Disclosed are an image-encoding apparatus and an image-decoding apparatus for efficiently transmitting a large capacity image. The image encoding apparatus separates an input image into pixel units to generate real images of a first region and of a second region, performs a predictive filtering process on the real image of the first region to generate a predictive image of the second region, and differentiates the predictive image of the second region from the real image of the second region to thereby efficiently reduce the volume of data prior to encoding the input image.