An image processing apparatus (10) includes: an area extracting unit (21) that extracts a candidate area of a classification target area in which a pixel value does not correspond to a three-dimensional shape of an imaging target based on pixel values of an intraluminal image acquired by imaging the inside of a lumen or information of a change in pixel values of peripheral pixels； and an area classifying unit (22) that classifies the classification target area out of the candidate area based on the pixel values of the inside of the candidate area, a boundary portion of the candidate area, or a periphery portion of the candidate area.
