Abstract: We suggested a shape descriptor named Distance Ratio Context(DRC) which is based on the distance betwecn sampled points and the centroid of the object. hhis descriptor has the properties of invariant to scaling and translation essentially and can be calculated easily. It's also invariant to deformation and distortion in some ways and can discriminate different shapes effectively. The dynamic programming algorithms were used to measure the distance between DRCs and this mechanism solved the problem of start point choosing on the object contour. hhe experiments in kimia's-99 shape dataset show that this approach, used in image retrieval of shape with a single closed contour, can get favorable results.

Key words: Shape recognition, Shape retrieval, Distance ratio contexts, Dynamic programming