An image processing unit 36 includes a frequency analysis unit 40, an optical characteristic acquisition unit 42, and a filter acquisition unit 44. The frequency analysis unit 40 acquires data in the frequency domain of each of first image data and second image data which are acquired by capturing an object image using a first optical system and a second optical system, respectively. The optical characteristic acquisition unit 42 compares the data in the frequency domain of the first image data with the data in the frequency domain of the second image data to acquire frequency characteristic data related to optical characteristics of the second optical system. The filter acquisition unit 44 acquires a sharpening filter associated with the second optical system from a plurality of sharpening filters associated with the first optical system.