感兴趣系数图像压缩编码算法

A Novel Image Coding Algorithm Based on Coefficients of Interest

根据遥感图像编码的特殊性,提出了一种感兴趣系数编码算法。对于给定码率计算遥感图像小波域系数的熵估计值,从而大致确定正常编码情况下图像编码所截取到的比特平面,在此基础上给出了感兴趣系数确定方案及提升幅度的计算方法。该算法与感兴趣区域编码方法不同,不需要在图像域指定感兴趣区域,系数提升幅度也不用提前指定,而且不必对所有子带的系数进行提升。该算法是任意区域的感兴趣区域编码的扩展和补充,但更为灵活、有效。仿真结果表明该算法可以有效保留遥感图像中小目标的信息,但图像总体质量略有下降。

A novel image coding algorithm based on coefficients of interest is proposed in terms of the special needs of remote-sensing images. When coding rate is given, the entropy estimate is calculated from the coefficients of the given image, so that the last coding bit-plane can be derived when the image is coded normally. The difference of the algorithm from the one for region-of-interest algorithm lies in that the region and the scaled value need not be preappointed, and the most important is that all the coefficients in bands are not scaled up, while the coefficients of interest and the scaled value are deduced from the given image in the algorithm. This algorithm can be thought as the generalization from the region-of-interest algorithm, which is smarter and more valid than the region of interest coding algorithm. The simulation and the experimental results show that the small targets in the remote-sensing images can be saved validly while the whole image quality decreases a little.