Wavelet Transform for Partial Shape Recognition Using Sub-Matrix Matching

In this paper, we propose a method for 2D partial shape recognition under affine transform using the discrete dyadic wavelet transform invariant to translation well known as Stationary Wavelet Transform or SWT. The method we propose here is about partial shape matching and is based firstly on contour representation using the wavelet transform. A technique of sub matrix matching is then used to match partial shapes. The representation is based on three steps, the contour is first parameterized by enclosed area, the affine invariant feature is then calculated to finally determine the natural axis which enable to fix the starting point. The knowledge of the orientation of the natural axis enables to adjust the starting point on the contour between the query and the models in a given database. Furthermore, the method can selects a subset of useful invariant features for the matching step. A sub-matrix matching algorithm developed by (Saber et al., 2005)is then used to determine correspondences for evaluation of partial similarity between an example template and a candidate object region. The method is tested on a database of 5000 fish species, and the results are very satisfactory.