Block Artifact Reduction Based on Pixel Classification Using Binary Edge Map

Block artifact is one of the visually annoying problems that usually exist in low-bit-rate compression images or videos. In this paper, we propose a simple but effective method to reduce block artifact based on pixel classification in spatial domain. We classify each pixel into two classes: smooth region and edge region, by using a binary edge map from the edge detection process. An adaptive offset smoothing with the binary edge map is applied to reduce grid noise at block boundaries. Moreover, an extra edge-preserved filter is used to remove block artifacts at edge region. Our experiments show that the proposed method can reduce block artifact effectively more than block-based classification methods.