Compression artifact reduction with adaptive bilateral filtering

In this paper, we present a spatially adaptive method to reduce compression artifacts observed in block discrete cosine transform (DCT) based image/video compression standards. The method is based on the bilateral filter, which is very effective in denoising images without smoothing edges. When applied to reduce compression artifacts, the parameters of the bilateral filter should be chosen carefully to have a good performance. To avoid over-smoothing texture regions and to effectively eliminate blocking and ringing artifacts, in this paper, texture regions and block boundary discontinuities are first detected; these are then used to control/adapt the spatial and intensity parameters of the bilateral filter. Experiments show that the proposed method improves over the standard non-adaptive bilateral filter visually and quantitatively.