ENCODER, DECODER, COMPUTER PROGRAM AND COMPUTER PROGRAM PRODUCT FOR PROCESSING A FRAME OF A VIDEO SEQUENCE

• US 20200137386A1
• Filed: 12/30/2019
• Published: 04/30/2020
• Est. Priority Date: 06/30/2017
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: ZHAO, Zhijie, BLAESER, Max, WIEN, Mathias
• Granted Patent: US 11,039,137 B2
• Time in Patent Office: Days
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/56 Motion estimation with initialisation of the vector search, e.g. estimating a good candidate to initiate a search
• CPC Class Codes: H04N 19/567 Motion estimation based on rate distortion criteria
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

The present invention provides an encoder for encoding a frame of a video sequence and a corresponding decoder. The encoder comprises a partitioner and an entropy coder. The partitioner is configured to receive a current block of the frame and obtain a list of candidate geometric partitioning (GP) lines. Each of the candidate GP lines is generated based on information of one or more candidate neighbor blocks of the current block. The partitioner is further configured to determine a final GP line that partitions the current block into two segments, select a GP line from the list of GP lines to obtain a selected GP line, and generate a GP parameter for the current block. The GP parameter includes offset information indicating an offset between the final GP line and the selected GP line. The entropy coder is configured to encode the GP parameter.

Claims

1. An encoder for encoding a frame of a video sequence, comprising:

a partitioner; and

an entropy coder,

wherein the partitioner is configured to;

receive a current block of the frame;

obtain a list of one or more candidate geometric partitioning (GP) lines, wherein each of the one or more candidate GP lines is generated based on information of one or more candidate neighbor blocks of the current block;

determine a final GP line that partitions the current block into two segments;

select a GP line from the list of the one or more candidate GP lines to obtain a selected GP line; and

generate a GP parameter for the current block, wherein the GP parameter includes offset information indicating an offset between the final GP line and the selected GP line,

wherein the entropy coder is configured to encode the GP parameter.

2. The encoder according to claim 1, wherein the list comprises, for each respective candidate GP line of the one or more candidate GP lines, respective candidate GP line specific line information,

wherein the respective candidate GP line specific line information comprises a coordinate (x,y) indicating a start point and a coordinate indicating an end point of the respective candidate GP line, or

wherein the respective candidate GP line specific line information comprises a distance between the respective candidate GP line and a center of the current block, and an angle of the respective candidate GP line.

3. The encoder according to claim 2, wherein the offset between the final GP line and the selected GP line comprises an offset between the start point of the selected GP line and a start point of the final GP line, and an offset between the end point of the selected GP line and an end point of the final GP line.

4. The encoder according to claim 1, wherein the one or more candidate neighbor blocks includes a first candidate neighbor block,

wherein the information of the one or more candidate neighbor blocks includes information of the first candidate neighbor block,

wherein the one or more candidate GP lines includes a first candidate GP line, and wherein:

the information of the first candidate neighbor block comprises information of a neighbor GP line partitioning the first candidate neighbor block and the first candidate GP line is generated by extending the neighbor GP line into the current block; and

/or

the information of the first candidate neighbor block comprises information of a neighbor horizontal or vertical line partitioning the first candidate neighbor block into two rectangular segments and the first candidate GP line is generated by extending the neighbor horizontal or vertical line into the current block; and

/or

the information of the first candidate neighbor block comprises an intra prediction mode of the first candidate neighbor block and the first candidate GP line is generated by analysis of the intra prediction mode; and

/or

the information of the first candidate neighbor block comprises texture components or motion vector field of the first candidate neighbor block and the first candidate GP line is generated by performing segmentation of the first candidate neighbor block using the texture components or the motion vector field to obtain a neighbor GP line partitioning the first candidate neighbor block and extending the neighbor GP line into the current block.

5. The encoder according to claim 1, wherein the list comprises two or more candidate GP lines, and

wherein the partitioner is further configured to select, as the selected GP line, the candidate GP line from the list that is closest to the final GP line or the partitioner is further configured to select the selected GP line such that a rate distortion is minimized.

6. The encoder according to claim 1, wherein the GP parameter further includes information of the selected GP line.

7. The encoder according to claim 6, wherein:

the information of the selected GP line includes a block index of a selected neighbor block corresponding to the selected GP line;

or

the list comprises two or more candidate GP lines and a line index for each of the candidate GP lines, and the information of the selected GP line includes a line index of the selected GP line.

8. The encoder according to any of claim 1, wherein the one or more candidate neighbor block blocks includes one default neighbor block of the current block.

9. The encoder according to claim 1, wherein the partitioning unit is configured to determine the final GP line by:

selecting a candidate GP line from the list as an initial GP line; and

one or more of;

repeatedly modifying the selected intial GP line to obtain a modified GP line, calculating a rate distortion cost for the modified GP line, and selecting the modified GP line as the final GP line if the rate distortion cost of the modified GP line is below or equal to a threshold, and

repeatedly modifying the selected intial GP line to obtain a plurality of modified GP lines, calculating a rate distortion cost for each of the plurality of modified GP lines, and selecting the modified GP line with the smallest rate distortion cost.

10. The encoder according to claim 1, wherein the offset information comprises a step size and a quantized offset value, wherein an offset between the final GP line and the selected GP line corresponds to a product of the step size and the quantized offset value.

22. A computer program with program code means for performing all steps according to claim 1 if the program is executed on a computer or a digital signal processor.

