Since the SD-based detector depends on the motion-compensated image only, it may cause false positives in detecting various feathering artifacts. We hence propose an additional step to reduce the false positive rate of the first step by taking into account MAD values, MV correlation, and MAD correlation. As shown in Fig. 5, if the MAD of the current block is sufficiently small, i.e., , and the MAD and MV of the current block are highly correlated with those of its neighbors, i.e., , we determine that the current block has a reliable MV. Let be the -norm distance between the current MV and the component-wise median of MVs of its eight-connected blocks, while indicates the -norm distance between and the average MAD for the eight-connected neighbor blocks. In this paper, , , and are empirically set to 20, 5, and 5, respectively. Therefore, since this second decision step further examines the MV reliability independently of the motion-compensated image, it can effectively prevent the entire mode decision from being trapped in false positives.