边缘指导的BDCT压缩图像的后处理算法
An Edge-Based Adaptive Post-Processing Technique for Block-Based Discrete Cosine Transform Coded Images
-
摘要: 基于BDCT的压缩图像由于频域的量化使重建回的图像出现“块失真”和“振铃”效应,严重影响了压缩图像的质量,提出一种针对这两种失真分别进行处理的后处理算法.首先,根据压缩图像块的属性把像素块分为不同的种类,针对不同的块采用3种不同的模式来去除“块失真”;然后,在边缘检测结果的指导下,对不同的区域采用不同的滤波器进行滤波,来消除“振铃”.大量的实验结果表明,该算法在主观视觉效果和客观标准评价上都取得了良好的效果.Abstract: In this paper, an edge-based adaptive post-processing technique is proposed, with the aim to remove the blocking artifacts as well as ringing artifacts especially in the situation where edges in the coded image degrade seriously. The proposed algorithm takes two main steps: deblocking step and deringing step. In the deblocking step the blocks are classified as low frequency or high frequency blocks first, then different methods will be adopted to remove the block artifacts according to the flatness along the block boundary. In the deringing step, the image is divided into three parts: main edge vicinity area, detail edge area and flat area according to the result of edge detection. Then different filters will be used to different areas. In this way, both the artifacts beside the strong edge and detail edge will be removed and it will not introduce new blur. Simulation results show that the subjective perceived quality as well as objective evaluation is improved.
下载: