A detection result of an object useful to an application can be obtained. A designated condition determining unit designates a condition of a region (improper region) which is not used as a detection result of a main object on the basis of application information which was input. An improper region identifying unit identifies an improper region on the basis of the improper region condition which was input. A final region identifying unit identifies a final main object region from a salient main object candidate region output from a candidate region identifying unit and the improper region output from the improper region identifying unit.