Intra prediction mode encoding/decoding method and apparatus for same

Patent metadata

Field	Value
Publication number	US-10091502-B2
Application number	US-201715799086-A
Country	US
Kind code	B2
Filing date	Oct 31, 2017
Priority date	Dec 21, 2010
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

An intra prediction method according to the present invention comprises the following steps: deriving neighboring prediction mode information from a left neighboring prediction mode and a top neighboring prediction mode; deriving an intra prediction mode for a target unit to be decoded, using the derived neighboring prediction mode information; and performing intra prediction for the target unit to be decoded, based on the intra prediction mode. According to the present invention, video encoding/decoding efficiency may be improved.

First claim

The invention claimed is:

1. A video decoding apparatus comprising:
an entropy decoding module to perform entropy-decoding on an input bitstream to derive quantized transform coefficients related to a target decoding unit;
an inverse-quantization module to perform inverse-quantization on the quantized transform coefficients to derive transform coefficients;
a prediction module to
receive and decode a most probable mode (MPM) flag and an MPM index for the target decoding unit;
derive neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode;
determine MPM candidates for the target decoding unit using the neighbor prediction mode information;
generate an MPM list using the determined MPM candidates;
derive an intra prediction mode of the target decoding unit using the decoded MPM index and the generated MPM list; and
perform intra prediction on the target decoding unit based on the derived intra prediction mode, and

an adder to add a residual block generated based on the transform coefficients and a prediction block generated by the intra prediction to generate a reconstructed block,
wherein the left neighbor prediction mode is an intra prediction mode of a left neighbor unit adjacent to a left side of the target decoding unit and the upper neighbor prediction mode is an intra prediction mode of an upper neighbor unit adjacent to an upper side of the target decoding unit, and the MPM index is an index indicating the same candidate as the intra prediction mode of the target decoding unit, among the MPM candidates included in the MPM list,
wherein the neighbor prediction mode information includes a mode number of the left neighbor prediction mode and a mode number of the upper neighbor prediction mode,
wherein the prediction module determines the left neighbor prediction mode and the upper neighbor prediction mode as the MPM candidates, and the MPM list comprises three MPM candidates, and
wherein the prediction module determines a predetermined intra prediction mode as an additional MPM candidate when the left neighbor prediction mode is the same as the upper neighbor prediction mode.

2. The video decoding apparatus of claim 1 , wherein the predetermined intra prediction mode is a DC mode or planar mode.

3. The video decoding apparatus of claim 2 , wherein the predetermined intra prediction mode is a DC mode when the left neighbor prediction mode and the upper neighbor prediction mode are a planar mode, and the predetermined intra prediction mode is a planar mode when the left neighbor prediction mode and the upper neighbor prediction mode are a DC mode.

4. A video encoding apparatus comprising:
a prediction module to
determine an intra prediction mode of a target encoding unit;
perform intra prediction on the target encoding unit based on the determined intra prediction mode;
derive neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode;
determine MPM candidates for the target encoding unit using the neighbor prediction mode information;
generate an MPM list using the determined MPM candidates;
derive an MPM index using the intra prediction mode of the target encoding unit and the generated MPM list; and
encode a most probable mode (MPM) flag and the MPM index for the target encoding unit;

a subtractor to generate a residual block using the prediction block generated by the intra prediction and the target encoding unit;
a quantization module to perform quantization on transform coefficients related to the residual block to derive quantized transform coefficients; and
an entropy encoding module to perform entropy-encoding on the quantized transform coefficients,
wherein the left neighbor prediction mode is an intra prediction mode of a left neighbor unit adjacent to a left side of the target encoding unit and the upper neighbor prediction mode is an intra prediction mode of an upper neighbor unit adjacent to an upper side of the target encoding unit, and the MPM index is an index indicating the same candidate as the intra prediction mode of the target encoding unit, among the MPM candidates included in the MPM list,
wherein the neighbor prediction mode information includes a mode number of the left neighbor prediction mode and a mode number of the upper neighbor prediction mode,
wherein the prediction module determines the left neighbor prediction mode and the upper neighbor prediction mode as the MPM candidates, and the MPM list comprises three MPM candidates, and
wherein the prediction module determines a predetermined intra prediction mode as an additional MPM candidate when the left neighbor prediction mode is the same as the upper neighbor prediction mode.

5. The video encoding apparatus of claim 4 , wherein the predetermined intra prediction mode is a DC mode or planar mode.

6. The video encoding apparatus of claim 5 , wherein the predetermined intra prediction mode is a DC mode when the left neighbor prediction mode and the upper neighbor prediction mode are a planar mode, and the predetermined intra prediction mode is a planar mode when the left neighbor prediction mode and the upper neighbor prediction mode are a DC mode.

7. A non-transitory computer-readable medium storing a bitstream that is generated by a video encoding apparatus, the apparatus comprising:
a prediction module to
determine an intra prediction mode of a target encoding unit;
perform intra prediction on the target encoding unit based on the determined intra prediction mode;
derive neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode;
determine MPM candidates for the target encoding unit using the neighbor prediction mode information;
generate an MPM list using the determined MPM candidates;
derive an MPM index using the intra prediction mode of the target encoding unit and the generated MPM list; and
encode a most probable mode (MPM) flag and the MPM index for the target encoding unit;

a subtractor to generate a residual block using the prediction block generated by the intra prediction and the target encoding unit;
a quantization module to perform quantization on transform coefficients related to the residual block to derive quantized transform coefficients; and
an entropy encoding module to perform entropy-encoding on the quantized transform coefficients,
wherein the left neighbor prediction mode is an intra prediction mode of a left neighbor unit adjacent to a left side of the target encoding unit and the upper neighbor prediction mode is an intra prediction mode of an upper neighbor unit adjacent to an upper side of the target encoding unit, and the MPM index is an index indicating the same candidate as the intra prediction mode of the target encoding unit, among the MPM candidates included in the MPM list,
wherein the neighbor prediction mode information includes a mode number of the left neighbor prediction mode and a mode number of the upper neighbor prediction mode,
wherein the prediction module determines the left neighbor prediction mode and the upper neighbor prediction mode as the MPM candidates, and the MPM list comprises three MPM candidates, and
wherein the prediction module determines a predetermined intra prediction mode as an additional MPM candidate when the left neighbor prediction mode is the same as the upper neighbor prediction mode.

Assignees

• Electronics & Telecommunications Res Inst

Inventors

• Lee Ha Hyun
• Kim Hui Yong
• Lim Sung Chang
• Kim Jong Ho
• Lee Jin Ho
• Jeong Se Yoon
• Cho Suk Hee
• Choi Jin Soo
• Kim Jin Woong
• Ahn Chie Teuk

Classifications

• H04N19/159

  Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction · CPC title

• H04N19/157

  Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter · CPC title

• H04N19/50

  using predictive coding (H04N19/61 takes precedence) · CPC title

• H04N19/1887

  the unit being a variable length codeword · CPC title

• H04N19/107 Primary

  between spatial and temporal predictive coding, e.g. picture refresh · CPC title