Sample Adaptive Offset (SAO) is a sample-based filtering operation which is operated on a CTU basis.
It is applied right after the deblocking filter, if activated. Two SAO modes are specified: edge offset and band offset. The former is driven by local directional structures in the picture to be filtered, the latter modifies the… Read more »
The deblocking filter applies an adaptive smoothing filter operation across the boundaries of prediction and transform blocks inside the reconstructed picture.
The filtering strength depends on properties of the neighboring blocks, and the local decision whether to apply the deblocking filter depends on the difference between the edge sample values. If filtering across slice… Read more »
Example for deblocking of 2×2 CTBs.
Besides the original area of the picture from the test sequence and the corresponding decoded reconstruction, the samples along the prediction block and transform block boundaries which are modified by the deblocking filter are visualized. For comparison, the same region without the application of the deblocking filter is… Read more »