1. An image processing apparatus comprising: a first feature value calculating section calculating, in an arbitrary region of an image obtained by picking up an image of a subject, a first feature value for each of pixels constituting the arbitrary region; a region dividing section dividing the arbitrary region into multiple regions on the basis of the first feature values; a second feature value calculating section calculating a second feature value for each region of the multiple regions divided by the region dividing section; a classification section classifying each region of the multiple regions divided by the region dividing section into any of multiple kinds of attributes on the basis of the second feature value; a diagnostic support information calculating section calculating an attribute value based on an area or a number, for each attribute of a same kind among the multiple kinds of attributes classified by the classification section; a judgment section judging whether a region having a predetermined attribute exists or not among the multiple regions divided by the region dividing section; and a correction section correcting, when it is judged by the judgment section that the region having the predetermined attribute exists, the attribute value for the region classified into the predetermined attribute on the basis of attribute values calculated for attributes other than the predetermined attribute, wherein the diagnostic support information calculating section calculates diagnostic support information for supporting a diagnosis for the arbitrary region on the basis of the attribute value corrected by the correction section for the region having the predetermined attribute and the attribute values calculated by the diagnostic support information calculation section for the multiple regions other than the region having the predetermined attribute.