The image processing apparatus includes: a sectional image acquisition unit that acquires a plurality of sectional images in a plurality of sectional directions of a test subject； a primary classification unit that performs a primary classification process of specifying, with respect to each of the plurality of sectional images, the type of a tissue or a lesion to which each pixel of each sectional image belongs； a secondary classification unit that performs a secondary classification process of evaluating results of the primary classification process with respect to each of the plurality of sectional images, with respect to a pixel that is common to the plurality of sectional images, to re-specify the type of a tissue or a lesion to which the pixel that is common to the plurality of sectional images belongs； and a correction unit that corrects a result of the secondary classification process on the basis of an anatomic feature of the tissue or the lesion, or an image feature value thereof.
