Prediction-based directional fractional pixel motion estimation for video coding

摘要

Motion-compensated video coding that employs prediction-based directional fractional pixel motion estimation is described. The fractional pixel motion estimation uses prediction-based searching and directional searching to search for candidate sub-pixel motion vectors oriented in a certain direction. With prediction-based searching, sub-pixel motion vectors are predicted using two techniques—median prediction and up-layer prediction. The search may be terminated early if a sub-pixel motion vector with sufficiently minimum cost is found. If prediction-based searching does not produce such a sub-pixel motion vector, the directional searching examines points in the predicted direction, rather than all eight possible neighboring points, to reduce the number of search points. Because the prediction-based directional fractional pixel motion estimation does not involve examination of neighboring integer pixel points, it can be used with any integer pixel motion estimation algorithm.