To accurately classify a form without using form layout information, the image processing apparatus utilizes a classifier that accepts a filled-in form whose image has been reduced into a specific size as an input and specifies the form type of the filled-in form. Machine learning has been performed to the classifier by a form type learning system and the form type learning system reduces an image of a filled-in form as an original document image, adds a noise to the original document image, which has not been reduced or has been reduced, to generate multiple images for machine learning, associates the form type of the original document image with the multiple images for machine learning as a label, and performs machine learning of the classifier using the multiple images for machine learning and the label as training data.