Matrix-based intra prediction with asymmetric binary tree

Abstract

Several methods are described to jointly use the ABT (Asymmetric Binary Tree) partitioning mode and Matrix-based Intra Prediction (MIP). In a first embodiment, we propose to forbid the use of the MIP intra prediction mode, for block sizes that are resulted from ABT partitioning. In a second embodiment, we propose to allow the MIP intra prediction for block sizes not equal to a power of two in width or height, by extending the block before MIP and crop the predicted block to the original size after MIP. In a third embodiment, we propose to adapt the down-sampling of the boundary reference samples and the up-sampling of the reduced predicted blocks, to the block sizes introduced by ABT partitioning. In a further embodiment, we set the reduced predicted block to size 8×8 in any case the initial block size is 8 and larger than 8 in a direction.