Fusion of multi-polarimetric SAR images using directionlets transform

An efficient SAR image fusion algorithm for multi-polarimetric images based on Directionlets transform is proposed. Directionlets transform is a new lattice-based multi scale analysis anisotropic multi-directional wavelet transform. Firstly, several polarimetric images can be decomposed into low frequency coefficients and high-frequency coefficients with multi scales and multi-directions using the Directionlets transform. For the low-frequency coefficients, the average fusion method is used. For the each directional high frequency sub-band coefficients, the directive contrast and the larger value of region variance information measurement is used to select the better coefficients for fusion. At last the fused image can be obtained by utilizing inverse transform for fused Directionlets coefficients. Experimental results show that compared with traditional algorithm, the proposed algorithm can get better visual effect and the significant information of original image like textures and contour details is well maintained.