Method and apparatus for encoding and decoding video signal

Patent metadata

Field	Value
Publication number	US-10587873-B2
Application number	US-201615768326-A
Country	US
Kind code	B2
Filing date	Oct 13, 2016
Priority date	Oct 13, 2015
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

The present invention provides a method for processing a video signal, comprising generating a prediction block for a neighbor block using a reconstructed reference pixel of the neighbor block when the neighbor block adjacent to a current block is intra-coded; determining a refined intra prediction mode of the neighbor block based on the prediction block, where the refined intra prediction mode represents a mode which minimizes an error between the prediction block and a reconstructed neighbor block; generating a prediction mode candidate list for the current block based on the refined intra prediction mode; selecting an intra prediction mode for the current block from the prediction mode candidate list; and performing a prediction for the current block based on the intra prediction mode.

First claim

The invention claimed is:

1. A method for processing a video signal, comprising:
generating, based on a neighbor block adjacent to a current block being intra-coded with a first prediction block, a second prediction block for the neighbor block using a reconstructed reference pixel of the neighbor block,
wherein a shape or a size of the first prediction block is different from a shape or a size of the current block, and
wherein a shape or a size of the second prediction block is the same as the shape or size of the current block;
determining a refined intra prediction mode of the neighbor block based on the prediction block, wherein the refined intra prediction mode represents a mode which minimizes an error between the second prediction block and a reconstructed neighbor block;
generating a prediction mode candidate list for the current block based on the refined intra prediction mode;
selecting an intra prediction mode for the current block from the prediction mode candidate list; and
performing a prediction for the current block based on the intra prediction mode.

2. The method of claim 1 , wherein a prediction mode for the neighbor block is generated for the entire intra prediction modes, and
wherein the refined intra prediction mode is a mode which minimizes an error from the reconstructed neighbor block based on prediction blocks generated for the entire intra prediction modes.

3. The method of claim 1 , wherein a prediction mode for the neighbor block is generated for a specific intra prediction mode, and the specific intra prediction mode represents an intra prediction mode within a predetermined range from an intra prediction mode of the neighbor block; and
the refined intra prediction mode is a mode which minimizes an error from the reconstructed neighbor block on the basis of prediction blocks generated for the specific intra prediction mode.

4. The method of claim 1 , further comprising determining, based on an intra prediction mode of the neighbor block being an intra planar mode or an intra DC mode, the refined intra prediction mode as an intra prediction mode of the neighbor block.

5. The method of claim 1 , wherein the neighbor block comprises at least one of a left neighbor block or an upper neighbor block of the current block, and
wherein the reconstructed reference pixel of the neighbor block comprises at least one of a left boundary pixel, an upper-left corner pixel, or an upper boundary pixel adjacent to the neighbor block.

6. The method of claim 5 , further comprising determining, based on an intra prediction mode of the left neighbor block being the same as an intra prediction mode of the upper neighbor block, the refined intra prediction mode as an intra prediction mode of the neighbor block.

7. The method of claim 1 , further comprising
obtaining a mode index from the video signal,
wherein the mode index represents an index indicating a prediction mode of the current block, and
wherein an intra prediction mode for the current block is selected based on the mode index.

8. An apparatus for processing a video signal, comprising:
a storage device configured to store the video signal; and
a processor coupled to the storage device, and configured to:
generate, based on a neighbor block adjacent to a current block being intra-coded with a first prediction block, a second prediction block for the neighbor block using a reconstructed reference pixel of the neighbor block;
determine a refined intra prediction mode of the neighbor block based on the second prediction block;
generate a prediction mode candidate list for the current block based on the refined intra prediction mode;
select an intra prediction mode for the current block from the prediction mode candidate list;
perform a prediction for the current block based on the intra prediction mode; and
reconstruct the video signal based on the prediction result,
wherein a shape or a size of the first prediction block is different from a shape or a size of the current block,
wherein a shape or a size of the second prediction block is the same as the shape or size of the current block, and
wherein the refined intra prediction mode is a mode which minimizes an error between the second prediction block and the reconstructed neighbor block.

9. The apparatus of claim 8 , wherein a prediction mode for the neighbor block is generated for the entire intra prediction modes, and
wherein the refined intra prediction mode is a mode which minimizes an error from the reconstructed neighbor block based on prediction blocks generated for the entire intra prediction modes.

10. The apparatus of claim 8 , wherein a prediction mode for the neighbor block is generated for a specific intra prediction mode, and the specific intra prediction mode represents an intra prediction mode within a predetermined range from an intra prediction mode of the neighbor block, and
wherein the refined intra prediction mode is a mode which minimizes an error from the reconstructed neighbor block on the basis of prediction blocks generated for the specific intra prediction mode.

11. The apparatus of claim 8 , wherein the neighbor block comprises at least one of a left neighbor block or an upper neighbor block of the current block, and
wherein the reconstructed reference pixel of the neighbor block comprises at least one of a left boundary pixel, an upper-left corner pixel, or upper boundary pixel adjacent to the neighbor block.

12. The apparatus of claim 8 , wherein the processor is further configured to:
obtain a mode index from the video signal,
wherein the mode index represents an index indicating the prediction mode of the current block, and
wherein an intra prediction mode for the current block is selected based on the mode index.

Assignees

• Lg Electronics Inc

Inventors

• Koo Moonmo
• Yea Sehoon
• Kim Kyuwoon
• Lee Bumshik

Classifications

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/147

  according to rate distortion criteria (rate-distortion as a criterion for motion estimation H04N19/567) · CPC title

• H04N19/159

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

• H04N19/11 Primary

  among a plurality of spatial predictive coding modes · CPC title

• H04N19/105 Primary

  Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction · CPC title