The present invention comprises: capturing a medical image of a subject by an image-capturing unit generating compressed image data by compressing on the basis of a plurality of pixels of uncompressed image data, where the uncompressed image data is image data of the captured medical image of the subject, by an image data compression unit setting a search range of the compressed image data and also setting a search range of the uncompressed image data, by a search range setting unit and setting a region of interest for the medical image on the basis of the search range of the uncompressed image data and the search range of the compressed image data, by a region-of-interest setting unit.