超光谱图像的三维小波嵌入零块压缩编码  

Hyperspectral Image Compression Using Three-Dimensional Wavelet Embedded Zeroblock Coding

作　　者：吴家骥[1] 吴振森[2] 吴成柯[3] 

机构地区：[1]西安电子科技大学智能信息处理研究所,陕西西安710071 [2]西安电子科技大学理学院,陕西西安71007 [3]ISN国家重点实验室(西安电子科技大学),陕西西安710071

出　　处：《软件学报》2007年第2期461-468,共8页Journal of Software

基　　金：国家自然科学基金Nos.60607010;60672125;60371020;60532060~~

摘　　要：超光谱图像作为一种三维图像,其海量的数据导致在有限带宽信道上传输和存储非常困难,必须对它进行有效的压缩编码.提出了一种基于非对称三维小波变换(3D wavelet transform,简称3DWT)和三维集合块分裂的超光谱遥感图像压缩方法.因为大多数超光谱图像在各个方向上具有非对称的统计特性,所以利用非对称三维小波变换去除图像的谱间和空间冗余.与传统的对称三维小波变换相比,非对称的三维小波变换能够更有效地去除相邻谱段间的冗余.提出了一种改进的3DSPECK(3D set partitioning embedded block)算法——非对称三维集合分裂块算法(asymmetric transform 3DSPECK,简称AT-3DSPECK),并被用于编码变换后的系数.根据变换系数的能量分布特点,三维零块分裂和三维octave子带分裂方法被有效地结合在所提出的AT-3DSPECK算法中.为了优化率失真和加速编码速度,也给出了一种零块优化排序的快速算法.实验测试表明:AT-3DSPECK算法的平均PSNR(peak signal to noise ratio)分别比AT-3DSPIHT(asymmetric transform 3D set partitioning in hierarchical trees)和3DSPECK算法高0.4dB和1.4dB.此外,AT-3DSPECK还具有比零树算法更快的编码速度.As 3D images, hyperspectral images result in large sized data sets. The storage and transmission of large volumes of hyperspectral data have become significant concerns. Therefore efficient compression is required for storage and transmission. In this paper, a new hyperspectral remote sensing image compression method based on asymmetric 3D wavelet transform and 3D set partitioning scheme is proposed. Because most hyperspectral images have asymmetric statistical properties in all directions, an efficient asymmetric 3D wavelet transform （3DWT） is used to reduce redundancies in both the spectral and spatial dimensions. Compared with traditional symmetric 3D wavelet transform, asymmetric 3D wavelet transform can more efficiently remove the correlation between the adjacent bands. A modified 3DSPECK （3D set partitioning embedded block） algorithm, AT-3DSPECK （asymmetric transform 3DSPECK）, is proposed and used to encode the transformed coefficients. According to the distribution of energy of the transformed coefficients, the 3D zeroblock partitioning algorithm and the 3D octave band partitioning scheme are efficiently combined in the proposed AT-3DSPECK algorithm. To accelerate the speed and optimize the rate-distortion performance of the embedded bit stream, a fast algorithm of the optimal zeroblock sorting is given. Experimental results show that the proposed algorithm outperforms AT-3DSPIHT （asymmetric transform 3D set partitioning in hierarchical trees） and 3DSPECK by 0.4 dB and 1.4dB on the average PSNR （peak signal to noise ratio） respectively. Compared with popular zerotree approaches, AT-3DSPECK is faster in coding speed.

关 键 词：超光谱图像 三维图像压缩 嵌入编码 零块编码 小波变换 SPIHT(set partitioning in hierarchical trees) SPECK(set partitioning embedded block) 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]