APPARATUS AND METHOD FOR DETERMINING 4X4 INTRA LUMINANCE PREDICTION MODE

A method and apparatus for determining a prediction mode used for video encoding/decoding are provided. The prediction mode determination method includes: (a) grouping a plurality of predetermined prediction modes into a predetermined number of groups; (b) selecting one prediction mode for each of the groups, respectively, performing predictions for a predetermined block in the selected prediction modes, and calculating prediction errors in the selected prediction modes; and (c) performing predictions for the predetermined block in other prediction modes belonging to a group including a prediction mode with a smallest prediction error among the calculated prediction errors, calculating prediction errors in the other prediction modes, and deciding a prediction mode according to the calculated prediction errors. Therefore, it is possible to select an optimal prediction mode through lower calculation times, thereby preventing an encoder from being complicated.