Simple and Effective Filter to Remove Corner Outlier Artifacts in Highly Compressed Video

We propose a detection method of corner outlier artifacts and a simple and effective filter in order to remove the artifacts in highly compressed video. We detect the corner outlier artifacts based on the direction of edges going through a block corner and the properties of blocks around the edges. Based on the detection results, we remove the stair-shaped discontinuities, i.e., corner outlier artifacts, using the neighboring pixels of the corner outlier artifact in the spatial domain. Simulation results show that the proposed method improves, particularly in combination with a deblocking filter, both objective performance and subjective visual quality.