Efficient rounding for deblocking

摘要

The present disclosure relates to deblocking filtering which is applicable to smoothing the block boundaries in an image or video coding and decoding. In particular, the deblocking filtering is either strong or weak, wherein the clipping is performed differently in the strong filtering and the weak filtering.

主权项

1. A filtering method for applying a deblocking filter to a current block of an image, the filtering method comprising:
judging, by a processor, whether a strong filter or a weak filter is to be applied to a boundary between the current block and a neighboring block adjacent to the current block; calculating a linear combination of current samples in the current block and adjacent samples in the neighboring block, the current samples and the adjacent samples forming a line of samples; shifting the linear combination right by a predetermined number of bits; and clipping the shifted linear combination to generate a filtered sample of the filtered current block, wherein the clipping for the strong filter is controlled by a first clipping parameter and the clipping for the weak filter is always controlled by a second clipping parameter regardless of any other condition, the first clipping parameter and the second clipping parameter depending on a strength of the boundary but having a different value with each other.