Motion estimation technique for digital video encoding applications

摘要

The present invention provides an improved motion estimation encoder for digital video encoding applications. In one example embodiment, the improved encoder receives a raw image in the form of a current frame and estimates the macroblock motion vector with respect to a reference frame. The encoder then performs an initial local search around an initial motion vector candidate derived from spatio-temporal neighboring macroblock parameters. The encoder then compares the user-defined complexity scalable sum of absolute difference between the original and the associated reference macroblock against an adaptive threshold value for motion estimation convergence. The encoder introduces a global full search around a candidate from a coarser level, in case an initial local search fails. The encoder then selects an inter encoding mode for coding the current macroblock, when the first local search is successful, otherwise the encoder selects the inter or intra encoding mode for encoding the current macroblock by comparing variances of the original and difference macroblocks.