机载遥感系统超光谱图像分层近无损压缩

Layered Near-lossless Compression Scheme of Hyper-spectral Image in Airborne Remote Sensing System

针对机载遥感系统超光谱图像实时压缩与传输的需求,分析了超光谱图像位平面的相关特性并设计了超光谱图像分层近无损压缩方案。高位采用防误码的DPCM去相关,依据图像复杂度实时调节压缩比以适应传输带宽;低位按一致性准则进行四叉树划分并取均值,均匀量化残差图像后进行编码,得到混合码流。算法简单有效,实际压缩比和预设压缩比差别不超过5%。压缩比接近10时,复原图像PSNR值大于33,高位位平面平均相似度不低于0.98。

For real-time compression and transmission of hyper-spectral image in airborne remote sensing system, a new layered near-lossless compression scheme was proposed according to the analysis of correlations among bit-planes. An error-prevention I）PCM was used in spectral decorrelation of higher bit-plane, and then compression ratio control strategy was applied based on the complexity of residual image. Lower bit-plane was uniformly quantified after quadtree split- ting and removing mean. The algorithm is easy to realize and can effectively control the compression ratio. The diffe- rence between the practical compression ratio and the setting compression ratio is less than 5%. The PSNR is bigger than 33 and the XSD of higher-bit reconstructed image is bigger than 0. 98 when the compression ratio is about 10.