RF-ENCODING METHOD FOR IMAGE ENCODED DATA AND PROGRAM RECORDING MEDIUM THEREFOR

摘要

PROBLEM TO BE SOLVED: To improve the reduction efficiency of an encoded data amount while suppressing image degradation and a generation operation amount in the case of efficiently re-encoding intra-frames in image encoded data encoded at a certain bit rate. SOLUTION: From the intra-frame included in source encoded data and the frames before and after that, a bidirectional encoding frame and a forward direction encoding frame are detected as reference frames (S1). The motion vectors of the small block unit of the reference frame are extracted (S2), and by using the extracted motion vectors, the motion vectors for re-encoding are calculated by switching a calculation processing corresponding to the encoding mode of the respective small blocks of the bidirectional encoding frame (S3-S9). The motion vectors corresponding to the respective small blocks of the intra- frame are calculated by using the motion vectors (S10) and the intra-frame is re-encoded as the forward direction encoding frame by using the calculated motion vectors (S11).