A first imaging unit detects far-infrared rays and captures a first image. A second imaging unit detects light having a wavelength range shorter than a wavelength range of the far-infrared rays and captures a second image. An unevenness correction unit performs unevenness correction processing on the first image. A correction data acquisition unit acquires correction data for correcting unevenness. A light irradiation determination unit determines whether or not the second imaging unit is irradiated with light having a wavelength range captured by the second imaging unit. A control unit causes the correction data acquisition unit to acquire the correction data in a case where the light irradiation determination unit determines that light irradiation is not performed on the second imaging unit.