| 摘要 |
PROBLEM TO BE SOLVED: To perform determination processing in a prediction direction at high speed without deteriorating prediction efficiency and to reduce processing time and power consumption even if there are a plurality of prediction directions.SOLUTION: An intra-prediction processor 1 determines an optimum prediction direction by using a character of prediction efficiency, in which prediction efficiency in a direction orthogonal to one optimum direction is remarkably low and the prediction efficiency becomes high as a direction is nearer to the one optimum direction. Specifically, a comparing section 3 of an optimum prediction direction determining section 2 calculates an evaluation value on two orthogonal directions, compares two evaluation values and specifies the direction where the evaluation value is larger. A comparing section 4 selects a direction region according to the prediction direction specified by the comparing section 3, calculates the evaluation value in a direction where the evaluation value is not calculated in two directions where correlation in the direction region is the lowest, compares the two evaluation values, specifies the direction where the evaluation value is larger, narrows down the direction by repeating such processing and determines the optimum prediction direction. |