23. A computer program product having a computer readable medium with stored program code means for performing all steps according to claim 1 if the program is executed on a computer or a digital signal processor.

11. A decoder for decoding a frame in a video sequence, comprising:

an entropy decoder, and

a partitioner,

wherein the entropy decoder is configured to decode an encoded geometric partitioning (GP) parameter for a current block, wherein the encoded GP parameter includes offset information indicating an offset between a final GP line and a selected GP line, and

wherein the partitioner is configured to;

generate a list of one or more candidate GP lines, wherein each of the one or more candidate GP lines is generated based on information of each of one or more candidate neighbor blocks of the current block;

select a GP line from the list of the one or more candidate GP lines to obtain the selected GP line; and

obtain, based on the decoded GP parameter and the selected GP line, the final GP line,

wherein the final GP line partitions the current block into two segments, and

wherein the GP parameter includes offset information indicating an offset between the final GP line and the selected GP line.

12. The decoder according to claim 11, wherein the list comprises, for each respective candidate GP line of the one or more candidate GP lines, respective candidate GP line specific line information,

wherein the respective candidate GP line specific line information comprises a coordinate (x,y) indicating a start point and a coordinate indicating an end point of the respective candidate GP line;

or

wherein the respective candidate GP line specific line information comprises a distance between the respective candidate GP line and a center of the current block, and an angle of the respective candidate GP line.

13. The decoder according to claim 12, wherein the offset between the final GP line and the selected GP line comprises an offset between the start point of the selected GP line and a start point of the final GP line, and an offset between the end point of the selected GP line and an end point of the final GP line.

14. The decoder according to claim 11, wherein the one or more candidate neighbor blocks includes a first candidate neighbor block,

wherein the information of the one or more candidate neighbor blocks includes information of the first candidate neighbor block,

wherein the one or more candidate GP lines includes a first candidate GP line, and

wherein:

the information of the first candidate neighbor block comprises information of a neighbor GP line partitioning the first candidate neighbor block, and the first candidate GP line is generated by extending the first neighbor GP line into the current block; and

/or

the information of the first candidate neighbor block comprises information of a neighbor horizontal or vertical line partitioning the first candidate neighbor block into two rectangular segments, and the first candidate GP line is generated by extending the neighbor horizontal or vertical line into the current block; and

/or

the information of the first candidate neighbor block comprises intra prediction mode of the first candidate neighbor block, and the first candidate GP line is generated based on analysis of the intra prediction mode; and

/or

the information of the first candidate neighbor block comprises texture components or motion vector field of the first candidate neighbor block, and the first candidate GP line is generated by;

performing segmentation of the neighbor block using the texture components or the motion vector field to obtain a neighbor GP line partitioning the first candidate neighbor block; and

extending the neighbor GP line into the current block.

15. The decoder according to claim 11, wherein the encoded GP parameter further includes information of the selected GP line.

16. The decoder according to any of claims 15, wherein the information of the selected GP line is a line index of the selected GP line;

wherein the list includes a line index for each of the one or more candidate GP lines,

wherein the one or more candidate neighbor blocks is each of multiple neighbor blocks of the current block; and

wherein the partitioner is further configured to obtain the selected GP line by selecting a candidate GP line from the list according to the line index of the selected GP line.

17. The decoder according to claim 15, wherein the information of the selected GP line is a block index of a selected neighbor block corresponding to the selected GP line;

wherein the one or more candidate neighbor blocks of the current block include the selected neighbor block; and

wherein the partitioner is further configured to obtain the selected GP line by taking the candidate GP line as the selected GP line.

18. The decoder according to claim 11, wherein the one or more candidate neighbor blocks include a default neighbor block of the current block;

and

wherein the partitioner is configured to obtain the selected GP line by taking the generated candidate GP line as the selected GP line.

19. The decoder according to claim 11, wherein the offset information comprises a step size and a quantized offset value, wherein an offset between the final GP line and the selected GP line is determined based on a product of the step size and the quantized offset value.

24. A computer program with program code means for performing all steps according to claim 11 if the program is executed on a computer or a digital signal processor.

25. A computer program product having a computer readable medium with stored program code means for performing all steps according to claim 11 if the program is executed on a computer or a digital signal processor.

20. An encoder for encoding a frame in a video sequence, comprising:

a processor, the processor being configured to;

receive a current block of the frame;

obtain a list of one or more candidate geometric partitioning (GP) lines, wherein each of the one or more candidate GP lines is generated based on information of one or more candidate neighbor blocks of the current block;

determine a final GP line that partitions the current block into two segments;

select a GP line from the list of the one or more candidate GP lines to obtain a selected GP line;

generate a GP parameter for the current block, wherein the GP parameter includes offset information indicating an offset between the final GP line and the selected GP line; and

encode the GP parameter.

21. A decoder for decoding a frame in a video sequence, comprising:

a processor, the processor being configured to;

decode an encoded geometric partitioning (GP) parameter for a current block, wherein the encoded GP parameter includes offset information indicating an offset between a final GP line and a selected GP line;

generate a list of one or more candidate GP lines, wherein each of the one or more candidate GP lines is generated based on information of each of one or more candidate neighbor blocks of the current block;

select a GP line from the list of the one or more candidate GP lines to obtain the selected GP line; and

obtain, based on the decoded GP parameter and the selected GP line, the final GP line,

wherein the final GP line partitions the current block into two segments, and

wherein the GP parameter includes offset information indicating an offset between the final GP line and the selected GP line.