| 摘要 |
A method of sample adaptive offset (SAO) compensation of video data is disclosed, where pixels in the video data are classified into SAO categories, each SAO category representing a possible edge artefact and defining a corresponding offset value to be applied to pixels in the respective SAO category to compensate for the edge artefact. In the method, a plurality of SAO categories (200) is provided (110). The plurality of SAO categories includes one or more of the following: a first SAO category (101; 222a; 242a) exclusively representing a first edge artefact where a pixel (224) is at least almost equal to one of its neighbors (226) and distinctly lower than the other neighbor (228) in a given spatial direction, a second SAO category (102; 222b; 242b) exclusively representing a second edge artefact where the pixel (224) is at least almost equal to the other neighbor (228) and distinctly lower than the one neighbor (226) in the given spatial direction, a third SAO category (103; 232a; 252a) exclusively representing a third edge artefact where the pixel is at least almost equal to the one neighbor and distinctly higher than the other neighbor in the given spatial direction, a fourth SAO category (104; 232b; 252b) exclusively representing a fourth edge artefact where the pixel is at least almost equal to the other neighbor and distinctly higher than the one neighbor in the given spatial direction, and a combined SAO category (262, 272) jointly representing either the first and second edge artefacts or the third and fourth edge artefacts in combination, where the pixel is not equal to but close to a first one of the neighbors and distinctly lower or higher than a second one of the neighbors. The method further involves obtaining (120) a block of pixels (114) of video data (112). For pixels in the block of pixels (114), a current pixel is evaluated (130) with respect to its neighbors for a match with any of the SAO categories in the plurality of SAO categories (200). In case of a match (140), the offset value of the matching SAO category is applied (150) for the current pixel. |
