US-20260129209-A1 - VIDEO SIGNAL PROCESSING METHOD AND DEVICE

Abstract

According to the present invention, there is provided a method of decoding an image, the method including: deriving an initial motion vector of a current block; determining a motion refinement vector of the current block; and determining a motion vector of the current block on the basis of the initial motion vector and the motion refinement vector. Herein, the initial motion vector is derived from any one of merge candidates included in a merge candidate list for the current block.

Inventors

• Bae Keun Lee

Assignees

• KT CORPORATION

Dates

Publication Date

20260507

Application Date

20251008

Priority Date

20180327

Claims (8)

1. 1 - 15 . (canceled)
2. 16 . A method of decoding an image, the method comprising: deriving a motion vector candidate based on a neighboring block adjacent to a current block; obtaining a modified motion vector by modifying the motion vector candidate; and obtaining a prediction block of the current block based on the modified motion vector, wherein the modified motion vector is obtained by adjusting the motion vector candidate to a motion vector resolution of the current block.
3. 17 . The method of claim 16 , wherein the modified motion vector is obtained by a round down operation with the motion vector candidate.
4. 18 . The method of claim 16 , wherein the modified motion vector is obtained by increasing the motion vector resolution of the selected motion vector candidate to a motion vector resolution of the current block.
5. 19 . The method of claim 18 , wherein the motion vector resolution of the current block selected from a plurality of motion vector resolution candidates, and wherein the motion vector resolution candidates comprise at least one of integer-pel, ½-pel, ¼-pel, ⅛ pel or 1/16-pel.
6. 20 . The method of claim 19 , wherein obtaining the modified motion vector by adjusting the motion vector candidate is allowed only in a pre-defined inter prediction mode among a plurality of inter prediction modes, the plurality of inter prediction modes comprising a merge mode and an AMVP (Advanced Motion Vector Prediction) mode.
7. 21 . A method of encoding an image, the method comprising: deriving a motion vector candidate based on a neighboring block adjacent to a current block; obtaining a modified motion vector by modifying the motion vector candidate; and obtaining a prediction block of the current block based on the modified motion vector, wherein the modified motion vector is obtained by adjusting the motion vector candidate to a motion vector resolution of the current block.
8. 22 . A device for transmitting compressed video data, comprising: a processor configured to obtain the compressed video data; and a transmitter configured to transmit the compressed video data, wherein obtaining the compressed video data comprises: deriving a motion vector candidate based on a neighboring block adjacent to a current block; obtaining a modified motion vector by modifying the motion vector candidate; and obtaining a prediction block of the current block based on the modified motion vector, wherein the modified motion vector is obtained by adjusting the motion vector candidate to a motion vector resolution of the current block.

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for processing video signal. BACKGROUND ART Recently, demands for high-resolution and high-quality images such as high definition (HD) images and ultra-high definition (UHD) images have increased in various application fields. However, higher resolution and quality image data has increasing amounts of data in comparison with conventional image data. Therefore, when transmitting image data by using a medium such as conventional wired and wireless broadband networks, or when storing image data by using a conventional storage medium, costs of transmitting and storing increase. In order to solve these problems occurring with an increase in resolution and quality of image data, high-efficiency image encoding/decoding techniques may be utilized. Image compression technology includes various techniques, including: an inter-prediction technique of predicting a pixel value included in a current picture from a previous or subsequent picture of the current picture; an intra-prediction technique of predicting a pixel value included in a current picture by using pixel information in the current picture; an entropy encoding technique of assigning a short code to a value with a high appearance frequency and assigning a long code to a value with a low appearance frequency; etc. Image data may be effectively compressed by using such image compression technology, and may be transmitted or stored. In the meantime, with demands for high-resolution images, demands for stereographic image content, which is a new image service, have also increased. A video compression technique for effectively providing stereographic image content with high resolution and ultra-high resolution is being discussed. DISCLOSURE Technical Problem An objective of the present invention is to provide a method and apparatus for effectively performing inter-prediction on an encoding/decoding target block when encoding/decoding a video signal. Another objective of the present invention is to provide a method and apparatus for performing motion compensation by using a plurality of merge candidate list when encoding/decoding a video signal. Another objective of the present invention is to provide a method and a device for refining a motion vector acquired from a merge candidate in encoding/decoding a video signal. Technical problems obtainable from the present invention are non-limited the above-mentioned technical task, and other unmentioned technical tasks can be clearly understood from the following description by those having ordinary skill in the technical field to which the present invention pertains. Technical Solution According to the present invention, there is provided a method and a device for decoding a video signal, wherein an initial motion vector of a current block is derived, a motion refinement vector of the current block is determined, and a motion vector of the current block is determined on the basis of the initial motion vector and the motion refinement vector. Herein, the initial motion vector is derived from any one of merge candidates included in a merge candidate list for the current block. According to the present invention, there is provided a method and a device for encoding a video signal, wherein an initial motion vector of a current block is derived, a motion refinement vector of the current block is determined, and a motion vector of the current block is determined on the basis of the initial motion vector and the motion refinement vector. Herein, the initial motion vector is derived from any one of merge candidates included in a merge candidate list for the current block. In the method and the device for encoding/decoding the video signal according to the present invention, information for determining the motion refinement vector may be encoded/decoded. In the method and the device for encoding/decoding the video signal according to the present invention, the information may include size information of the motion refinement vector, and direction information of the motion refinement vector. In the method and the device for encoding/decoding the video signal according to the present invention, the size information may indicate any one of multiple candidates, and the multiple candidates may be determined on the basis of resolution of a motion vector of the current block. In the method and the device for encoding/decoding the video signal according to the present invention, a merge refinement vector may be determined on the basis of a result of searching a search region including a position indicated by the initial motion vector, for a region in which a rate-distortion cost value is the lowest. In the method and the device for encoding/decoding the video signal according to the present invention, a vector from the initial motion vector to a position of the region in which the rate-distortion cost value is the lowest may be determined as the merge refinement