The Research Of Image Compression Technology Based On Synthetic Aperture Rada

The purpose of this thesis is to improve the property of embedded zero-tree image compression coding algorithm in wavelet transform domain. In this paper, an improved zero-tree coding method based on wavelet transform is proposed, and put this improved method into Synthetic Aperture Radar compression coding application.The experiment results show the improvement is valid and high compression rate can be achieved.The improved algorithm consists parts showed belowChosen the more suitable Daubechies 9/7 orthogonal wavelet basis for the image transform.Used symmetric periodic extension method to compression coding and improve the compression quality after experimental analysis beyond expecting.It is necessary to modified the DPCM coding method, according to the distribution features of low frequency coefficients and human visual characters, when to reach high compression ratio.It can remove the compression visual redundancy effectively.Also change thresholds to the zero-tree quantization method at different directions of image and improve the image quality under the same ratio.