An image file processing method adopted in an image file processing apparatus, includes steps for: inputting from the outside an image file containing at least color information corresponding to each of pixels defined by a color space used in the image file, a color space identification tag indicating whether or not the color space used in the image file is a first color space and a color space information tag providing color space information related to the color space used in the image file; making a decision as to whether or not the color space used in the image file is the first color space based upon the color space identification tag; and referencing the color space information tag in the image file if the color space used in the image file is determined not to be in the first color space.