A Rotation Invariant Shape Representation based on Wavelet Transform

This paper introduces an object shape representation which provides similarity search for databases with a large number of images. The proposed algorithm uses the following techniques: 1) the complex-valued wavelet transform to utilize the phase information, 2) the translation-invariant wavelet representation to normalize the shape orientation. Experimental results show that the proposed algorithm be able to normalize shape orientation more accurately than the normalized Fourier descriptors[1] and has better performance in similarity search than the planar curve descriptors[2].