Patent ID: 8391362

Claim:
A motion vector estimation apparatus which selects, from among a predetermined number of n candidate block sizes where n is an integer of 2 or greater, a block size to be used for coding a current block to be coded in a current picture to be coded, and estimates a motion vector of the current block using the selected block size, said apparatus comprising: an obtaining unit operable to obtain a motion amount indicating an amount of motion of the current block in a reference picture; a block size narrowing-down unit operable to narrow down the n candidate block sizes for use in estimating a motion vector to m candidate block sizes in a case where the motion amount obtained by said obtaining unit is greater than a first predetermined threshold value, where m is (i) an integer greater than or equal to 1 and (ii) an integer smaller than n; and a motion vector estimation unit operable to estimate the motion vector of the current block using the m candidate block sizes to which the n candidate block sizes have been narrowed down by said block size narrowing-down unit, wherein said block size narrowing-down unit narrows down the n candidate block sizes to the m candidate block sizes according to a descending order of size of the n candidate block sizes so that the m candidate block sizes include the m largest candidate block sizes from among the n candidate block sizes.