# US 2014/0192891 A1 · 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 2014/0192891 A1
- Document ID: US20140192891A1
- Status: Published application
- Kind: A1
- Application number: 14/130,011
- Filed: 2012-06-27
- Published: 2014-07-10
- Earliest claimed: 2011-06-28
- Assignees: Samsung Electronics Co., Ltd.
- Inventors: Elena Alshina; Alexander Alshin
- Web page: https://patentgrep.com/patent/US20140192891A1

## 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 offset parameters of a current block and offset parameters of at least one neighboring block adjacent to the current block are identical;
restoring an offset type and offset values of the current block from the offset parameter of the current block based on the offset merge information;
determining an edge class or a pixel value band of a restored pixel of the current block based on an edge type or a pixel value band type of the current block indicating the offset type; and
determining an offset value corresponding to the edge class or the pixel value band of the restored pixel from the restored offset values of the current block and adjusting a pixel value of the restored pixel of the current block according to the restored offset values of the current block.

### Claim 2 (depends on 1)

The video decoding method of claim 1, wherein the determining of the edge class or the pixel value band of the restored pixel comprises:
in a case where the offset type of the current block is the edge type, comparing pixel values of the restored pixel of the current block and neighboring pixels adjacent to the restored pixel of the current block disposed according to the edge type and an edge size, and determining the edge class indicating whether the currently restored pixel is an edge pixel, and
wherein the adjusting of the pixel value of the restored pixel of the current block according to the offset value comprises:
in a case where the offset values comprise offset values corresponding to edge classes allocated to a current offset type, determining an offset value corresponding to an edge class of the restored pixel of the current block from the offset values.

### Claim 3 (depends on 1)

The video decoding method of claim 1, wherein the determining of the edge class or the pixel value band of the restored pixel of the current block comprises:
in a case where the offset type of the current block is the pixel value band type, determining the pixel value band indicating a pixel value range to which the pixel value of the restored pixel of the current block belong among a plurality of bands,
wherein the adjusting of the pixel value of the restored pixel according to the offset value comprises:
in a case where the offset values comprise offset values corresponding to pixel value bands allocated to a current offset type, determining an offset value corresponding to a pixel value band of the restored pixel of the current block from the offset values.

### Claim 4 (depends on 1)

The video decoding method of claim 1, wherein the restoring of the offset type and the offset values comprises: if at least one offset parameter of a left block and an upper block of the current block is identical to the offset parameter of the current block based on the offset merge information, restoring the offset parameter of the current block to be the same as the at least one offset parameter of the left block and the upper block of the current block.

### Claim 5 (depends on 1)

The video decoding method of claim 1, wherein the restoring of the offset type and the offset values comprises: if at least one offset parameter of a left block and an upper block of the current block is different from the offset parameter of the current block based on the offset merge information, parsing and restoring the offset parameter of the current block from the received bitstream.

### Claim 6 (depends on 1)

The video decoding method of claim 1, wherein the restoring of the offset type and the offset values comprises: performing prediction and restoration on offset parameters of at least one of a luma component by referring to offset parameters of a chroma component among the offset parameters and the chroma component by referring to offset parameters of the luma component among the offset parameters.

### Claim 7 (depends on 1)

The video decoding method of claim 1, wherein the offset value is an average of difference values between restored pixels and original pixels included in the same edge class or the same pixel value band.

### Claim 8

A video encoding method comprising:
determining an edge class according to an edge type of a current block from among blocks of video or a pixel value band according to a pixel value band type of the current block;
determining an offset value corresponding to the edge class or the pixel value band based on difference values between restored pixels and original pixels included in the edge class or the pixel value band; and
when an offset parameter of each block comprises an offset type indicating the edge type or the pixel value band type and an offset corresponding to the edge class or the pixel value band, based on identities between offset parameters of the current block and offset parameters of at least one neighboring block adjacent to the current block, encoding offset merge information of the current block indicating whether the offset parameter of the current block is encoded.

### Claim 9 (depends on 8)

The video encoding method of claim 8, wherein the determining of the edge class and the pixel value band comprises: in a case where an offset of the current block is determined according to the edge type, comparing pixel values of a currently restored pixel and neighboring pixels adjacent to the currently restored pixel disposed according to the edge type and an edge size, and determining the edge class indicating whether the currently restored pixel is an edge pixel.

### Claim 10 (depends on 8)

The video encoding method of claim 8, wherein the determining of the edge class and the pixel value band comprises: in a case where an offset of the current block is determined according to pixel value band types of the restored pixels, determining the pixel value band indicating a pixel value range to which a pixel value of a currently restored pixel belong from among a plurality of bands.

### Claim 11 (depends on 8)

The video encoding method of claim 8, wherein the encoding of the offset merge information of the current block comprises: if at least one offset parameter of a left block and an upper block of the current block is identical to the offset parameter of the current block, encoding the offset merge information excluding the offset parameter of the current block.

### Claim 12 (depends on 8)

The video encoding method of claim 8, wherein the determining of the offset value corresponding to the edge class or the pixel value band comprises: determining the offset value that is an average of difference values between restored pixels and original pixels included in the same edge class or the same pixel value band.

### Claim 13

A video decoding apparatus comprising:
an offset parameter parsing unit configured to parse from a bitstream offset merge information indicating whether offset parameters of a current block and offset parameters of at least one neighboring block adjacent to the current block are identical, and to restore an offset type and offset values of the current block from the offset parameter of the current block based on the offset merge information; and
an offset adjusting unit configured to determine an edge class or a pixel value band of a restored pixel based on an edge type or a pixel value band type of the current block indicating the offset type, and to determine an offset value corresponding to the edge class or the pixel value band of the restored pixel from the restored offset values of the current block and to adjust a pixel value of the restored pixel of the current block according to the restored offset values of the current block.

### Claim 14

A video encoding apparatus comprising:
an offset determining unit configured to determine an edge class according to an edge type of a current block from among blocks of video or a pixel value band according to a pixel value band type of the current block, and to determine an offset value corresponding to the edge class or the pixel value band based on difference values between restored pixels and original pixels included in the edge class or the pixel value band; and
an offset parameter encoding unit configured to, when an offset parameter of each block comprises an offset type indicating the edge type or the pixel value band type and an offset corresponding to the edge class or the pixel value band, based on identities between offset parameters of the current block and offset parameters of at least one neighboring block adjacent to the current block, encode offset merge information of the current block indicating whether the offset parameter of the current block is encoded.

### Claim 15 (depends on 1)

A computer readable recording medium having recorded thereon a program for executing the method of claim 1.

### Claim 16 (depends on 8)

A computer readable recording medium having recorded thereon a program for executing the method of claim 8.