. This method can be used to calculate moments from either the run-length codes or the chain codes of shape.