基于SPIHT压缩编码的SAR图像传输容错算法

合成孔径雷达(SAR)系统工作时产生的大量数据需要压缩传输,多级树集合分裂(SPIHT)算法性能优越但对信道噪声敏感,需要必要的容错机制.提出了一种噪声信道中传输SAR幅度压缩图像的容错算法,称为LLCH(LL coefficients hiding)算法.该算法对SPIHT编码后的码流进行基于编解码过程的数据分组,保证发生误码后解码端可重新同步;将码流中低频、次低频系数分组嵌入高频各过程末尾数据分组进行数据隐藏,达到保护重要系数的目的;对损伤或丢失的高频系数,利用父子节点间系数的相关性进行线性内插恢复.实验结果表明该算法在较小的冗余开销下,有效提升了复原图像的质量.

Error resilience algorithm for SAR image transmission based on SPIHT coding

Synthetic aperture radar (SAR) systems produce large amounts of data which needs to be compressed and transferred.SPIHT compression algorithm performance superior,but the coded images have fragile visual quality when transmitted across the noisy channel.An error-tolerance mechanism is necessary.An error-resilience algorithm called LL coefficients hiding (LLCH) for transmission of synthetic aperture radar (SAR) amplitude compression images in noisy channel is presented.The proposed method partitions data based on the coding process after the set partitioning in hierarchical tree (SPIHT's) coding process,to ensure that the decoder can re-synchronize after the error occurs.The most significant low frequency and sub-low frequency coefficients are embedded into the end of high frequency data packets to achieve the purpose of protecting the important coefficients.For the high frequency coefficients of damage or loss,linear interpolation is used to recover the coefficients rely on the correlation between subbands.The experimental results show that the algorithm can effectively improve the quality of the restored image under the tiny redundancy cost.