# US 2014/0192873 A1 · Image encoding/decoding method and apparatus for same

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- Number: US 2014/0192873 A1
- Document ID: US20140192873A1
- Status: Published application
- Kind: A1
- Application number: 14/202,943
- Filed: 2014-03-10
- Published: 2014-07-10
- Earliest claimed: 2011-06-20
- Assignees: Electronics and Telecommunications Research Institute
- Applicants: Electronics and Telecommunications Research Institute
- Inventors: Jin Ho LEE; Hui Yong KIM; Sung Chang LIM; Jin Soo CHOI; Jin Woong KIM
- Web page: https://patentgrep.com/patent/US20140192873A1

## CPC

- H04N 19/593: involving spatial prediction techniques
- 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 19/11: among a plurality of spatial predictive coding modes
- H04N 19/117: Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635)
- H04N 19/122: Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
- H04N 19/136: Incoming video signal characteristics or properties
- H04N 19/137: Motion inside a coding unit, e.g. average field, frame or block difference
- 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 19/159: Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
- 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 19/80: Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation (H04N19/635, H04N19/86 take precedence)
- H04N 19/82: involving filtering within a prediction loop
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/96: Tree coding, e.g. quad-tree coding
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

According to the present invention, an image encoding/decoding method comprises the steps of: performing an intra prediction on a current block so as to generate a prediction block; performing filtering on a filtering target pixel in the prediction block on the basis of the intra prediction mode of the current block so as to generate a final prediction block; and generating a reconstructed block on the basis of a reconstructed differential block corresponding to the current block and on the final prediction block. According to the present invention, image encoding/decoding efficiency can be improved.

## Claims

### Claim 1

A video encoding apparatus comprising:
a prediction block generating unit to generate a prediction block by performing intra prediction on a current block using a DC mode and to generate a final prediction block by performing filtering on a filtering target pixel in the prediction block; and
a reconstructed block generating unit to generate a reconstructed block based on the final prediction block and a reconstructed residual block corresponding to the current block,
wherein a filtering target pixel comprises a left vertical prediction pixel line that is one vertical pixel line positioned at a leftmost side of the prediction block and an upper horizontal prediction pixel line that is one horizontal pixel line positioned at an uppermost side of the prediction block.

### Claim 2 (depends on 1)

The video encoding apparatus of claim 1, wherein when the filtering target pixel is a left upper prediction pixel positioned at a leftmost upper side of the prediction block,
the filtering is performed on the filtering target pixel by applying a 3-tap filter based on the filtering target pixel, an upper reference pixel adjacent to an upper portion of the filtering target pixel, and a left reference pixel adjacent to a left of the filtering target pixel,
the upper reference pixel and the left reference pixel being reconstructed reference pixels each adjacent to the current block, and
in the 3-tap filter, a filter coefficient allocated to a filter tap corresponding to the filtering target pixel being 2/4, a filter coefficient allocated to a filter tap corresponding to the upper reference pixel being ¼, and a filter coefficient allocated to a filter tap corresponding to the left reference pixel being ¼.

### Claim 3 (depends on 1)

The video encoding apparatus of claim 1, wherein the filtering is performed when the current block is a luma component block, and the filtering is not performed when the current block is a chroma component block.

### Claim 4 (depends on 1)

The video encoding apparatus of claim 1, wherein the filtering is performed when the current block has a size of smaller than 32×32.

### Claim 5 (depends on 1)

The video encoding apparatus of claim 1, wherein the filtering is performed based on a predetermined fixed filter shape, a filter tap and a plurality of filter coefficients regardless of a size of the current block.