| 摘要 |
A head mountable display (HMD) is provided that has an upward facing camera associated with a wide angle (such as a fisheye) lens arranged to capture images of the environment of the HMD. The HMD also includes an image comparator arranged to derive an indication of yaw of the HMD from images captured by the upward facing camera at different points in time. The image comparator may be configured to perform two or more detection techniques to detect HMD yaw, and to combine the results of the two or more detection techniques. The HMD may also include a tilt detector. Here, the image comparator may be configured to ignore one or more portions of a captured image in dependence upon a current tilt of the HMD as detected by the tilt detector. |
