Shape matching using a self similar affine invariant descriptor

In this paper we introduce a shape descriptor known as Self Similar Affine Invariant (SSAI) descriptor for shape retrieval. The SSAI descriptor is based on the property that two sets of points are transformed by an affine transform, then subsets of each set of points are also related by the same affine transformation. Also, the SSAI descriptor is insensitive to local shape distortions. We use multiple SSAI descriptors based on different sets of neighbor points to improve shape recognition accuracy. We also describe an efficient image matching method for the multiple SSAI descriptors. Experimental results show that our approach achieves very good performance on two publicly available shape datasets.