According to some embodiments, an image processor of an embodiment has an imaging parameter acquirer and a virtual perspective image generator. The imaging parameter acquirer acquires an imaging parameter which is used by a radiographic imaging apparatus in capturing a perspective image of a target. The virtual perspective image generator determines a method of generating a virtual perspective image from volume data acquired by capturing the target in accordance with the imaging parameter. The virtual perspective image generator generates the virtual perspective image from the volume data in accordance with the determined method.
