Low Bit Rate Compression for SAR Image Based on Blocks Reordering and 3D Wavelet Transform

Due to that there are a large number of similar characteristics in surface structure of the SAR image, a novel SAR image compression algorithm was proposed based on 3D wavelet transform after block reordering. This proposed algorithm consists of four successive steps: divide the image into sub-blocks with equal size, reorder the sub-blocks according to the similarity measured by weighted Euclidean distance to form 3D array, then 3D wavelet transform and 3D-SPIHT coding are employed for encoding. Experimental results of real SAR images show that the proposed method outperforms the traditional wavelet-based SPIHT in terms of PSNR, especially at the low-bit rate.