Wavelet-Based Multi-level Object Retrieval In Contour Images

In this paper we present a novel approach to shape similarity estimation. The target application is content-based indexing and retrieval over large image databases. The technique is based on wavelet decomposition and uses polygon approximation over several scales. This technique uses simple features (aspect ratio, angles, distances from the centroid, distance ratios and relative positions) extracted at high curvature points. These points are detected at each level of the wavelet decomposition as wavelet transform modulus maxima. The experimental results and comparisons show the performance of the proposed technique. This technique is also suitable to be extended to the retrieval of 3-D objects.