Patent ID: 7773674

Claim:
An image matching method for performing an image matching by using an iterative gradient method which iteratively estimates at least one of motion or parallax of a video on a block-by-block basis based on an initial displacement vector, comprising: calculating a motion vector for a block in a video frame using the iterative gradient method, the block having a first block size; dividing the block into a plurality of small blocks, each of the small blocks having a block size smaller than the first block size; determining an initial displacement vector for each of the small blocks with an initial displacement vector determination section, the initial displacement vector being determined by selecting an optimum motion vector from among motion vector candidates including motion vectors of blocks neighboring the block having the first block size and a motion vector of a block in a previous video frame corresponding to the block having the first block size; and calculating respective motion vectors for each of the small blocks by performing the iterative gradient method, based on the initial displacement vectors, on each of the small blocks to calculate the motion or parallax for each of the small blocks.