What is more, the metric of this prediction method is co-called SATD which served as the valid feature in our experiment.
For a flat region, the accuracy of prediction can be higher, so the value of SATD can be smaller.
To further confirm the feature of SATD valueshave a close relationship with the split process of CU optimal depth level, we encode the first 20 frames of the standard test video sequence BQTerrace and recode the minimum value of SATD in HM 10.
From the above figures, we can see clearly that the CUs corresponding with the smaller values of SATD have the smaller possibility to be split, inversely, those CUs with the bigger values of SATD have the higher possibility chance to be split.
For a given CU block, the values of SATD and GDS entropy of this block can be calculated and then the path can be traced from the root node to the leaf node.