Coefficient coding harmonization in HEVC
Coefficient coding for transform units (TUs) during high efficiency video coding (HEVC), and similar standards, toward simplifying design while enhancing efficiency. Elements of the invention include coefficient coding for TUs with up-right diagonal scans being modified, and selectively applying multi-level significance map coding.
1. An encoding device, comprising:
circuitry configured to:
apply, as a condition that diagonal scan is applied to an 8×8 transform block of a plurality of transform blocks, diagonal scan to the 8×8 transform block including four 4×4 sub-blocks,
wherein the four 4×4 sub-blocks within the 8×8 transform block are diagonally scanned, and the diagonal scan is applied inside each of the 4×4 sub-blocks; and
execute unified multi-level significance map encoding on each of the plurality of transform blocks including the 8×8 transform block that has the diagonally scanned four 4×4 sub-blocks.
2. The encoding device according to claim 1 , wherein the 8×8 transform block is formed by recursive splitting a coding block as block partitioning.
3. The encoding device according to the claim 1 , wherein the circuitry is further configured to:
determine whether the plurality of transform blocks is scanned with one of a vertical scan, a horizontal scan, or the diagonal scan;
execute single level significance map encoding for each of the plurality of transform blocks based on the determination that the plurality of transform blocks is scanned with one of the vertical scan or the horizontal scan; and
execute the unified multi-level significance map encoding for each of the plurality of transform blocks based on the determination that the plurality of transform blocks is scanned with the diagonal scan.
4. A method, comprising:
applying, as a condition that diagonal scan is applied to an 8×8 transform block of a plurality of transform blocks, diagonal scan to the 8×8 transform block including four 4×4 sub-blocks,
wherein the four 4×4 sub-blocks within the 8×8 transform block are diagonally scanned, and the diagonal scan is applied inside each of the 4×4 sub-blocks; and
executing unified multi-level significance map encoding on each of the plurality of transform blocks including the 8×8 transform block that has the diagonally scanned four 4×4 sub-blocks.
5. The method according to claim 4 , wherein the 8×8 transform block is formed by recursive splitting a coding block as block partitioning.