1. An image processing apparatus for storing an image of an original and outputting an entire area or partial area of the stored image of the original as a color image or a monochrome image, the apparatus comprising: an area setting unit for setting a plurality of areas; a color determination unit for determining whether the original is in color or monochrome in each of the areas set by the area setting unit on the basis of the image of the original; and a unit for storing a result of determination made by the color determination unit on the image of the original as accessory information on the image of the original, wherein the color determination unit includes a block color determination processing unit for dividing the image of the original into a plurality of first blocks and determining whether or not each of the first blocks is a color image area, and an area color determination processing unit for determining whether the original is in color or monochrome in each of the areas set by the area setting unit on the basis of a result of determination made by the block color determination processing unit on the first blocks included in the area.