一种基于图象小波极值表示的减少方块效应的算法

针对低比特率JPEG压缩图象会产生严重的方块效应问题和根据后处理技术可有效地减少方块效应的认识,提出了一种新的基于图象小波极值描述的后处理算法。该算法根据解压缩图象方块效应在一级和二级小波变换系数中的极值特性，对位于图象背景区、平滑边缘区及阶梯状边缘区的方块边界的小波极值分别加以处理。实验结果表明，该算法能有效地减少方块效应，且能改善译码图象的信噪比和主观视觉质量。

An Algorithm for Reduction of Blocking Effects Based on Image Representation Using Wavelet Transform Extreme

Low bit rate JPEG compressed images demonstrate serious blocking effect. Post processing is an effective way to reduce the artifact blocking effects.A post processing algorithm based on image wavelet extreme representation is studied in this paper. It is noted that in the wavelet domain, blocking effect can display the artifact wavelet transform modulus maxima at block boundaries. To take account of reducing blocking effects and maintaining original image edges, the maxima corresponding to block boundaries in the different region of image are processed in different ways. Experimental results show that the proposed method can significantly reduce blocking artifacts and improve PSNR and visual quality.