# US 9,438,921 B2 · Video encoding method using offset adjustments according to pixel classification and apparatus therefor, video decoding method and apparatus therefor

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- Number: US 9,438,921 B2
- Document ID: US9438921B2
- Status: Granted
- Kind: B2
- Application number: 14/603,020
- Filed: 2015-01-22
- Published: 2015-05-14
- Granted: 2016-09-06
- Earliest claimed: 2011-06-28
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Elena Alshina; Alexander Alshin
- Web page: https://patentgrep.com/patent/US9438921B2

## CPC

- H04N 19/463: by compressing encoding parameters before transmission
- H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635)
- H04N 19/137: Motion inside a coding unit, e.g. average field, frame or block difference
- H04N 19/14: Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence)
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/182: the unit being a pixel
- H04N 19/186: the unit being a colour or a chrominance component
- H04N 19/189: characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding
- H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
- H04N 19/50: using predictive coding (H04N19/61 takes precedence)
- H04N 19/625: using discrete cosine transform [DCT]
- H04N 19/85: using pre-processing or post-processing specially adapted for video compression
- H04N 19/89: involving methods or arrangements for detection of transmission errors at the decoder
- H04N 19/90: using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A video encoding method and apparatus and video decoding method and apparatus generate a restored image having a minimum error with respect to an original image based on offset merge information indicating whether offset parameters of a current block and at least one neighboring block from among blocks of video are identical.

## Claims

### Claim 1

A video decoding method comprising:
parsing, from a bitstream, offset merge information indicating whether a sample offset parameter of a current block is derived from a sample offset parameter of a neighboring block;
when the offset merge information indicates that the sample offset parameter of the current block is derived from the sample offset parameter of the neighboring block, determining the sample offset parameter of the current block using the sample offset parameter of the neighboring block;
when the offset merge information indicates that the sample offset parameter of the current block is not derived from the sample offset parameter of the neighboring block, obtaining, from the bitstream, a plurality of offset values and information about an offset type of the current block; and
compensating for a sample value of a current sample among samples of the current block, by using an offset value for the current sample among the plurality of offset values of the current block,
wherein:
when the information about an offset type indicates an edge offset type, the obtaining a plurality of offset values comprises further obtaining, from the bitstream, information about a particular edge direction of the current block among a plurality of edge directions,
the plurality of offset values of the current block correspond to a plurality of edge classes,
two neighboring samples, among samples adjacent to the current sample, are determined corresponding to the particular edge direction of the current block,
an edge class for the current sample, among the plurality of edge classes, is determined according to whether the current sample is larger than the two neighboring samples, and
the offset value for the current sample is determined, among the plurality of offset values of the current block, according to the edge class for the current sample, and
wherein, when the information about an offset type indicates a band offset type, the obtaining a plurality of offset values comprises:
obtaining, from the bitstream, a plurality of absolute values of the offset values; and
when the absolute values of the offset values are not zero, obtaining, from the bitstream, a plurality of signs of the offset values.

### Claim 2 (depends on 1)

The video decoding method of claim 1, wherein, when the offset merge information indicates that the sample offset parameter of the current block is derived from the sample offset parameter of the neighboring block, the sample offset parameter of the current block is not parsed from the bitstream, and
the neighboring block is one of a left block and an upper block of the current block.

### Claim 3 (depends on 1)

The video decoding method of claim 1, wherein
the information about a particular edge direction of the current block indicates one among 0°, 45°, 90° and 135°.