To reduce the time for searching a similar image area to the first image area to speed up image coding, an image processing apparatus 100 includes: a range block processing section 51 to calculate a contrast value of a range block constituting an image; a domain block processing section 52 to calculate contrast values of a plurality of domain blocks; a contrast value judging section 53 to compare the contrast values of the domain blocks to the contrast value of the range block so as to specify a similar domain block candidate; and a coding processing section 54 to search the domain block similar to the range block out of the domain block candidates and to code a relation information of the searched domain block to the range block.