Back to results
US 9,426,486 B2Granted
Methods and apparatuses of encoding/decoding intra prediction mode using candidate intra prediction modes
AssigneePantech Co., Ltd.
InventorSun Young Lee
Life of this patent
Estimating the term…
Abstract
A method and an apparatus of encoding/decoding intra prediction mode using a plurality of candidate intra prediction modes are disclosed. A method of decoding an intra prediction mode can comprise deriving three candidate intra prediction modes about a current block and deriving an intra prediction mode of the current block. Therefore, by predicting an intra prediction mode of the current block based on a plurality of candidate intra prediction modes, video encoding efficiency can be improved.
Claims11
A method for decoding an intra prediction mode of a current block, comprising:
- determining whether a first intra prediction mode derived from a first neighboring block located at the left side of the current block is identical to a second intra prediction mode derived from a second neighboring block located at the upper side of the current block;
- in response to a determination that the first intra prediction mode is not identical to the second intra prediction mode, deriving a first candidate intra prediction mode from the first intra prediction mode and deriving a second candidate intra prediction mode from the second intra prediction mode and, based on priority of order among a planar mode, a DC mode, and a vertical mode, deriving a third candidate intra prediction mode different from the first candidate intra prediction mode and the second candidate intra prediction mode;
- and
- in response to a determination that the first intra prediction mode is identical to the second intra prediction mode, determining whether the first and second intra prediction modes are identical to the DC mode and, in response to determining that the first and second intra prediction modes are identical to the DC mode, setting the first candidate intra prediction mode equal to the planar mode, setting the second candidate intra prediction mode equal to the DC mode, and setting the third candidate intra prediction mode equal to the vertical mode,
- wherein three candidate intra prediction modes are arranged according to an order of the first candidate intra prediction mode, the second candidate intra prediction mode, and the third candidate intra prediction mode.
2 more elements
An image decoding apparatus, comprising:
- an entropy decoding unit configured to decode information indicating whether one candidate intra prediction mode from among a first candidate intra prediction mode, a second candidate intra prediction mode, and a third candidate intra prediction mode is identical to an intra prediction mode of a current block, the first, second, and third candidate intra prediction modes being three candidate intra prediction modes for the current block;
- and
- a predictor configured to derive the intra prediction mode of the current block based on the information, wherein,
- if a first intra prediction mode derived from a first neighboring block located at the left side of the current block is not identical to a second intra prediction mode derived from a second neighboring block located at the upper side of the current block, the predictor is configured to derive the first candidate intra prediction mode from the first intra prediction mode, to derive the second candidate intra prediction mode from the second intra prediction mode, and to derive, based on priority of order of a planar mode, a DC mode, and a vertical mode, the third candidate intra prediction mode different from the first candidate intra prediction mode and the second candidate intra prediction mode,
- wherein, if the first intra prediction mode derived from the first neighboring block located at the left side of the current block is identical to the second intra prediction mode derived from the second neighboring block located at the upper side of the current block, the predictor, in response to determining that the first and second intra prediction modes are identical to the DC mode, is configured to set the first candidate intra prediction mode equal to the planar mode, to set the second candidate intra prediction mode equal to the DC mode, and to set the third candidate intra prediction mode equal to the vertical mode, and
- wherein three candidate intra prediction modes are arranged according to an order of the first candidate intra prediction mode, the second candidate intra prediction mode, and the third candidate intra prediction mode.
3 more elements
Dependencies are inferred from the claim text.