矩形子块定长约束分区适应快速AWT人像压缩

Fix-Length Constrained and Two-Area Fitted Portrait Compression Via Fast AWT of Rectangular Sub-Blocks

针对“居民身份证照片管理系统”中图象压缩软件的研制,本文提出了一种矩形子块定长约束分区适应快速AWT人像压缩编码方法,其特点是:采用矩形子图象与人像的相关性匹配;利用一维Hadamard变换(HT)计算二维Walsh变换(WT),速度快;面部与背景区域分别处理,视觉效果好;能自动适应不同的图象特性,在一定的主观质量下有效地约束总码长,保证压缩比CR≥7∶1。

A fast adaptive compression method for portrait data by 2D Walsh transform of rectangular sub-blocks is presented in this paper. It gives good image quality when the compression ratio≥7 : 1, whereas the speed matches that with the DPCM method.