X-ray imaging apparatus, control method for the same, and X-ray detector

Disclosed herein are an X-ray imaging apparatus for photographing a marker provided in an X-ray detector with a camera to acquire information about the distance between the X-ray detector and an X-ray source or information about the pose of the X-ray detector at low cost The X-ray imaging apparatus may include an X-ray source that generates X-rays and irradiates the X-rays. A photographing device installed in the X-ray source photographs a marker image. A controller outputs, when a marker of a plurality of markers constituting a multi-marker array formed in a surface of an X-ray detector is not detected from the marker image, a notice informing that no marker is detected. The controller detects a single marker from another marker image photographed after the notice informing that the marker is not detected is outputted.