Abstract: The invention relates to a device and method for image coding. A reference frame memory for storing image data of a reference frame, a search memory for storing image data of a search frame, a motion detection means for reading image data from the reference frame memory and the search memory and calculating it to detect a motion vector, and a judgement means for generating a motion vector distribution from the motion vector detected by the motion detection means on a search range of the search frame M fields or M frame (M is an integer of one or larger) apart from the reference frame and deciding a search position between images N fields or N frames (N is an integer larger than M) part based on the motion vector distribution are provided, and the motion detection means performs motion detection at the search position decided by the judgement means. The search range can be thereby enlarged without increment of the search block transfer rate when an image is coded.