基于小波域降采样的低比特率图像压缩算法  

Low Bit-rate Image Compression Algorithm Based on Down-sampling in Wavelet Domain

作　　者：李庆忠[1] 谷娜娜[1] 刘晓丽[1] 

机构地区：[1]中国海洋大学工程学院,山东青岛266100

出　　处：《计算机工程》2013年第4期272-275,279,共5页Computer Engineering

基　　金：国家"863"计划基金资助项目(2006AA09Z237)

摘　　要：针对无线传输背景下低比特率图像压缩存在的模糊和振铃问题,提出一种基于小波域降采样和插值的高效图像压缩算法。在编码端,对图像进行小波变换,根据各高频子带特点对其进行自适应降采样处理,并采用基于小波树的小波差分缩减编码算法进行编码。在解码端,采用基于边缘方向的插值方法将解码的高频子带进行放大,对解码重建的图像采用基于强边缘的自适应滤波算法以消除振铃效应。实验结果表明,与基于空域降采样的图像压缩算法相比,该算法具有较高的图像解码质量,可有效抑制低比特率下重建图像的模糊和振铃问题。To overcome the image blurring and ringing effect problem encountered in low bit-rate coding of images for wireless transmission, an efficient image compression algorithm via adaptive down-sampling and interpolation in wavelet domain is presented. At the encoding end, the image is transformed to wavelet domain, and the high frequency subbands are down-sampled adaptively according to their characteristics. The down-sampled image is coded by the wavelet tree-based Wavelet Difference Reduction（WDR） algorithm. At the decoding end, the decoded high frequency subbands are enlarged by using an edge direction based interpolation method, and the reconstructed image is post processed by a strong edge based adaptive filter to eliminate the ringing effect. Experimental results show that compared with the spatial down-sampling based compression algorithm, the proposed algorithm possesses higher decoding quality of images at low bit-rate, thus effectively alleviates the image blurring and ringing effect.

关 键 词：降采样 图像压缩 图像插值 低比特率编码 小波变换 振铃效应 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]