IMAGE CODING DEVICE, IMAGE DECODING DEVICE, IMAGE CODING METHOD, AND IMAGE DECODING METHOD

Disclosed is an image decoding method including a step of variable-length-decoding coded data multiplexed into a bitstream to acquire compressed data associated with a coding block, a reference image restriction flag indicating whether or not to restrict a significant reference image area which is an area on a reference image which can be used for the motion-compensated prediction, and motion information and a motion-compensated prediction step of carrying out a motion-compensated prediction process on the coding block on the basis of the motion information to generate a prediction image, in which the motion-compensated prediction step includes a step of when the prediction image includes a pixel located outside the significant reference image area, carrying out a predetermined extending process to generate the prediction image on the basis of the reference image restriction flag by using the motion information.