Disclosed is an image processing device. The image processing device includes an input unit, and a processor which retargets an image frame input through the input unit and acquires an output image frame, wherein the processor identifies an area, in which pixel values are to be padded, on the basis of the input image frame and information about the output image frame, identifies a first pixel block on the basis of a target pixel area included in the identified area, identifies a second pixel block on the basis of pixel values included in the first pixel block, and pads the target pixel area on the basis of pixel values included in the second pixel block, so as to able to acquire the output image frame.