1. An X-ray imaging apparatus comprising: an X-ray generator to generate X-rays and irradiate an object with the X-rays; an X-ray detector to detect X-rays irradiated from the X-ray generator and transmitted through the object; and a host device to generate and display a plurality of X-ray images from the detected X-rays and to display an image containing at least one of bone image information and soft tissue image information of the displayed X-ray image, the bone image information and soft tissue image information corresponding to a region selected by a user.