Abstract: Image data combined of a first piece of and a second piece of image data and selection data to selectively designate one of the first piece or the second piece of image data is input to an input portion 1. Those data are expanded by an expanding portion 4. A first image-structure recognizing portion 2 (second image-structure recognizing portion 3) recognizes the image structure of the first (second) piece of image data. A first image-structure converting portion 5 (second image-structure converting portion 6) converts the recognized image structure of the first (second) piece of image data to the image structure of an output device 9. Those image data and the selection data are expanded. A combining portion 7 combines the first piece and the second piece of image data having the same image structure as of the output device while successively selecting the first piece or the second piece of image data on a basis of the selection data, and outputs the combined image data to the output device 9.