图像块状瑕疵消除及边缘作用的分析

块状瑕疵是基于离散余弦变换的图像压缩常见问题之一，会造成图像质量的明显退化. 文中提出一种新的块状瑕疵消除（解块滤波）方法. 通过对近期解块滤波中边缘图提取方法及其作用的分析，引入压缩数据块的类型判断标准进行分划并提取边缘图，采用自适应复合方法消除图像中块状瑕疵. 所有的计算都在压缩域中进行，因此对原始数据的压缩特性没有任何影响. 实验结果表明，与现有其他方法相比，该方法覆盖范围广，输出稳定，处理后图像视觉效果好.

Reduction of Blocking Artifacts and Analysis of Edge Map Contribution

Blocking artifacts are a major problem in discrete cosine transform (DCT)-based image compression algorithms, which degrades the image’s visual quality. In this paper, a new method of blocking artifact reduction is proposed. Contribution of edge maps in the deblocking filtering is analyzed. A criterion used to classify block types is introduced according to the distribution of DCT coefficients both in half-block-shifted image blocks and in the original source image blocks. Using such classification, an adaptive combination method is used to reduce blocking effects. Since all computation is performed in the DCT domain, compressibility of the original image is not affected. By comparing with some existing methods, the experiment results verified effectiveness and robustness of the proposed method.