There is provided a technique for adaptively acquiring, from a tomogram of an eye region, diagnosis information data of the eye region which is used for the diagnosis of a plurality of kinds of diseases, without increasing load on a user. A layer acquisition unit (331) acquires a predetermined layer area from the tomogram of the eye region. A changing unit (332) changes an algorithm for the acquisition of diagnosis information data as information used for the diagnosis of the eye region from the tomogram based on the information data extracted from the layer area. A quantifying unit (336) acquires diagnosis information data from the tomogram based on the changed algorithm.