1. An apparatus to code an image, the apparatus comprising: a low resolution image coding unit that codes a plurality of low resolution images respectively corresponding to a plurality of input images using motion estimation and compensation; and a residual image coding unit that performs intra mode coding with respect to a plurality of residual images, the residual images relating to differences between reconstructed images of the coded low resolution images that are up-sampled and the input images, the residual image coding unit performing the intra mode coding by considering a temporal correlation between neighboring ones of the residual images when the residual image being coded is between key frames, wherein the residual image coding unit comprises: a first residual coding unit that performs the intra mode coding, the intra mode coded residual image corresponding to a first key frame; and a second residual coding unit, the residual image coded by the second residual coding unit being a power distribution frame between the first key frame and a second key frame, the second residual coding unit considering a temporal correlation between the first key frame and the second key frame.