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Mode-Dependent Directional Transform (MDDT) in JM/KTA

2009-09-22 KTA 15 Comments Views(13,620)

The intra prediction in H.264/AVC is a type of spatial domain directional prediction, which means different intra prediction modes represent different prediction directions, such as horizontal, vertical, and diagonal. An intra-coded MB can be partitioned into 4×4, 8×8, or 16×16 intra prediction blocks. The 4×4 and 8×8 intra prediction blocks have nine prediction directions, respectively, and the 16×16 block has four. Hence, totally 22 (9+9+4) intra prediction modes are used in H.264/AVC. The residue usually has high energy along the direction of prediction, as edges are more difficult to be predicted than smooth areas.
Mode-dependent directional transform (MDDT) was proposed to compact the residue produced by intra prediction. It consists of a series of pre-defined separable transforms; each transform is efficient in compacting energy along one of the prediction directions, thus favoring one of the intra modes. The type of MDDT is coupled with the selected[......]

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