BR-122025000828-B1 - VIDEO DECODING METHOD, VIDEO ENCODING METHOD, VIDEO DECODER AND VIDEO ENCODER

BR122025000828B1BR 122025000828 B1BR122025000828 B1BR 122025000828B1BR-122025000828-B1

Abstract

VIDEO DECODING METHOD, VIDEO CODING METHOD, VIDEO DECODER AND VIDEO ENCODER. This is an image decoding method according to the present invention comprising the steps of: generating a list of fusion candidates in a current block; specifying one of a plurality of fusion candidates included in the list of fusion candidates; deriving a first affine origin vector and a second affine origin vector of the current block based on a first affine origin vector and a second affine origin vector of the specified fusion candidate; deriving an affine vector for a sub-block in the current block using the first affine origin vector and the second affine origin vector of the current block; and performing motion compensation prediction for the sub-block based on the affine vector.

Inventors

BAE KEUN LEE

Assignees

GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD

Dates

Publication Date: 20260310
Application Date: 20190920
Priority Date: 20180921

Claims (8)

1. VIDEO DECODING METHOD characterized by comprising: generating a list of merge candidates for a current block; specifying a merge candidate from a plurality of merge candidates included in the list of merge candidates; deriving a first affine source vector (sv0) and a second affine source vector (sv1) from the current block based on a first affine source vector (nv0) and a second affine source vector (nv1) of a merge candidate; deriving an affine vector for a sub-block in the current block using the first affine source vector (sv0) and the second affine source vector (sv1) of the current block, wherein the sub-block is a region of a size smaller than that of the current block; To perform a motion compensation prediction for the sub-block based on the affine vector, the first affine origin vector (nv0) and the second affine origin vector (nv1) of the single merge candidate are derived based on the motion information of a neighboring block adjacent to the current block, wherein the neighboring block is included in a different coding tree unit than the current block, the first affine origin vector (nv0) and the second affine origin vector (nv1) of a merge candidate are derived based on motion vectors of a sub-block in the lower left and a sub-block in the lower right of the neighboring block, the lower left sub-block includes a lower left affine reference sample control point (xn4, yn4) positioned at a corner of the lower left of the neighboring block, and the lower right sub-block joins a lower right affine reference sample control point (xn5, yn5) located on a right side of a sample of the lower right part of the lower right sub-block; wherein the first affine origin vector and the second affine origin vector of the single merge candidate are derived from a value obtained by applying a displacement operation to a width between the lower left sub-block and the lower right sub-block, wherein the displacement operation alters the width by a scale factor.
2. METHOD, according to claim 1, characterized in that the width between the lower left sub-block and the lower right sub-block is defined as a variable, the variable being a subseed vector width that is defined as a power series of 2.
3. VIDEO CODING METHOD characterized by comprising: generating a list of merge candidates for a current block; specifying a merge candidate from a plurality of merge candidates included in the list of merge candidates; deriving a first affine source vector (sv0) and a second affine source vector (sv1) from the current block based on a first affine source vector (nv0) and a second affine source vector (nv1) of a merge candidate; deriving an affine vector for a sub-block in the current block using the first affine source vector (sv0) and the second affine source vector (sv1) of the current block, wherein the sub-block is a region of a smaller size than the current block; To perform a motion compensation prediction for the sub-block based on the affine vector, the first affine origin vector (nv0) and the second affine origin vector (nv1) of the single merge candidate are derived based on the motion information of a neighboring block adjacent to the current block, wherein the neighboring block is included in a different coding tree unit than the current block, the first affine origin vector (nv0) and the second affine origin vector (nv1) of a merge candidate are derived based on motion vectors of a sub-block in the lower left and a sub-block in the lower right of the neighboring block, the lower left sub-block includes a lower left affine reference sample control point (xn4, yn4) positioned at a corner of the lower left of the neighboring block, and the lower right sub-block joins a lower right affine reference sample control point (xn5, yn5) located on a right side of a sample of the lower right part of the lower right sub-block; wherein the first affine origin vector and the second affine origin vector of the single merge candidate are derived from a value obtained by applying a displacement operation to a width between the lower left sub-block and the lower right sub-block, wherein the displacement operation alters the width by a scale factor.
4. METHOD, according to claim 3, characterized in that the width between the lower left sub-block and the lower right sub-block is defined as a variable, the variable being a sub-seed vector width that is defined as a power-of-2 series.
5. VIDEO DECODER characterized by being configured to perform the following operations: generate a list of merge candidates for a current block; specify a merge candidate from a plurality of merge candidates included in the list of merge candidates; derive a first affine source vector (sv0) and a second affine source vector (sv1) from the current block based on a first affine source vector (nv0) and a second affine source vector (nv1) of a merge candidate; derive an affine vector for a sub-block in the current block using the first affine source vector (sv0) and the second affine source vector (sv1) of the current block, wherein the sub-block is a region of a smaller size than the current block; To perform a motion compensation prediction for the sub-block based on the affine vector, the first affine origin vector (nv0) and the second affine origin vector (nv1) of the single merge candidate are derived based on the motion information of a neighboring block adjacent to the current block, wherein the neighboring block is included in a different coding tree unit than the current block, the first affine origin vector (nv0) and the second affine origin vector (nv1) of a merge candidate are derived based on motion vectors of a sub-block in the lower left and a sub-block in the lower right of the neighboring block, the lower left sub-block includes a lower left affine reference sample control point (xn4, yn4) positioned at a corner of the lower left of the neighboring block, and the lower right sub-block joins a lower right affine reference sample control point (xn5, yn5) located on a right side of a sample of the lower right part of the lower right sub-block; wherein the first affine origin vector and the second affine origin vector of the single merge candidate are derived from a value obtained by applying a displacement operation to a width between the lower left sub-block and the lower right sub-block, wherein the displacement operation alters the width by a scale factor.
6. VIDEO DECODER, according to claim 5, characterized in that the width between the lower left sub-block and the lower right sub-block is defined as a variable, the variable being a sub-seed vector width that is defined as a power-of-2 series.
7. VIDEO ENCODER characterized by being configured to perform the following operations: generate a list of merge candidates for a current block; specify a merge candidate from a plurality of merge candidates included in the list of merge candidates; derive a first affine source vector (sv0) and a second affine source vector (sv1) from the current block based on a first affine source vector (nv0) and a second affine source vector (nv1) of a merge candidate; derive an affine vector for a sub-block in the current block using the first affine source vector (sv0) and the second affine source vector (sv1) of the current block, wherein the sub-block is a region of a smaller size than the current block; To perform a motion compensation prediction for the sub-block based on the affine vector, the first affine origin vector (nv0) and the second affine origin vector (nv1) of the single merge candidate are derived based on the motion information of a neighboring block adjacent to the current block, wherein the neighboring block is included in a different coding tree unit than the current block, the first affine origin vector (nv0) and the second affine origin vector (nv1) of a merge candidate are derived based on motion vectors of a sub-block in the lower left and a sub-block in the lower right of the neighboring block, the lower left sub-block includes a lower left affine reference sample control point (xn4, yn4) positioned at a corner of the lower left of the neighboring block, and the lower right sub-block joins a lower right affine reference sample control point (xn5, yn5) located on a right side of a sample of the lower right part of the lower right sub-block; wherein the first affine origin vector and the second affine origin vector of the single merge candidate are derived from a value obtained by applying a displacement operation to a width between the lower left sub-block and the lower right sub-block, wherein the displacement operation alters the width by a scale factor.
8. VIDEO ENCODER, according to claim 7, characterized in that the width between the lower left sub-block and the lower right sub-block is defined as a variable, the variable being a sub-seed vector width that is defined as a power-of-2 series.

