This invention has as its object to provide an image processing apparatus, which can obviate the need for image re-input, can effectively generate encoded data that falls within a set size, and can minimize deterioration of image quality. To this end, an image processing apparatus according to this invention includes first discrimination unit for discriminating the type of image of each of a plurality of regions, which form image data input, second discrimination unit for discriminating if the image data is inputted by a continuous scan of images, selection unit for selecting an encoding method used in compression of each region on the basis of discrimination results of the first and second discrimination unit, first compression unit for compressing image data of each region using the encoding method selected by the selection unit, and second compression unit for compressing information that pertains to the type of image of each region.