Abstract: To solve the fuzzy phenomenon of fusion images,an adaptive image fusion algorithm based on nonsubsampled contourlet transform(NSCT) was proposed. The good properties of the contourlet transform and the nonsubsampled contourlet transform were discussed. After the original images were decomposed by NSCT, the low-frequency images were fused by the low-frequency changing rate and uniformity. When the changing rate difference between the low-frequcncy images was lower than the threshold, the changing rate was selected for making decision; otherwise the uniformity was used to make decision. The high-frequency images were fused by the high frequency contrast to make decision. Afto the image was fused, the entropy, relative error and average gradient were used to evaluate the fusion performance.The results show the adaptive fusion algorithm based on the nonsubsampled contourlet transform(NSCh) obtains better fusion performance.

Key words: Image fusion, NSCh, Changing rate, Uniformity, Contrast