Methods and devices for filtered intra block copy

Patent metadata

Field	Value
Publication number	US-2026089340-A1
Application number	US-202519408683-A
Country	US
Kind code	A1
Filing date	Dec 4, 2025
Priority date	Jun 8, 2023
Publication date	Mar 26, 2026
Grant date	—

Abstract

A method for video decoding, comprising: determining an initial prediction block of a current block to be predicted based on a first block vector, wherein the first block vector is a fractional block vector between the current block and a reference block; determining a reference template based on a current template associated with the current block and a second block vector; obtaining a set of filter coefficients corresponding to a filter shape based at least on sample values from both the current template and the reference template; and deriving, by applying the set of filter coefficients and the filter shape to the initial prediction block, a final prediction block of the current block comprising predicted sample values of the current block.

First claim

What is claimed is:

1 . A method for video decoding, comprising:
determining an initial prediction block of a current block to be predicted based on a first block vector, wherein the first block vector is a fractional block vector between the current block and a reference block; determining a reference template based on a current template associated with the current block and a second block vector; obtaining a set of filter coefficients corresponding to a filter shape based at least on sample values from both the current template and the reference template; and deriving, by applying the set of filter coefficients and the filter shape to the initial prediction block, a final prediction block of the current block comprising predicted sample values of the current block.

2 . The method of claim 1 , wherein determining the initial prediction block further comprises:
determining the reference block based on the first block vector and the current block; and determining the initial prediction block by deriving interpolated sample values of the reference block based on a first interpolation filter.

3 . The method of claim 1 , wherein the second block vector is an integer block vector modified from the first block vector based on a clipping operation or a rounding operation.

4 . The method of claim 1 , wherein the second block vector is the same as the first block vector.

5 . The method of claim 4 , wherein determining the reference template further comprises:
deriving interpolated sample values of the reference template based on a second interpolation filter.

6 . The method of claim 5 , wherein the second interpolation filter is different from a first interpolation filter for determining the initial prediction block.

7 . The method of claim 6 , wherein the second interpolation filter has fewer taps than the first interpolation filter.

8 . The method of claim 6 , wherein the second interpolation filter is predefined or obtained at different coding levels.

9 . The method of claim 1 , further comprising:
in response to determining that the first block vector is a fractional block vector, obtaining the final prediction block by using intra block copy (IBC) mode.

10 . A method for video encoding, comprising:
determining an initial prediction block of a current block to be predicted based on a first block vector, wherein the first block vector is a fractional block vector between the current block and a reference block; determining a reference template based on a current template associated with the current block and a second block vector; obtaining a set of filter coefficients corresponding to a filter shape based at least on sample values from both the current template and the reference template; deriving, by applying the set of filter coefficients and the filter shape to the initial prediction block, a final prediction block of the current block comprising predicted sample values of the current block; and generating a bitstream based on the final prediction block.

11 . The method of claim 10 , wherein determining the initial prediction block further comprises:
determining the reference block based on the first block vector and the current block; and determining the initial prediction block by deriving interpolated sample values of the reference block based on a first interpolation filter.

12 . The method of claim 10 , wherein the second block vector is an integer block vector modified from the first block vector based on a clipping operation or a rounding operation.

13 . The method of claim 10 , wherein the second block vector is the same as the first block vector.

14 . The method of claim 13 , wherein determining the reference template further comprises:
deriving interpolated sample values of the reference template based on a second interpolation filter.

15 . The method of claim 14 , wherein the second interpolation filter is different from a first interpolation filter for determining the initial prediction block.

16 . The method of claim 15 , wherein the second interpolation filter has fewer taps than the first interpolation filter.

17 . The method of claim 15 , wherein the second interpolation filter is signaled at different coding levels.

18 . The method of claim 10 , further comprising:
in response to determining that the first block vector is a fractional block vector, obtaining the final prediction block by using intra block copy (IBC) mode.

19 . An electronic apparatus, comprising:
one or more processors; and one or more memories storing computer-executable instructions that, when executed by the one or more processors, cause the electronic apparatus to perform decoding operations including the one or more processors configured to:
determine an initial prediction block of a current block to be predicted based on a first block vector, wherein the first block vector is a fractional block vector between the current block and a reference block;
determine a reference template based on a current template associated with the current block and a second block vector;
obtain a set of filter coefficients corresponding to a filter shape based at least on sample values from both the current template and the reference template; and
derive, by applying the set of filter coefficients and the filter shape to the initial prediction block, a final prediction block of the current block comprising predicted sample values of the current block.

20 . A non-transitory computer readable storage medium storing a bitstream to be decoded by the decoding method according to claim 1 .

Assignees

• Beijing Dajia Internet Information Tech Co Ltd

Inventors

• Jhu Hong-Jheng
• Kuo Che-Wei
• Xiu Xiaoyu
• Yan Ning
• Chen Wei
• Ma Changyue
• Wang Xianglin
• Yu Bing

Classifications

• H04N19/117

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

• H04N19/159

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

• H04N19/80

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

• H04N19/105

  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

• H04N19/176 Primary

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