The invention provides methods for global motion estimation, determining a
coarse estimation, and refining a coarse estimation. Embodiments of the
invention provide a fast and robust global motion estimation algorithm
based on two-stage coarse-to-fine refinement strategy, which is capable
of measuring large motions. An embodiment of the invention may be applied
as a modification of any standard, e.g. MPEG-4 that uses the affine model
of motion estimation. Embodiments of the invention may be used in the six
parameter affine motion model, and other embodiments of the invention are
applicable to the two parameter translation model, the four parameter RST
model, and the eight parameter projective model. In a preferred
embodiment, a coarse estimation is developed in a translation invariant
domain, and then is refined in the spatial domain.