一种适于空间CCD图像压缩的SPIHT改进算法  

An improved SPIHT image algorithm for space TDICCD camera

作　　者：张柯[1] 杜丽敏[2] 李进[1,3] 韩双丽[1] 金龙旭[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]长春大学电子信息工程学院,吉林长春130022 [3]中国科学院研究生院,北京100039

出　　处：《光电子．激光》2013年第6期1219-1224,共6页Journal of Optoelectronics·Laser

基　　金：国家"863"高技术研究发展计划(863-2-5-1-13B)资助项目

摘　　要：针对传统遥感图像压缩多级树集合分裂排序(SPIHT)算法由于采用取决于图像内容的动态处理顺序而导致处理速度缓慢这一问题,提出一种适于空间时间延时积分(TDI)CCD相机图像压缩的SPIHT改进算法。首先,将小波变换后的图像分解成4×4块,同时对一个4×4块的一个比特平面所有比特进行编码。为了实现并行处理机制,SPIHT改进算法重组传统SPIHT算法的3个通道,然后采用并行和流水线作业的方式编码3个重组通道。实验结果表明,本文提出的压缩算法可以稳定正常的工作,具有良好压缩性能,平均信噪比(PSNR)性能与传统方法相当,而数据吞吐率远高于传统方法。在正常100MHz时,数据吞吐率达到120Mpixle,大大提高压缩算法的处理速度。SPIHT改进算法非常适合空间CCD相机图像压缩应用。In order to solve the problem of slow processing speed of set partitioning in hierarchical trees （SPIHT） due to its dynamic processing order that depends on the remote sensing image contents, an improved SPIHT image algorithm for space time delay integral CCD （TDICCD） camera is proposed in this paper. Firstly,a wavelet-transformed image is decomposed into 4×4 blocks and simultaneously all the bits are encoded in a bit-plane of a 4×4 block. In order to realize the parallel processing mechanism, the three passes of the traditional SPIHT algorithm are reorganized. The reorganized three passes are encoded in a parallel and pipelined manner. The experimental results show that the proposed compression al- gorithm can work stably and reliably and has good compressive property. Compared with the traditional methods,the performance of average peak signal-to-noise ratio （PSNR） for our method corresponds to that of the conventional approaches. However,it is superior to others for the throughput. The improved SPIHT algorithm can process 120 million samples per second at an operating clock frequency of 100 MHz,greatly improves the image algorithm speed and is very suitable for the application of image for space CCD camera.

关 键 词：空间时间延时积分(TDI)CCD相机 图像压缩 多级树集合分裂排序(SPIHT)算法 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]