Abstract: A controller (442) for a video processing system (400). The controller (442) is configured to receive acquired images; recognise a looking-stimulus by determining that an acquired image shows a user to be looking towards the camera or a display screen; and/or recognise a present-stimulus by determining that a user is visible in an acquired image an acquired image shows a user that is not looking towards the camera or the display screen. The controller (442) can then generate a video stream based on the acquired images, and set a characteristic of the video stream based on the recognised looking-stimulus or the present-stimulus.

Abstract: Waking a computing device from a stand-by mode may include determining a wake zone relative to a display device and, when the computing device is in stand-by mode, detecting a gaze point relative to the display device. In response to determining that the gaze point is within the wake zone, a wake command is generated and passed to a program module, such as the operating system, to cause the program module to wake the computing device from the stand-by mode. When the computing device is not in stand-by mode, another gaze point may be detected and, in response to determining that the other gaze point is within the vicinity of a selectable stand-by icon, the stand-by command is generated and passed to the program module to cause the program module to place the computing device into the stand-by mode.