Abstract:

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.

Key words: edge identification, DCT, blocking artifact