SAR Image Compression Based On Subband

As the representation of Microwave Sensing, Synthetic Aperture Radar has the ability to take images in all the day and all the weather conditions, and SAR systems achieve good azimuth resolution, so it has been widely used in both military and civilian field. But in a SAR image system composed of acquisition, transmission and reception, elementary requirement of image processing is how to compress images to meet our need, in this paper, we study the processes of SAR image compression, and validate it by experimental results.Subband coding has become quite popular for the source coding of speech. The subband coding of image extends from this kind of concept. The basic idea of subband coding is: divide image into high and low frequency-domain partition by using digital filter banks, then select different coding algorithm according to different subband.Block truncation coding (BTC) is a fast moment-preserving lossy image compression technique, it has the advantage of simple operations and it doesn't require complicated mathematics computations. BTC has been used for many years for coding digital images for purposes of transmission and storage.The decomposition and synthesis of image based on the perfect-reconstruction filter banks are analyzed in this article; then a novel PBTC (Pre-processing Block Truncation Coding) method is presented to improve the effect in image compression based on the different significance between the subband by decomposition of image, and is applied to SAR Image compression. Results clearly show that PBTC is superior to the method without Pre-processing on real-time transmission and achieving better imaging quality.