Abstract: This paper proposes a transform structure with arbitrary shape blocks for geometry block partitioning. A square coding block is split into two arbitrary shaped prediction blocks by geometry partitioning, which is more flexible than the partitioning method used in current video coding standards. In the current design, using a square transform block for combined square residual block is not reasonable and will affect transform efficiency. To further improve the transform structure, we propose that the two arbitrary shaped residual blocks are transformed separately with arbitrary shaped transform blocks. A turnover method is used to retain the correlation of residuals. Experimental results show that a bit rate saving of 1.16%~3.05% can be achieved.

Key words: geometry block partitioning, transform block, transform with arbitrary shaped block