Motion information encoding apparatus and encoding method, and motion information decoding apparatus and decoding method

Patent metadata

Field	Value
Publication number	US-2021266561-A1
Application number	US-201817255599-A
Country	US
Kind code	A1
Filing date	Jun 26, 2018
Priority date	Jun 26, 2018
Publication date	Aug 26, 2021
Grant date	—

Abstract

A method of decoding motion information includes determining a coding factor value of a differential motion vector of a current block, when adaptive encoding has been applied to the differential motion vector, determining a first result value generated by applying the adaptive encoding to the differential motion vector, based on information included in the bitstream, obtaining the differential motion vector by applying the determined coding factor value to the first result value according to a certain operation, and obtaining a motion vector of the current block, based on the obtained differential motion vector and a prediction motion vector of the current block.

First claim

1 . A method of decoding motion information, the method comprising:
determining a coding factor value of a differential motion vector of a current block, when adaptive encoding has been applied to the differential motion vector; determining a first result value generated by applying the adaptive encoding to the differential motion vector, based on information included in a bitstream; obtaining the differential motion vector by applying the determined coding factor value to the first result value according to a certain operation; and obtaining a motion vector of the current block, based on the obtained differential motion vector and a prediction motion vector of the current block.

2 . The method of claim 1 , wherein the determining of the first result value comprises determining a second result value generated by applying the adaptive encoding to the differential motion vector, based on information included in the bitstream, and
the obtaining of the differential motion vector comprises obtaining the differential motion vector by further applying the second result value to the certain operation.

3 . The method of claim 1 , wherein the determining of the coding factor value of the differential motion vector comprises:
obtaining factor value indicating information from the bitstream; and determining the coding factor value, based on the obtained factor value indicating information.

4 . The method of claim 1 , wherein the determining of the coding factor value of the differential motion vector comprises determining the coding factor value of the differential motion vector, based on information related to at least one of the current block, a pre-decoded block, a current slice including the current block, a pre-decoded slice, a current picture including the current block, and a pre-decoded picture.

5 . The method of claim 1 , further comprising, when the adaptive encoding is not applied to the differential motion vector of the current block, determining the differential motion vector of the current block, based on information obtained from the bitstream.

6 . The method of claim 1 , further comprising:
determining a first motion vector resolution of a first component of the motion vector of the current block and a second motion vector resolution of a second component of the motion vector of the current block; adjusting a first component value and a second component value of the prediction motion vector, based on results of comparisons between a predetermined minimum motion vector resolution and each of the first motion vector resolution and the second motion vector resolution; and obtaining the motion vector of the current block, based on the adjusted prediction motion vector and the differential motion vector.

7 . The method of claim 6 , wherein the determining of the coding factor value of the differential motion vector comprises determining the coding factor value, based on the first motion vector resolution and the second motion vector resolution.

8 . The method of claim 6 , wherein the adjusting of the first component value and the second component value of the prediction motion vector comprises adjusting the first component value of the prediction motion vector when the first motion vector resolution is greater than the minimum motion vector resolution, and adjusting the second component value of the prediction motion vector when the second motion vector resolution is greater than the minimum motion vector resolution.

9 . The method of claim 6 , wherein the determining of the first motion vector resolution and the second motion vector resolution comprises determining the first motion vector resolution and the second motion vector resolution, based on information representing the first motion vector resolution, which is obtained from the bitstream, and information representing the second motion vector resolution, which is obtained from the bitstream.

10 . The method of claim 6 , wherein the determining of the first motion vector resolution and the second motion vector resolution comprises determining the first motion vector resolution and the second motion vector resolution, based on a width and a height of the current block.

11 . The method of claim 10 , wherein the determining of the first motion vector resolution and the second motion vector resolution comprises determining the first motion vector resolution and the second motion vector resolution so that the first motion vector resolution is greater than the second motion vector resolution, when the width is larger than the height.

12 . An image decoding apparatus comprising:
an obtainer configured to obtain a bitstream; and a prediction decoder configured to determine a coding factor value of a differential motion vector of a current block, when adaptive encoding has been applied to the differential motion vector, determine a first result value generated by applying the adaptive encoding to the differential motion vector, based on information included in the bitstream, obtain the differential motion vector by applying the determined coding factor value to the first result value according to a certain operation, and obtain a motion vector of the current block, based on the obtained differential motion vector and a prediction motion vector of the current block.

13 . A method of encoding motion information, the method comprising:
obtaining a differential motion vector of a current block, based on a motion vector of the current block and a prediction motion vector of the current block; determining a coding factor value of the differential motion vector, when adaptive encoding is applied to the differential motion vector; obtaining a first result value of the differential motion vector by applying the determined coding factor value to the differential motion vector according to a certain operation; and generating a bitstream, based on the first result value of the differential motion vector.

14 . The method of claim 13 , further comprising obtaining a second result value of the differential motion vector by applying the determined coding factor value to the differential motion vector according to the certain operation, and
the generating of the bitstream comprises generating the bitstream, based on the first result value and the second result value of the differential motion vector.

15 . The method of claim 14 , wherein the determining of the coding factor value of the differential motion vector comprises, when each of a plurality of factor value candidates is applied to the differential motion vector, determining a factor value candidate causing a smallest overall number of bits of a first result value and a second result value of the differential motion vector and factor value indication information representing a factor value candidate, to be the coding factor value of the differential motion vector of the current block.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Jeong Seung-Soo
• Kim Chan-Yul
• Park Min-Soo
• Park Min-Woo
• Choi Ki-Ho
• Choi Na-Rae
• Choi Woong-Il
• Tamse Anish
• Piao Yin-Ji

Classifications

• H04N19/70

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04N19/523

  with sub-pixel accuracy · CPC title

• H04N19/52 Primary

  by predictive encoding · CPC title

• H04N19/176

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

• H04N19/147 Primary

  according to rate distortion criteria (rate-distortion as a criterion for motion estimation H04N19/567) · CPC title