To provide an image processing apparatus capable of correcting an orientation of a scanned image, even if the orientation of a document during scanning is incorrect. An image processing apparatus includes a document type determination unit configured to determine a document type of image data obtained by optical reading, a selection unit configured to select, based on a determination result from the document type determination unit, a determination algorithm to be applied, from a plurality of determination algorithms for determining an orientation of an image, and an orientation determination unit configured to determine an orientation of an image in the image data by using the determination algorithm selected by the selection unit.