一种灵活可靠的星载图像压缩编码技术

A Novel Image Compression Coding Scheme Designed for Satellite Application

针对星上图像数据量大、传输带宽有限、关键信息不能丢失、星地传输链路存在干扰和码流存在误码等问题,提出了一种分块可调的JPEG-LS压缩算法及满足一定误码率的信源检纠错编码方式。压缩算法对图像进行分块的同时通过在分块边缘使用梯度填充的方法避免了压缩比降低的问题。算法能够有效地控制误码的扩散,通过对不同分块采用无损/微损压缩模式组合的方式,既能保留敏感数据不丢失,又能获得较高的压缩比。通过实验分析对比3种典型的检纠错编码方法,从而得出适合星上应用环境的信源检纠错编码方式。

In satellite application,the volume of image data is large,the transmission bandwidth is limited,key information cannot be lost, there is interference to the transmission link and errors exist in the code stream. To address these issues, an improved block adjustable JPEG-LS compression algorithm and a suitable source error detection/correction coding method are designed. During image partitioning, the compression algorithm uses gradient filling method at each block edge to avoid reducing the compression ratio. The algorithm can effectively control the spreading of the errors,and by using lossless/little-loss compression mode in different blocks,it not only keeps the sensitive data lossless, but also achieves the high compression ratio. By comparing and analyzing three kinds of typical error detection/correction coding methods, the most suitable method for satellite application is obtained.