US-12621463-B2 - Method and apparatus for processing a video signal

US12621463B2US 12621463 B2US12621463 B2US 12621463B2US-12621463-B2

Abstract

The present invention discloses a method and apparatus for encoding or decoding a video signal. The method for processing a video signal according to the present invention uses a merging mode in which prediction information on a neighbor unit is used instead of transmitting prediction information on the present unit, so as to improve coding efficiency. In this case, the number of available candidate units for merging among the units in a predetermined position is determined, and information for the merging mode is acquired on the basis of the number of the available candidate units for merging. The unit to be merged is determined using the information for the merging mode, and prediction information on the unit to be merged is acquired. The prediction value for the present unit is acquired using the prediction information on the unit to be merged, and the present unit is restored using the acquired prediction value.

Inventors

Seungwook Park
Joonyoung Park
Jungsun KIM
Younghee CHOI
Yongjoon Jeon
Jaewon SUNG
Byeongmoon Jeon
Jaehyun Lim

Assignees

LG ELECTRONICS INC.

Dates

Publication Date: 20260505
Application Date: 20240709

Claims (16)

1 . A method for decoding a bitstream for a video signal comprising at least one coding block by a decoding apparatus, the method comprising: obtaining a plurality of prediction blocks being partitioned from the coding block; obtaining, by the decoding apparatus, merge flag information indicating whether prediction information of a current prediction block among the plurality of prediction blocks is determined by prediction information of a merging candidate selected from merging candidates, the merging candidates comprise at least one neighboring prediction block adjacent to the current prediction block; and based on the merge flag information indicating that the prediction information of the current prediction block is determined by the prediction information of the selected merging candidate, decoding, by the decoding apparatus, the current prediction block based on the prediction information of the selected merging candidate, wherein, based on the coding block being partitioned into two rectangular prediction blocks having a width longer than a height and having the height different from each other and the current prediction block being a bottom prediction block among the two rectangular prediction blocks having the width longer than the height and having the height different from each other, a top prediction block among the two rectangular prediction blocks having a width longer than a height and having the height different from each other is excluded from the merging candidates, and wherein, based on the coding block being partitioned into two rectangular prediction blocks having the height longer than the width and having the width different from each other and the current prediction block being a right prediction block among the two rectangular prediction blocks having the height longer than the width and having the width different from each other, a left prediction block of the two rectangular prediction blocks having the height longer than the width and having the width different from each other is excluded from the merging candidates.
2 . The method of claim 1 , wherein each of the prediction information comprises reference index information and motion vector information of a corresponding prediction block.
3 . The method of claim 1 , wherein the current prediction block is coded in an inter-prediction mode.
4 . The method of claim 1 , wherein each of the at least one neighboring prediction block is coded in an inter-prediction mode.
5 . The method of claim 1 , wherein the at least one neighboring prediction block includes at least one of a left neighboring prediction block, a top-left neighboring prediction block, a top-right neighboring prediction block, or a bottom-left neighboring prediction block.
6 . The method of claim 1 , further comprising: obtaining, by the decoding apparatus, merge index information from the bitstream, wherein the merge index information indicates the selected merging candidate from among the merging candidates.
7 . The method of claim 1 , wherein the merging candidates include up to five neighboring prediction blocks adjacent to the current prediction block.
8 . A decoding apparatus for decoding a bitstream for a video signal comprising at least one coding block, the decoding apparatus comprising: a processor configured to: obtain a plurality of prediction blocks being partitioned from the coding block, obtain merge flag information indicating whether prediction information of a current prediction block among the plurality of prediction blocks is determined by prediction information of a merging candidate selected from merging candidates, the merging candidates comprise at least one neighboring prediction block adjacent to the current prediction block, and based on the merge flag information indicating that the prediction information of the current prediction block is determined by the prediction information of the selected merging candidate, decode the current prediction block based on the prediction information of the selected merging candidate, wherein, based on the coding block being partitioned into two rectangular prediction blocks having a width longer than a height and having the height different from each other and the current