Abstract: In order to solve the problem of directional finiteness in wavelet transform,and reduce the redundancy of Laplacian pyramid decomposing in contourlet transform,an image fusion algorithm for regional gradient selection mean is proposed,based on the waveletbased contourlet transform(WBCT).In this algorithm,weighted mean rules are employed for low frequence while for high frequence,the regional gradient is calculated with the use of selection average rules.Evaluation of the experimental results according to objective criteria including spatial frequence,cross entropy and deviation demonstrates that the fusion algorithm based on WBCT is better than the one based on wavelet transform or contourlet transform with the same fusion rules.

Key words: wavelet-based contourlet transform; image fusion; fusion rule; regional gradient selection mean