A frame sequence of moving picture data is divided into a tile image sequence, and the color space of the tile image sequence is converted to generate a YCbCr image sequence. Each frame is reduced to ½ time in the vertical and horizontal directions, and a compression process is carried out to generate compression data of a reference image. The compression data of the reference image is decoded and decompressed similarly as upon image display to restore a YCbCr image as the reference image, and a difference image sequence is generated from the reference image and the original YCbCr image. Then, compression data of a difference image is generated, and compression data obtained by connecting the compression data of the reference image and the compression data of the difference image is generated for every four frames of a tile image.