Patent ID: 8300985

Claim:
An image-registration method comprising: obtaining a first image and a second image; generating first and second image pyramids based on the first and second images, respectively, by performing sub-sampling which reduces the length and width of each of the first and second images by half; and determining one of five directions respectively corresponding to (−1, 0), (1, 0), (0, 0), (0,−1), and (0, 1) as an optimal movement direction for a current level of the first and second image pyramids based on two images belonging to a corresponding level, updating a motion vector for the current level based on the optimal movement direction for the current level and updating a first image belonging to a level directly below the current level based on the updated motion vector for the current level, wherein the updating of the motion vector comprises respectively updating a motion vector for each of a plurality of levels of the first and second image pyramids in an order from an uppermost level to a lowermost level as the current level respectively increments from the uppermost level to the lowermost level.