Abstract:

An fusion algorithm for synthetic aperture radar (SAR) and panchromatic images based on multi-level threshold segmentation and the nonsubsampled Contourlet transform(NSCT) is proposed. Firstly, multi-level threshold segmentation is done for the despeckle SAR image, and the measurement named ratio of region mean(RRM) is presented to divide the SAR image into several regions. Then the NSCT is performed on the despeckle SAR image and the panchromatic image at different scales and directions. The low-frequency coefficients are fused with the region-based fusion scheme according to the RRM, and the high-frequency coefficients are fused with the windows-based rules and region-based rules. Finally the fused coefficients are reconstructed to obtain the fused image. Experimental results show that the fused image can not only preserves the spatial resolution of the panchromatic image but also effectively join the target information of the SAR image. The algorithm performs significantly better than the wavelet transform and the pixel-based NSCT.