Abstract: The target image acquisition unit 31A acquires a target image subjected to annotation of a correct answer. The first correct answer data acquisition unit 32A acquires first correct answer data indicative of a position including a target object displayed in the target image, a position of a part of the target object or a candidate position of the target object. The second correct answer data generation unit 33A generates, on a basis of an estimator, second correct answer data indicative of an estimated position of the target object from the first correct answer data. Here, the estimator is learned to output the estimated position of the target object from a position including the target object or a position indicating a part of the target object or a candidate position of the target object.