Patent ID: 7349583

Claim:
A method for estimating global motion between a reference image or a portion thereof and a current image or a portion thereof, the method comprising steps of: computing translation invariant representations of the reference image or the portion thereof and the current image or the portion thereof, wherein the translation invariant representations preserve non-translational motion effects present in the reference image or the portion thereof and the current image or the portion thereof; from the translational invariant representations, determining a coarse estimation of the effect of the non-translational motion between the reference and the current image or the portions thereof; and determining a coarse estimation of the effect of translational motion from the coarse estimation of the effect of the non-translation motion and the current image or the portion thereof, wherein the effect of the non-translation motion and the effect of the translation motion together constitute a coarse estimate of the global motion, wherein said step of determining a coarse estimation includes a step of adaptively re-sampling the translation invariant representations of the reference image or the portion thereof and the current image or the portion thereof; wherein said step of adaptively re-sampling comprises re-sampling an original image that is one of the reference image or the portion thereof or the current image or the portion thereof: conducting no re-mapping where past motion parameters indicate small mean scaling and small mean rotation for the original image or the portion thereof; conducting polar mapping where past motion parameters indicate small mean scaling and possibly large mean rotation for the original image or the portion thereof; conducting log-log mapping where past motion parameters indicate small mean rotation and possibly large mean scaling for the original image or the portion thereof; and otherwise conducting log-polar mapping.