Abstract: A method includes extracting a first vector used to code a specific block belonging to a coded field picture arranged chronologically adjacent to a field picture to be coded and to a block to be coded, generating a second vector by scaling the first vector based on a temporal distance between the field picture and a second picture specified by a reference index and referenced for the block and included in the field picture and a temporal distance between a first picture pointed by the first vector and the coded field picture arranged chronologically adjacent to the field picture, and correcting the second vector based on a parity of the field picture, a parity of the first picture, a parity of the second picture and a parity of the coded field picture and forming the corrected second vector.