# US 2020/0396458 A1 · Method and device for predictive picture encoding and decoding

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- Number: US 2020/0396458 A1
- Document ID: US20200396458A1
- Status: Published application
- Kind: A1
- Application number: 16/603,568
- Filed: 2018-03-15
- Published: 2020-12-17
- Earliest claimed: 2017-04-07
- Assignees: InterDigital VC Holdings, Inc.
- Applicants: Interdigital Vc Holdings, Inc.
- Inventors: Edouard FRANCOIS; Christophe CHEVANCE; Franck HIRON
- Web page: https://patentgrep.com/patent/US20200396458A1

## CPC

- H04N 19/132: Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
- H04N 19/182: the unit being a pixel
- H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635)
- H04N 19/136: Incoming video signal characteristics or properties
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/186: the unit being a colour or a chrominance component
- H04N 19/196: being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513)
- H04N 19/50: using predictive coding (H04N19/61 takes precedence)
- H04N 19/82: involving filtering within a prediction loop
- H04N 19/126: Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
- H04N 19/61: in combination with predictive coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A method for encoding a block of a picture is disclosed. The method comprises for at least one sample of the block and for one current component:—obtaining a prediction value;—determining a mapped residual value from a source value of the sample and from the prediction value responsive to a mapping function; and—encoding the mapped residual value into a bitstream; wherein the mapping function is derived to obtain at least one of a reduction of a bit cost of the bitstream for a given quality of reconstruction or an increase of quality of reconstruction for a given bit cost of the bitstream.

## Claims

### Claim 1

A method for encoding, comprising:
obtaining a prediction value of a current color component of a sample of a block of a picture;
determining a mapped residual value from a source value of said current color component and from the prediction value to using a mapping function; and
encoding the mapped residual value into a bitstream;
wherein determining the mapped residual value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value;
determining an intermediate residual value representative of a difference between the mapped prediction value and the source value; and
mapping the intermediate residual value to using the mapping function.

### Claim at position 2

2-4. (canceled)

### Claim 5

A method for decoding, comprising:
obtaining a prediction value of a current color component of a sample of a block of a picture;
decoding a residual value for the sample;
determining a reconstructed value for the sample from the decoded residual value and from the prediction value to using both a mapping function and an inverse mapping function that is the inverse of the mapping function;
wherein determining the reconstructed value comprises:
mapping the prediction value with an the mapping function to obtain a mapped prediction value; and
obtaining an intermediate value representative of a sum of the mapped prediction value and the residual value;
the reconstructed value being obtained by mapping the intermediate value with the inverse mapping function.

### Claim at position 4

6-8. (canceled)

### Claim 9

A device for encoding, comprising electronic circuitry adapted for:
obtaining a prediction value of a current color component of at least a sample of a block of a picture;
determining a mapped residual value from a source value of said current color component and from the prediction value using a mapping function; and
encoding the mapped residual value into a bitstream;
wherein the determining of the mapped residual value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value;
determining an intermediate residual value representative of a difference between the mapped prediction value and the source value; and
mapping the intermediate residual value using the mapping function.

### Claim at position 6

10-12. (canceled)

### Claim 13

A device for decoding, comprising electronic circuitry adapted for:
obtaining a prediction value of a current color component of a sample of the a block of a picture;
decoding a residual value for the sample;
determining a reconstructed value for the sample from the decoded residual value and from the prediction value using both a mapping function and an inverse mapping function that is the inverse of the mapping function;
wherein the determining of the reconstructed value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value; and,
obtaining an intermediate value representative of a sum of mapped prediction value and the residual value;
the reconstructed value being obtained by mapping the intermediate value with the inverse mapping function.

### Claim at position 8

14-16. (canceled)

### Claim 17 (depends on 9)

An apparatus comprising the device according to claim 9.

### Claim 18 (depends on 13)

An apparatus comprising the device according to claim 13.

### Claim 19

A signal comprising data generated by a method for encoding comprising:
obtaining a prediction value of a current color component of a sample of a block of a picture;
determining a mapped residual value from a source value of said current color component and from the prediction value using a mapping function; and
encoding the mapped residual value into a bitstream;
wherein determining the mapped residual value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value;
determining an intermediate residual value representative of a difference between the mapped prediction value and the source value; and
mapping the intermediate residual value using the mapping function.

### Claim 20

A signal comprising data generated by a method for decoding comprising:
obtaining a prediction value of a current color component of a sample of a block of a picture;
decoding a residual value for the sample;
determining a reconstructed value for the sample from the decoded residual value and from the prediction value using both a mapping function and an inverse mapping function that is the inverse of the mapping function;
wherein determining the reconstructed value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value; and,
obtaining an intermediate value representative of a sum of the mapped prediction value and the residual value;
the reconstructed value being obtained by mapping the intermediate value with the inverse mapping function.

### Claim 21

A non-transitory information storage medium storing program code instructions for implementing a method for encoding comprising:
obtaining a prediction value of a current color component of a sample of a block of a picture;
determining a mapped residual value from a source value of said current color component and from the prediction value using a mapping function; and
encoding the mapped residual value into a bitstream;
wherein determining the mapped residual value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value;
determining an intermediate residual value representative of a difference between the mapped prediction value and the source value; and
mapping the intermediate residual value using the mapping function.

### Claim 22

A non-transitory information storage medium storing program code instructions for implementing a method for decoding comprising:
obtaining a prediction value of a current color component of a sample of a block of a picture;
decoding a residual value for the sample;
determining a reconstructed value for the sample from the decoded residual value and from the prediction value using both a mapping function and an inverse mapping function that is the inverse of the mapping function;
wherein determining the reconstructed value comprises:
mapping the prediction value with the mapping function to obtain a mapped prediction value; and,
obtaining an intermediate value representative of a sum of the mapped prediction value and the residual value;
the reconstructed value being obtained by mapping the intermediate value with the inverse mapping function.