An image processing apparatus includes a print setting acquisition unit configured to acquire a print paper size, a threshold setting unit configured to set, based on the print paper size, a threshold for a protruding portion of a print product, the protruding portion protruding from a reading range, an image acquisition unit configured to acquire a scanned image of the print product, a detection unit configured to detect the protruding portion from the scanned image, and a conveyance displacement abnormality detection unit configured to detect conveyance displacement abnormality from the threshold and a result of the detection.