基于直方图变换的多光谱图像3D SPIHT压缩编码算法

提出了新的多光谱图像压缩方案,直方图变换的三维分层树的集划分(3D SPIHT)压缩编码算法。基于多光谱图像的成像特点,在去相关之前,提出一种可逆的直方图变换方法对多光谱各波段图像灰度值进行调整,来提高各波段间的相关性,然后再对变换后的图像利用K_L和二维小波变换去除谱间冗余和空间冗余。小波编码采用两种编码方案:3D_SPIHT以及对它进行改进后的三维位平面的SPIHT算法,并对两者进行了比较。实验表明,采用直方图变换的这两种方法都获得了良好的效果,比没变换前有更好的图像质量和压缩性能。

3D SPIHT algorithm of the multispectral image based on histogram modify

A new multispetral image data compression algorithm(histogram modification/3D SPIHT coding algorithm) was proposed,which can efficiently reduce the spectral and spatial redundancies by applying Karhunen-Loeve transform(KLT) and two-dimensional discrete wavelet transform(2D DWT).The novelty of the algorithm is that it proposed a reversible histogram modify to convert the gray values of the multispectral image before decorrelation.Two schemes to encode the wavelet coefficient were proposed.Numerous experiments on a seven-band thematic mapper images show that the reconstructed images of the two schemes after using the histogram modification exhibit a better quality and higher compression ratio than the algorithms without histogram transform.