US 9,363,511 B2 · Method and apparatus for Intra mode coding in HEVC

Abstract

A method and apparatus for Intra prediction mode encoding or decoding based on multi-level most probable modes (MPMs) are disclosed. In one embodiment according to the present invention, the method and apparatus for encoding or decoding Intra prediction mode for 4×4 prediction unit (PU) use 19 Intra mode candidates to have full directional coverage or 35 Intra mode candidates as used by 8×8, 16×16 and 32×32 PUs. In another embodiment of the present invention, three MPMs are used to code the Intra modes. Various methods to derive the three MPMs based on the Intra modes of neighboring blocks are disclosed. In yet another embodiment of the present invention, the coding method for the remaining modes comprises fixed length coding. In addition, variable length coding for the remaining modes are also disclosed.

Claims20

Dependent claims

A method performed by a CODEC (coder/decoder) for Intra prediction mode processing based on multiple MPMs (most probable modes) in HEVC (High-Efficiency Video Coding), the method comprising:

using a processor operating on a decoding side of the CODEC to perform the steps of:
determining a first Intra mode associated with a top block of a current block;
determining a second Intra mode associated with a left block of the current block;
deriving three MPMs based on the first Intra mode and the second Intra mode;
and
processing a current Intra mode associated with the current block according to the three MPMs;
wherein if the first Intra mode and the second Intra mode are the same, then:
a first MPM of the three MPMs is set to the first Intra mode or the second Intra mode;
if the first MPM is DC mode, then a Vertical mode and Planar mode are assigned to a second MPM and a third MPM, respectively;
and
if the first MPM is the Planar mode, then the Vertical mode and the DC mode are assigned to the second MPM and the third MPM, respectively.

8 more elements

A method performed by a CODEC (coder/decoder) for Intra prediction mode processing based on one or more MPMs (most probable modes) in HEVC (High-Efficiency Video Coding), the method comprising:

using a processor operating on the decoding side of the CODEC to perform the steps of:
determining a first Intra mode associated with a top block of a current block;
determining a second Intra mode associated with a left block of the current block;
deriving said one or more MPMs based on the first Intra mode and the second Intra mode, wherein the first Intra mode and the second Intra mode are selected from a first set consisting of Intra mode candidates;
and
processing a current Intra mode associated with the current block according to a coding method for a second set consisting of remaining modes of the first set not included in said one or more MPMs, wherein the coding method includes fixed-length coding;
wherein, if the first Intra mode and the second Intra mode are the same, then:
a first MPM of the one or more MPMs is set to the first Intra mode or the second Intra mode;
if the first MPM is DC mode, then a Vertical mode and a Planar mode are assigned to a second MPM and a third MPM, respectively;
and
if the first MPM is the Planar mode, then the Vertical mode and the DC mode are assigned to the second MPM and the third MPM, respectively.

8 more elements

Dependencies are inferred from the claim text.

Method and apparatus for Intra mode coding in HEVC

Life of this patent

Method and apparatus for Intra mode coding in HEVC

Life of this patent

Abstract

Claims20