In-loop filtering method and apparatus for same

Patent metadata

Field	Value
Publication number	US-10419764-B2
Application number	US-201214007979-A
Country	US
Kind code	B2
Filing date	Mar 30, 2012
Priority date	Mar 30, 2011
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

According to the present invention, an image-encoding method comprises the following steps: receiving image information; generating a restored block for the current block based on the image information; and generating a finally restored block for the current block by applying an in-loop filter to the restored block on the basis of the image information. According to the present invention, image-encoding/decoding efficiency may be improved.

First claim

The invention claimed is:

1. A video decoding method, by a decoding apparatus, comprising:
receiving video information;
identifying whether an intra pulse code modulation (I_PCM) mode is applied to a current block in a current picture based on the video information;
generating a reconstructed picture including a reconstructed block of the current block based on the video information;
determining whether a deblocking filter is to be applied to the reconstructed block based on the result of the identification;
determining whether sample adaptive offset (SAO) is to be applied to the reconstructed block based on the result of the identification; and
generating a modified reconstructed picture based on the reconstructed picture and the results of the determinations,
wherein when the I_PCM mode is applied to the current block, the deblocking filter is not applied to the reconstructed block,
wherein when the I_PCM mode is applied to the current block, the SAO is not applied to the reconstructed block,
wherein a coding block in the current picture is split into multiple coding units (CUs) based on a quad-tree structure,
wherein a prediction unit (PU) is partitioned from a CU which is one of the multiple CUs, and an intra prediction mode or an inter prediction mode is determined at a PU level,
wherein the current block corresponds to a first CU,
wherein for a second CU to which the I_PCM mode is not applied, a first PU and a second PU are derived from the second CU,
wherein motion information of the first PU is determined differently from motion information of the second PU,
wherein the modified reconstructed picture is generated based on the deblocking filter and the SAO on the reconstructed picture,
wherein a first clipping is applied to a first output of the deblocking filter,
wherein a second clipping is applied to a second output of the SAO, and
wherein the clipped first output is used as an input of the SAO.

2. The video decoding method of claim 1 , wherein the deblocking filter comprises determining a boundary strength (bS) of a block edge located within or on a boundary of the reconstructed block and determining whether to apply a deblocking filter to the block edge based on the bS, and
wherein a pixel value which is not subjected to the deblocking filter within the reconstructed block is determined as the final pixel value when it is determined that the deblocking filter is not applied to the reconstructed block.

3. The video decoding method of claim 2 , wherein the deblocking filter is not applied to the block edge when it is determined that deblocking filter is not applied to the reconstructed block.

4. The video decoding method of claim 1 , wherein the SAO comprise determining whether a band offset type is to be applied, deriving a band group including multiple bands among 32 band, applying an offset corresponding a band in the band group to a value of a pixel in the reconstructed block,
wherein the value of the pixel in the reconstructed block is determined as final pixel value when it is determined that the SAO is not applied to the reconstructed block.

5. The video decoding method of claim 1 , further comprising determining whether an adaptive loop filter (ALF) is applied to the reconstructed block based on the result of the identification,
wherein the ALF comprises determining a filter shape and a filter coefficient for the ALF, and deriving the final pixel value based on the filter shape and the filter coefficient, and
wherein a pixel value which is not subjected to the ALF within the reconstructed block is determined as the final pixel value when it is determined that the ALF is not applied to the reconstructed block.

6. The video decoding method of claim 1 , wherein the video information further comprises PCM flag information to instruct whether the current block is coded in the I_PCM mode.

7. The video decoding method of claim 6 , wherein the video information further comprises PCM loop filter flag information to instruct whether an in-loop filter is disabled to a block coded in the I_PCM mode, and
wherein both the deblocking filter and the SAO are not applied to the reconstructed block when the PCM loop filter flag information has value 1 and the PCM flag information has value 1.

8. The video decoding method of claim 6 , wherein the video information further comprises ALF flag information to instruct whether adaptive loop filtering (ALF) is performed on the current block; and the determining of whether to apply the ALF determines whether to apply the ALF based on the PCM flag information and the ALF flag information.

9. The video decoding method of claim 1 , wherein the generating the reconstructed picture includes:
performing inter prediction on the first PU based on the motion information of the first PU;
performing inter prediction on the second PU based on the motion information of the second PU; and
generating a reconstructed block of the second CU based on the result of the inter prediction on the first PU and the result of the inter prediction on the second PU.

Assignees

• Park Seung Wook
• Lim Jae Hyun
• Kim Jung Sun
• Park Joon Young
• Choi Young Hee
• Jeon Byeong Moon
• Jeon Yong Joon
• Lg Electronics Inc

Inventors

• Park Seung Wook
• Lim Jae Hyun
• Kim Jung Sun
• Park Joon Young
• Choi Young Hee
• Jeon Byeong Moon
• Jeon Yong Joon

Classifications

• H04N19/80

  Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation (H04N19/635, H04N19/86 take precedence) · CPC title

• H04N19/117

  Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) · CPC title

• H04N19/176 Primary

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

• H04N19/182

  the unit being a pixel · CPC title

• H04N19/157 Primary

  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