High-speed motion estimator and method with variable search window

摘要

A motion estimation apparatus and method capable of reducing the amount of computation required for motion estimation in the compression of moving images are provided, including a first part for decimating a reference macroblock at a decimation ratio of 4:1, decimating a search window of a predetermined size at a decimation ratio of 4:1, and estimating a first motion vector responsive to the 4:1 decimated macroblock and window, a second part responsive to the first part for decimating the reference macroblock and decimating the search window each at a decimation ratio of 2:1, and estimating at least one second motion vector responsive to the 2:1 decimated macroblock and window, and a third part responsive to the second part for performing a full search motion estimation on a block within horizontal and vertical ranges of −N₁₁ to +N₁₂ of the estimated first motion vector, estimating a third motion vector if one second motion vector was estimated, or performing full search motion estimation on a block within horizontal and vertical ranges of −N₂₁ to +N₂₂ of the estimated at least one second motion vector if two second motion vectors were estimated.