# US 9,438,919 B2 · Intra prediction apparatus

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- Number: US 9,438,919 B2
- Document ID: US9438919B2
- Status: Granted
- Kind: B2
- Application number: 14/929,544
- Filed: 2015-11-02
- Published: 2016-02-25
- Granted: 2016-09-06
- Earliest claimed: 2010-07-31
- Assignees: M&K Holdings Inc.
- Applicants: M & K Holdings Inc.
- Inventors: Soo Mi Oh; Moonock Yang
- Web page: https://patentgrep.com/patent/US9438919B2

## CPC

- H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635)
- H04N 19/124: Quantisation
- H04N 19/13: Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
- H04N 19/157: Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
- H04N 19/17: the unit being an image region, e.g. an object
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/182: the unit being a pixel
- H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
- H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence)
- H04N 19/50: using predictive coding (H04N19/61 takes precedence)
- H04N 19/593: involving spatial prediction techniques
- H04N 19/61: in combination with predictive coding
- H04N 19/82: involving filtering within a prediction loop
- H04N 19/91: Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

Provided is an intra prediction apparatus that adaptively filters reference pixels according to an intra prediction mode and a size of a prediction block, and generates the prediction block according to the intra prediction mode. When the reference pixels for a second directional intra prediction mode are filtered, the reference pixels for a first directional intra prediction mode, that is closer to an intra prediction mode having a direction of 45° with reference to a horizontal mode than the second directional intra prediction mode is, are also filtered. The first and the second intra prediction modes exist between the horizontal mode and the intra prediction mode having the direction of 45° with reference to the horizontal mode. The number of intra prediction modes in which the filter is applied increases as the size of the prediction block increases.

## Claims

### Claim 1

An intra prediction apparatus, the apparatus comprising:
a reference pixel generator configured to generate reference pixels when one or more unavailable reference pixels exist, and to adaptively filter reference pixels according to an intra prediction mode and a size of a prediction block;
a prediction block generator configured to generate the prediction block using reference pixels determined by the intra prediction mode; and
a prediction block post-processor configured to adaptively filter a part of the prediction block using the intra prediction mode,
wherein the reference pixel generator adaptively filters the reference pixels according to the size of the prediction block for intra prediction modes existing between a horizontal mode and an intra prediction mode having a direction of 45° with reference to the horizontal mode,
wherein, when the reference pixel generator filters the reference pixels for a second directional intra prediction mode, the reference pixel generator also filters the reference pixels for a first directional intra prediction mode that is closer to the intra prediction mode having the direction of 45° with reference to the horizontal mode than the second directional intra prediction mode is,
wherein the second and the first directional intra prediction modes exist between the horizontal mode and the intra prediction mode having the direction of 45° with reference to the horizontal mode, and
wherein the number of intra prediction modes in which the filter is applied increases as the size of the prediction block increases.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the reference pixel generator does not filter the reference pixels when the size of the prediction block is smaller than a predetermined block size.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein, when the intra prediction mode is a planar mode, the reference pixel generator generates the prediction block using a corner reference pixel, a left reference pixel and an upper reference pixel.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein, when the intra prediction mode is a vertical mode, the reference pixel generator does not filter the reference pixels and the prediction block filter filters the prediction block using the reference pixels not used for generating the prediction block.