prediction block being a bottom prediction block among the two rectangular prediction blocks having the width longer than the height and having the height different from each other, a top prediction block among the two rectangular prediction blocks having a width longer than a height and having the height different from each other is excluded from the merging candidates, and wherein, based on the coding block being partitioned into two rectangular prediction blocks having the height longer than the width and having the width different from each other and the current prediction block being a right prediction block among the two rectangular prediction blocks having the height longer than the width and having the width different from each other, a left prediction block of the two rectangular prediction blocks having the height longer than the width and having the width different from each other is excluded from the merging candidates.
9 . The decoding apparatus of claim 8 , wherein each of the prediction information comprises reference index information and motion vector information of a corresponding prediction block.
10 . The decoding apparatus of claim 8 , wherein the current prediction block is coded in an inter-prediction mode.
11 . The decoding apparatus of claim 8 , wherein each of the at least one neighboring prediction block is coded in an inter-prediction mode.
12 . The decoding apparatus of claim 8 , wherein the at least one neighboring prediction block includes at least one of a left neighboring prediction block, a top-left neighboring prediction block, a top-right neighboring prediction block, or a bottom-left neighboring prediction block.
13 . The decoding apparatus of claim 8 , wherein the entropy decoding unit is further configured to obtain merge index information from the bitstream, wherein the merge index information indicates the selected merging candidate from among the merging candidates.
14 . The decoding apparatus of claim 8 , wherein the merging candidates include up to five neighboring prediction blocks adjacent to the current prediction block.
15 . A method for encoding a bitstream for a video signal comprising at least one coding block to be partitioned into a plurality of prediction blocks by an encoding apparatus, the method comprising: encoding into the bitstream, by the encoding apparatus, merge flag information indicating whether prediction information of a current prediction block among the plurality of prediction blocks is determined by prediction information of a merging candidate selected from merging candidates, the merging candidates comprise at least one neighboring prediction block adjacent to the current prediction block; and based on the merge flag information indicating that prediction information of the current prediction block is determined by prediction information of the selected merging candidate, encoding, by the encoding apparatus, the current prediction block based on the prediction information of the selected merging candidate, wherein, based on the coding block being partitioned into two rectangular prediction blocks having a width longer than a height and having the height different from each other and the current prediction block being a bottom prediction block among the two rectangular prediction blocks having the width longer than the height and having the height different from each other, a top prediction block among the two rectangular prediction blocks having a width longer than a height and having the height different from each other is excluded from the merging candidates, and wherein, based on the coding block being partitioned into two rectangular prediction blocks having the height longer than the width and having the width different from each other and the current prediction block being a right prediction block among the two rectangular prediction blocks having the height longer than the width and having the width different from each other, a left prediction block of the two rectangular prediction blocks having the height longer than the width and having the width different from each other is excluded from the merging candidates.
16 . An encoding apparatus for encoding a bitstream for a video signal comprising at least one coding block to be partitioned into a plurality of prediction blocks, the encoding apparatus comprising: a processor configured to: encode merge flag information indicating whether prediction information of a current prediction block among the plurality of prediction blocks is determined by prediction information of a merging candidate selected from merging candidates, the merging candidates comprise at least one neighboring prediction block adjacent to the current prediction block; and based on the merge flag information indicating that prediction information of the current prediction block is determined by prediction information of the selected merging candidate, encode the current prediction block based on the prediction information of the selected merging candidate, wherein, based on the coding block being partitioned into two rectangular prediction blocks having a width longer than a height and having the height different from each other and the current prediction block being a bottom prediction block among the two rectangular prediction blocks having the width longer than the height and having the height different from each other, a top prediction block among the two rectangular prediction blocks having a width longer than a height and having the height different from each other is excluded from the merging candidates, and wherein, based on the coding block being partitioned into two rectangular prediction blocks having the height longer than the width and having the width different from each other and the current prediction block being a right prediction block among the two rectangular prediction blocks having the height longer than the width and having the width different from each other, a left prediction block of the two rectangular prediction blocks having the height longer than the width and having the width different from each other is excluded from the merging candidates.