In a data compressing section, an image decompressing section decompresses compression RGB data, obtained by lossy compression, to generate decompression RGB data. A second segmentation section generates a decompression segmentation signal. Further, a differential extracting section generates a differential signal that indicates a differential between the segmentation signal and the decompression segmentation signal. A second signal compressing section generates a compression differential signal. Then, this compression differential signal is outputted as storage-use segmentation signal (signal indicating segmentation information), to a data storage section, together with the compression RGB data. The compression differential signal is smaller in size than the segmentation signal. This allows for reduction of a time required for data output and reduction of a required storage space.