In an X-ray imaging apparatus (100), an image processor (5b) is configured to apply a super-resolution process to a first region (A1) in each of acquired images (Ia), the first region including a subject (S), and to increase a number of pixels according to an increase in resolution in the first region by application of the super-resolution process thereto by a simpler process than the super-resolution process with respect to a second region (A2) other than the first region in each of the acquired images.