	US 11,871,034 B2
	Intra block copy for screen content coding
Xiaoyu Xiu, San Diego, CA (US); Yi-Wen Chen, San Diego, CA (US); Xianglin Wang, San Diego, CA (US); and Tsung-Chuan Ma, San Diego, CA (US)
Assigned to Beijing Dajia Internet Information Technology Co., Ltd., Beijing (CN)
Appl. No. 17/438,375
Filed by BEIJING DAJIA INTERNET INFORMATION TECHNOLOGY CO., LTD., Beijing (CN); and Xiaoyu Xiu, San Diego, CA (US)
PCT Filed Mar. 11, 2020, PCT No. PCT/US2020/022187 § 371(c)(1), (2) Date Sep. 10, 2021, PCT Pub. No. WO2020/185964, PCT Pub. Date Sep. 17, 2020.
Claims priority of provisional application 62/816,902, filed on Mar. 11, 2019.
Prior Publication US 2022/0159295 A1, May 19, 2022
Int. Cl. H04N 19/593 (2014.01); H04N 19/147 (2014.01); H04N 19/154 (2014.01); H04N 19/176 (2014.01)

CPC H04N 19/593 (2014.11) [H04N 19/147 (2014.11); H04N 19/154 (2014.11); H04N 19/176 (2014.11)]

17 Claims

1. A video coding method, comprising:

receiving a video picture comprising a plurality of coding units, wherein each coding unit of the plurality of coding units is predicted from a reference coding unit in the same picture by an intra block copy (IBC) mode, the reference coding unit is a reconstructed coding unit, and the plurality of coding units comprise a first coding unit;

dividing the picture into multiple non-overlapped blocks and calculating, by an encoder, a hash value of each block of the multiple non-overlapped blocks;

classifying all the non-overlapped blocks into at least two categories comprising a first category and a second category, wherein the first category comprises one or more blocks representing one or more hash values covered by a first set of hash values, and the second category comprises all remaining blocks;

classifying the blocks in the second category into at least two groups including a first group, wherein the first group comprises one or more blocks representing the same hash value as another block in the second category;

determining a distortion metric for calculating the differences between samples in one coding unit and samples of its reference coding unit in the same picture; and

obtaining, based on the distortion metric, an optimal block vector (BV) of a first coding unit in the picture, wherein a BV of the first coding unit is a displacement between the first coding unit and its reference coding unit in the same picture,

wherein determining the distortion metric comprises at least one of followings:

using sum absolute difference (SAD) as the distortion metric in response to determining that the percentage of the blocks in the first group of the second category is greater than one predetermined threshold; and

using sum absolute transformed difference (SATD) as the distortion metric in response to determining that the percentage of the blocks in the first group of the second category is not greater than the predetermined threshold.