波段排序的高光谱影像3维混合树编码方法  

Hyperspectral image coding with band ordering and 3D hybrid tree

作　　者：王相海[1,2] 解天[1] 宋传鸣[1] 张智迪 

机构地区：[1]辽宁师范大学计算机与信息技术学院,大连116029 [2]辽宁师范大学自然地理与空间信息科学辽宁省重点实验室,大连116029

出　　处：《中国图象图形学报》2014年第8期1228-1236,共9页Journal of Image and Graphics

基　　金：国家自然科学基金项目(41271422);高等学校博士学科点专项科研基金项目(20132136110002);辽宁省博士科研启动基金项目(20121076);辽宁省教育厅科学研究一般项目(L2011192;L2013405;L2013406);智能计算与信息处理教育部重点实验室(湘潭大学)开放课题(2011ICIP06)

摘　　要：目的高光谱影像压缩的关键技术是对空间维和光谱维的去相关性。根据高光谱影像数据结构的特点,如何有效去除其空间相关性与谱间相关性是高光谱影像压缩中至关重要的问题。对高光谱影像进行编码时,3维小波变换是极为有效的去除冗余的方法。因此提出了一种通过波段排序并结合3维混合树型结构对高光谱影像3维小波变换系数进行编码的算法。方法首先,将高光谱影像按照自然波段顺序进行波段分组,并对每组影像进行相邻影像的谱间相关性统计;其次,对相关性较弱的波段组,建立以影像波段序号为顶点、影像相关性系数为边的完全图,对这个完全图求其最大汉密尔顿回路。按照求得的最大汉密尔顿回路顺序对该波段组进行重新排序,从而提高波段组的谱间相关性;在此基础上,对重新排序后的波段组进行3维小波变换,并通过3维混合树结构对3维小波变换系数进行零树编码。结果通过对大量AVIRIS型高光谱影像数据的仿真实验,验证了本文方法的有效性。对相关性较低的波段组,加入排序算法后,其解码影像与未排序时比,峰值信噪比有了一定的提高。通过实验统计,算法平均用时2.7579 s。结论由于采用了对弱相关性波段组的重新排序机制,使得基于混合树结构的3维零树编码出现了更多有效的零树,在一定程度上提高了编码效率。通过实验统计算法用时,表明该方法以较小的时间代价获得了解码效果的提升。Objective The key technology in hyperspectral remote sensing image compressiom is to get rid of the spatial correlation and spectral correlation.According to the characteristics of the structure of data of hyperspectral remote sensing image,how to effectively remove the spatial correlation and spectral correlation in hyperspectral image compression is a crucial problem.For hyperspectral remote sensing image,in the image coding,wavelet transform is a very effective method to remove redundancy.3 D wavelet transform can effectively remove the spatial correlation and spectral correlation of hyperspectral image.Therefore,this paper proposes a coding algorithm based on band ordering and 3D hybrid tree.Method First,the hyperspectral remote sensing image is divided into groups based on natural spectral order,each group contains 16 continuous spectral bands.Second,in each band group,the sum of the spectral correlation of all the adjacent bands is calculated.If the correlation value is less than a given threshold,a complete graph is structured on the basis of the group of bands.In the complete graph,each apex represents a band,so there are 16 apexes in the graph,and each side of the complete graph represents the spectral correlation value of two bands in the group.Then,the max Hamilton loop of the complete graph is searched for,and the group of bangs is reorderd based on the max Hamilton order to improve the correlation value of the band group.On the basis of the above,the reordered group of bands is given a 3D wavelet transform,and 3D hybrid tree coding algorithm is used to encoded the 3D wavelet transform coefficients.As to those band groups whose sum correlation values are greater than the given threshold,their band order does not have to be reordered.3D wavelet transform will be given to these band groups directly,and then wavelet transform coefficients will be encoded by the 3D hybrid tree coding algorithm.Result First,reordering the band groups with a relatively small correlation value can improve the efficiency of 3

关 键 词：高光谱影像编码 谱间相关性 波段排序 汉密尔顿回路 3维小波变换 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]