Wavelet-Based Medical Image Registration for Retrieval Applications

In this paper, a novel, fully automatic, multiscale wavelet-based image registration technique is proposed for image retrieval applications. We present a fast 2-D rigid registration scheme for retrieval applications. Here, the use of multiscale wavelet representation with mutual information (MI) is expected to facilitate matching of important anatomical structures at multiple resolutions. We propose to use a dyadic grid in the parameter search space for efficient computation in the multiscale domain. The proposed approach has several novel aspects including the use of MI in multiscale wavelet domain and variable bin sizes for each level of decomposition. The technique is also tested under varying noise levels. The results show high efficacy of the proposed approach.