1. An image processing method comprising: capturing, by a camera, an image of a head of a user of a head mountable display device; detecting, by a detector device, a position of the head mountable display device in the image captured by the camera; identifying, by a processor device, a region of the user's face that is occluded by the head mountable display device; and the processor device at least partially replacing a region of the captured image corresponding to the head mountable display device with a corresponding portion of a 3D facial model to provide a modified image.