Provided are fast motion estimation based on adaptive search range and partial matching error. A block dividing unit divides an original block which is set in a first image frame among successive image frames and candidate blocks into a plurality of operation units comprising the same number of pixels, respectively. A matching error calculating unit calculates a partial matching error. A matching error comparing unit replaces an optimal candidate block with a selected candidate block, when a total sum of partial matching errors calculated on all operation units of the candidate block is less than a minimum matching error being the total sum of partial matching errors calculated on all operation units of the optimal candidate block, and a maximum value of the partial matching errors calculated on all the operation units of the selected candidate block is less than a maximum matching error being a maximum value of the partial matching errors calculated on all the operation units of the optimal candidate block.