IMAGE CODING APPARATUS AND METHOD

• Main Authors: MASUNO TAKASHI, TASAKA HIROSHI, ARIMURA KOJI, ARAKAWA HIROSHI
• Format: Patent
• Language: English
• Published: 14.09.2006
• Subjects: BASIC ELECTRONIC CIRCUITRY; CODE CONVERSION IN GENERAL; CODING; DECODING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PROBLEM TO BE SOLVED: To accelerate a processing speed by reducing computational complexity relating to selection of an intra-prediction mode. SOLUTION: An image coding apparatus 1 does not determine the intra-frame prediction mode on the basis of the prediction error of the entire blocks included in a macro block, but executes intra-frame prediction with the predetermined intra-frame prediction mode for a certain block. A block selection unit 41 judges that the current block to be coded is a prediction error calculation block or a non-prediction error calculation block. In the case where the current block is a prediction error calculation block, a mode error value calculation unit 42 calculates the prediction error by the sum of absolute differences and the like for all of the intra-frame prediction modes, an inter-mode comparison unit 43 compares the prediction errors, and as a result of the comparison, the intra-frame prediction mode having the minimum prediction errors is determined as the intra-frame prediction mode. In the case where the current block is a non-prediction error calculation block, the prediction error is not calculated. As an alternative method, a prediction mode estimation unit 44 determines the intra-frame prediction mode on the basis of neighboring prediction mode information 48 stored in a storage unit 47. COPYRIGHT: (C)2006,JPO&NCIPI