1. An object information acquiring apparatus generating image data inside an object on the basis of an acoustic wave propagating inside the object, the object information acquiring apparatus comprising: an acoustic detector configured to receive the acoustic wave; an object information distribution processor configured to generate an object information distribution representing a property of inside of the object by using the acoustic wave; a reliability distribution generator configured to generate a reliability distribution by using the object information distribution; a similarity distribution generator configured to generate a similarity distribution between template data indicating a relation between a real image and an artifact in the image data, and the object information distribution; and a combination processor configured to perform combination processing of the reliability distribution and the similarity distribution.