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 18/089,253, filed on Dec. 27, 2022, which is a continuation of U.S. application Ser. No. 17/240,282, filed on Apr. 26, 2021, now U.S. Pat. No. 11,553,185, which is a continuation of U.S. application Ser. No. 16/849,646, filed on Apr. 15, 2020, now U.S. Pat. No. 11,006,123, which is a continuation of U.S. application Ser. No. 16/225,858, filed on Dec. 19, 2018, now U.S. Pat. No. 10,666,947, which is a continuation of U.S. application Ser. No. 15/942,897, filed Apr. 2, 2018, now U.S. Pat. No. 10,397,580, which is a continuation of U.S. application Ser. No. 15/143,719, filed May 2, 2016, now U.S. Pat. No. 9,936,202, which is a continuation of U.S. application Ser. No. 14/624,739, filed Feb. 18, 2015, now U.S. Pat. No. 9,357,218, which is a continuation of U.S. application Ser. No. 13/695,838, filed Jan. 16, 2013, now U.S. Pat. No. 9,363,520, which is a U.S. National Phase Application under 35 U.S.C. § 371 of International Application PCT/KR2011/003350, filed on May 4, 2011, which claims the benefit of U.S. Provisional Application No. 61/330,902, filed on May 4, 2010, U.S. Provisional Application No. 61/333,273, filed on May 11, 2010, U.S. Provisional Application No. 61/412,801, filed on Nov. 12, 2010 and U.S. Provisional Application No. 61/414,436, filed on Nov. 17, 2010, the entire contents of which are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present invention relates to a method and apparatus for processing a video signal, and more particularly, to a method and apparatus for encoding or decoding a video signal. BACKGROUND ART Compression encoding refers to a signal processing technology for transmitting digitized information through a communication line or storing such information in a form which is appropriate for a storage medium. Voices, images, letters, etc. may be compression-encoded, and particularly a technology for performing compression encoding of images is called video image compression. Compression encoding of a video signal may be performed by removing surplus information in consideration of spatial correlation, temporal correlation, probabilistic correlation, etc. However, with recent development of various media and data transmission media, there is a need for a high efficiency video signal processing method and apparatus. SUMMARY An object of the present invention devised to solve the problem lies in reducing transmitted prediction information by restoring a current unit through a merging mode which uses prediction information of another already restored unit in inter prediction of the current unit. Another object of the present invention devised to solve the problem lies in efficiently implementing a prediction mode and more accurately predicting prediction information of a current block. Yet another object of the present invention devised to solve the problem lies in selecting appropriate merging candidate units and efficiently determining a unit to be merged in consideration of characteristics of the current unit and merged neighbor areas. Yet another object of the present invention devised to solve the problem lies in providing a method for enhancing efficiency in a signaling method for implementing a prediction mode. The present invention has been designed to solve the above problems, and the method for processing a video signal according to the present invention uses a structure for recursively partitioning one coding unit into several coding units and a method thereof. Further, such a coding unit is divided into various forms of prediction units, and thereby the accuracy of motion prediction compensation may be enhanced. The present invention may use a merging mode for increasing coding efficiency. Here, a method of selecting merging candidate units in various positions is presented. The present invention presents an efficient signaling method for specifying a unit to be merged among merging candidate units. Further, the present invention presents a method for inducing a unit to be merged without transmitting the information. To this end, a method of adaptively determining a unit to be merged may be used in consideration of various conditions such as the position of a current unit and neighbor units, unit size, motion information, etc. According to a method for processing a video signal according to the present invention, complexity, which is needed for acquiring motion information of a current unit, may be reduced by the merger between units in performing inter prediction, and coding efficiency may be enhanced by not transmitting prediction information of the current unit. Further, characteristics of images or objects within the images may be well reflected by the prediction and merger in various unit sizes and partition units, and more accurate prediction is possible. Further, flexibility of merger may be extended by selecting neighbor units of var