1. A method for predicting motion vectors, wherein said motion vectors express displacements of irregular image segments between at least one reference frame and a new image frame, said method comprising: accessing a segment list for at least one reference frame; accessing motion vectors for a plurality of segments from the list; generating a hierarchy of segments consisting of at least two levels, wherein higher levels represent sparser subsets of segments at lower levels; and using said hierarchy of segments to predict motion vectors for segments in lower levels using motion information for nearby segments in at least one higher level.