基于四叉树分割的变维矢量量化图像压缩算法  

Vector Quantization of Image Compression Algorithm Based on the Quad-tree Segmentation

作　　者：葛卫东[1] 黄瑞光[1] 

机构地区：[1]华中科技大学电子与信息工程系,武汉430074

出　　处：《计算机与数字工程》2008年第1期82-84,116,共4页Computer & Digital Engineering

摘　　要：传统的矢量量化压缩算法将图像分割为相同大小的编码块,该方法存在较多的冗余。为了提高矢量量化压缩算法的效率,提出一种基于四叉树分割的变维矢量量化图像压缩算法。首先对8×8的图像块进行编码,计算各图像块绝对误差之和,若大于预设的阈值,则将残差分为4等分再编码,重复该过程直到绝对误差之和小于预设的阈值或达到最小图像块。实验结果表明,相对于全搜索的矢量量化方法,在相同码率下,算法编码时间较短且重建图像质量较好。In conventional vector quantization,an image is divided into blocks that are all the same size.This uniform division could be redundant.In order to improve the efficiency of vector quantization algorithm,this paper proposes a vector quantization of image compression algorithm based on the quad-tree segmentation.By the method,an image block size of 8×8 will be encoded first.The sum of the absolute difference of each will be calculated after the encoding.If the SAD is greater than a given threshold,the residual image will be divided into four sub block of the same size and encoded again.Repeat this process until the SAD is less than the threshold value or the block size reach limit.The simulation results show that the proposed algorithm consumes less time to encode,while achieves better image quality with higher PSNR at the same bit rates than full search algorithm.

关 键 词：矢量量化 四叉树分割 多级 图像压缩 

分 类 号：TP317.4[自动化与计算机技术—计算机软件与理论]