Description

This patent application consists of a split application of the invention patent application BR 112021004922-3, dated 09/20/2019. BACKGROUND OF THE INVENTION FIELD OF THE INVENTION [001] The present invention relates to a method of encoding and decoding video signals and an apparatus for the same. BACKGROUND OF THE RELATED TECHNIQUE [002] As display panels become increasingly larger, ever higher quality video services are increasingly needed. The biggest problem with high-definition video services is the significant increase in data volume, and to solve this problem, studies to improve video compression rates are actively being carried out. As a representative example, the Motion Picture Experts Group (MPEG) and the Video Coding Experts Group (VCEG) under the International Telecommunication Union-Telecommunication (ITU-T) formed the Joint Collaborative Team on Video Coding (JCT-VC) in 2009. The JCT-VC proposed High Efficiency Video Coding (HEVC), which is a video compression standard with a compression performance approximately twice that of H.264/AVC, and was approved as a standard on January 25, 2013. With the rapid advancement in high-definition video services, the performance of HEVC is gradually revealing its limitations. SUMMARY OF THE INVENTION [003] An object of the present invention is to provide an interprediction method using an affine model, and an apparatus for the same, in the encoding/decoding of a video signal. [004] Another object of the present invention is to provide a method for deriving an affine origin vector using a translational motion vector of a sub-block, and an apparatus for carrying out the method, in the encoding/decoding of a video signal. [005] Another object of the present invention is to provide a method for deriving an affine origin vector by transforming a distance between a neighboring block and a current block into a power-of-2 series, and an apparatus for carrying out the method, in the encoding/decoding of a video signal. [006] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the following description. [007] A method for decoding and encoding a video signal according to the present invention includes the steps of: generating a list of fusion candidates for a current block; specifying one from a plurality of fusion candidates included in the list of fusion candidates; deriving a first affine origin vector and a second affine origin vector of the current block based on a first affine origin vector and a second affine origin vector of the specified fusion candidate; deriving an affine vector for a sub-block in the current block by using the first affine origin vector and the second affine origin vector of the current block; and performing a motion compensation prediction for the sub-block based on the affine vector. At this point, the sub-block is a region of a smaller size than that of the current block. Furthermore, the first affine origin vector and the second affine origin vector of the fusion candidate can be derived based on motion information from a neighboring block adjacent to the current block. [008] In the method of decoding and encoding a video signal according to the present invention, when the neighboring block is included in a different encoding tree unit than the current block's encoding tree unit, the first affine origin vector and the second affine origin vector of the fusion candidate can be derived based on motion vectors of a lower left sub-block and a lower right sub-block of the neighboring block. [009] In the method of decoding and encoding a video signal according to the present invention, the lower left sub-block may include a lower left reference sample positioned in a lower left corner of the neighboring block, and the lower right sub-block may include a lower right reference sample located in a lower left corner of the neighboring block. [0010] In the method of decoding and encoding a video signal according to the present invention, the first affine origin vector and the second affine origin vector of the fusion candidate can be derived based on a value obtained from a compensation operation performed on a difference value between motion vectors of the lower left sub-block and the lower right sub-block using a scaling factor, and the scaling factor can be derived based on a value obtained by adding a horizontal distance between the lower left reference sample and the lower right reference sample and an offset. [0011] In the method of decoding and encoding a video signal according to the present invention, the first affine origin vector and the second affine origin vector of the fusion candidate can be derived based on a value obtained based on a compensation operation performed on a difference value between motion vectors of the lower left sub-block and the lower right sub-block us