Affine Invariant Shape Matching using Histogram of Radon Transform and Angle Correlation Matrix

Abstract

An affine invariant shape matching descriptor using the histogram of Radon transform (HRT) and the dynamic time warping (DTW) distance is proposed. Our descriptor based on the Radon transform is robust to shape rotation, uniform scaling, and translation. For non-uniform scaling and shearing, our descriptor has a nonlinear sparse and dense distortion relative to the angle coordinates. Therefore, we apply DTW on a cost matrix to be robust to these transformations. This cost matrix is defined as an angle correlation matrix based on the product of two matrices only. Moreover, based on the beam search algorithm, we speed-up the time complexity of our method. Experimental results show that our approach is fast to compute and competitive compared to well-known descriptors.