Abstract:

Due to the shiftinvariance, nonsubsampled contourlet transform (NSCT) can accurately detect the edge orientation. However, traditional NSCT still reflects on pseudo-edge in the test result because of the improper selected fixed threshold. The dual threshold is adopted to filter the modulus maximum in the high-frequency sub-band, and two matrices are obtained as link compensation in order to decrease the pseudo-edge. Owing to the structural characteristics of NSCT coefficient, there is also ample edge information in low-frequency sub-band, and then a Canny operator is used to detect the low-frequency sub-band. The simulation results show that there are abundant highfrequency sub-band details, accurated edge orientation, and clear texture, based on the method of modulus maxima of dual threshold, and the Canny operator detects lowfrequency image edge stability, figure integrity and continuation, and the fused image can control noise effectively and avoid pseudo-edge.