| 摘要 |
A method provides a fast motion search in advanced video signal coding systems based on a reference-frame prediction and a block-mode prediction so that a motion search of each block mode and each reference frame is not required. A reference frame prediction fp, spaced from the current frame by "p" number of frames, is determined by: p=min(n-1, p0+max(a,b,c,d)); wherein p0 is a pre-chosen positive integer, n is the total number of reference frames, wherein A, B, C, and D are image blocks adjacent to a searched block, and wherein the reference image blocks have been chosen from reference frames fa, fb, fc and fd. The search is conducted within frames f0 to fp, which is a subset of all the n reference frames, so that the total computational burden is significantly decreased with respect to prior art searches. The mode frequency prediction is based on the frequencies of the block modes: F0=alpha.min(FmA, FmB, FmC, FmD); wherein a is a positive parameter less than 1.0. The block-mode selection is then conducted using the mode-frequency prediction. Each mode m among all the M possible modes will be considered if Fm is greater than or equal to F0. If Fm is less than F0 then mode m will be skipped during the motion search.
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