FFT-based coding algorithm with accurate rate control for space-borne SAR complex images
Zhensong Wang · National Remote Sensing Bulletin · 2009
With the rapid development of SAR missions,on-board SAR image processing is required. SAR could obtain much higher resolution images than ordinary radar,and it is very necessary to compress data before transmission,since the generated SAR data volume is much higher than the data bandwidth of the satellite downlink. In this paper,an efficient compression algorithm with accurate rate control is proposed based on SAR complex image characteristics. The algorithm applies an adaptive weighted quantizer on 2D-FFT coefficients,and then uses entropy encoder to code the quantized coefficients. Based on the es-tablished R-Q and MPE-Q statistical models,an accurate rate control is developed. We measure the compression performance with PSNR and MSSIM (Mean Structural Similarity) of the magnitude image and MPE (Mean Phase Error). With four SAR complex images compressed at different ratios,the compression performance is analyzed and compared with other algorithms including JPEG2000,H.264,etc. Experimental results show that the proposed algorithm outperforms other algorithms,and the rate control obtains high accuracy.