# US 11,310,493 B2 · Image coding method, image decoding method, image coding apparatus, image decoding apparatus, and image coding and decoding apparatus

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- Number: US 11,310,493 B2
- Document ID: US11310493B2
- Status: Granted
- Kind: B2
- Application number: 17/101,022
- Filed: 2020-11-23
- Published: 2021-03-11
- Granted: 2022-04-19
- Earliest claimed: 2010-12-28
- Assignees: Sun Patent Trust
- Applicants: Sun Patent Trust
- Inventors: Toshiyasu Sugio; Takahiro Nishi; Youji Shibahara; Hisao Sasai
- Web page: https://patentgrep.com/patent/US11310493B2

## CPC

- H04N 19/107: between spatial and temporal predictive coding, e.g. picture refresh
- H04N 19/105: 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
- H04N 19/124: Quantisation
- H04N 19/137: Motion inside a coding unit, e.g. average field, frame or block difference
- H04N 19/139: Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
- H04N 19/172: the region being a picture, frame or field
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence)
- H04N 19/52: by predictive encoding
- H04N 19/56: Motion estimation with initialisation of the vector search, e.g. estimating a good candidate to initiate a search
- H04N 19/567: Motion estimation based on rate distortion criteria
- H04N 19/573: Motion compensation with multiple frame prediction using two or more reference frames in a given prediction direction
- H04N 19/577: Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
- H04N 19/58: Motion compensation with long-term prediction, i.e. the reference frame for a current frame not being the temporally closest one (H04N19/23 takes precedence)
- H04N 19/61: in combination with predictive coding
- H04N 19/51: Motion estimation or motion compensation
- H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

An image coding method includes: adding, to a candidate list, a first adjacent motion vector as a candidate for a predicted motion vector to be used for coding the current motion vector; selecting the predicted motion vector from the candidate list; and coding the current motion vector, wherein in the adding, the first adjacent motion vector indicating a position in a first reference picture included in a first reference picture list is added to the candidate list for the current motion vector indicating a position in a second reference picture included in a second reference picture list.

## Claims

### Claim 1

An image decoding apparatus of decoding a current picture per block with prediction using a current reference picture for a current block, the current reference picture being referred to by a current motion vector, the image decoding apparatus comprising:
a processor; and
a non-transitory memory storing thereon a program, which when executed by the processor, causes the processor to:
judging whether or not a first current reference picture for the current block is identical to a first adjacent reference picture for a first adjacent block adjacent to the current block, the first adjacent reference picture being referred to by a first adjacent motion vector;
judging whether or not a second current reference picture is identical to either one of (i) the first adjacent reference picture or (ii) a second adjacent reference picture for a second adjacent block adjacent to the current block, the second adjacent reference picture being referred to by a second adjacent motion vector;
when the second current reference picture is judged to be identical to the first adjacent reference picture, adding the first adjacent motion vector to a candidate list for a second current motion vector;
when the second current reference picture is judged to be identical to the second adjacent reference picture, adding the second adjacent motion vector to the candidate list for the second current motion vector;
selecting a predicted motion vector to be used for decoding the second current motion vector from the candidate list for second current motion vector; and
decoding the second current motion vector using the selected predicted motion vector,
wherein when the second current reference picture is judged to not be identical to the first adjacent reference picture, the first adjacent motion vector is not added to the candidate list for the second current motion vector, and
wherein when the second current reference picture is judged to not be identical to the second adjacent reference picture, the second adjacent motion vector is not added to the candidate list for the second current motion vector.

### Claim 2

An image coding and decoding system comprising:
an image coding apparatus of coding a first current picture per block with prediction using a current reference picture for a first current block, the current reference picture for the first block being referred to by a current motion vector; and
an image decoding apparatus of decoding a second current picture per block with prediction using a current reference picture for a second current block, the current reference picture for the second block being referred to by a current motion vector,
wherein the image coding apparatus comprises:
a first processor; and
a first non-transitory memory storing thereon a first program, which when executed by the first processor, causes the first processor to:
judging whether or not a first current reference picture for the first current block is identical to a first adjacent reference picture for a first adjacent block adjacent to the first current block, the first adjacent reference picture being referred to by a first adjacent motion vector;
judging whether or not a second current reference picture is identical to either one of (i) the first adjacent reference picture or (ii) a second adjacent reference picture for a second adjacent block adjacent to the first current block, the second adjacent reference picture being referred to by a second adjacent motion vector;
when the second current reference picture is judged to be identical to the first adjacent reference picture, adding the first adjacent motion vector to a candidate list for a second current motion vector;
when the second current reference picture is judged to be identical to the second adjacent reference picture, adding the second adjacent motion vector to the candidate list for the second current motion vector;
selecting a first predicted motion vector to be used for coding the second current motion vector from the candidate list for second current motion vector; and
coding the second current motion vector using the selected first predicted motion vector,
wherein when the second current reference picture is judged to not be identical to the first adjacent reference picture, the first adjacent motion vector is not added to the candidate list for the second current motion vector, and
wherein when the second current reference picture is judged to not be identical to the second adjacent reference picture, the second adjacent motion vector is not added to the candidate list for the second current motion vector,
wherein the image decoding apparatus comprising:
a second processor; and
a second non-transitory memory storing thereon a second program, which when executed by the second processor, causes the second processor to:
judging whether or not a third current reference picture for the second current block is identical to a third adjacent reference picture for a third adjacent block adjacent to the second current block, the third adjacent reference picture being referred to by a third adjacent motion vector;
judging whether or not a fourth current reference picture is identical to either one of (i) the third adjacent reference picture or (ii) a fourth adjacent reference picture for a fourth adjacent block adjacent to the second current block, the fourth adjacent reference picture being referred to by a fourth adjacent motion vector;
when the fourth current reference picture is judged to be identical to the third adjacent reference picture, adding the third adjacent motion vector to a candidate list for a fourth current motion vector;
when the fourth current reference picture is judged to be identical to the fourth adjacent reference picture, adding the fourth adjacent motion vector to the candidate list for the fourth current motion vector;
selecting a second predicted motion vector to be used for decoding the fourth current motion vector from the candidate list for fourth current motion vector; and
decoding the fourth current motion vector using the selected second predicted motion vector,
wherein when the fourth current reference picture is judged to not be identical to the third adjacent reference picture, the third adjacent motion vector is not added to the candidate list for the fourth current motion vector, and
wherein when the fourth current reference picture is judged to not be identical to the fourth adjacent reference picture, the fourth adjacent motion vector is not added to the candidate list for the fourth current motion vector.