An image processing apparatus comprises: an image transformation section which generates, from print data, image data of character or line drawing of gradation value n1 and image data of a photographic image of gradation value n2 (n2>n1); an encoding section which encodes the image data of the character or the line drawing of the gradation value n1, and generates the encoded image data of the character or the line drawing of the gradation value n2; an attribute adding section which generates attribute data indicating an attribute of each of images with respect to the encoded image data of the character or the line drawing of the gradation value n2 and the generated image data of the photographic image of the gradation value n2, and adds the attribute data to each of the encoded image data of the character or the line drawing and the generated image data of the photographic image; and a synthesizing section which synthesizes the encoded image data of the character or the line drawing to which the attribute data is added and the generated image data of the photographic image to which the attribute data is added, and outputs the synthesized data.