Fast wake-up in gaze tracking system

A gaze tracking system for controlling a computer device associated with a visual display, wherein the gaze tracking system tracks a gaze point on said visual display, the system comprising:

• a first sensor with a light-sensitive surface arranged to receive light from the head of a viewer, the first sensor being selectively operable at a second frame rate or a first frame rate;
• and
• a processor configured to respond to receipt, in a low power mode of the eye tracking system, of a gaze tracking activation signal by performing the following:
• causing the eye tracking system to leave the low power mode;
• capturing an overview picture of at least a portion of the head of the viewer and locating an eye region of the viewer in the overview picture, wherein the overview picture is captured as a depth map by a second sensor either alone or in combination with the first sensor;
• capturing a plurality of pictures of at least a portion of the viewer's head using said first sensor, from which data are read out at a first frame rate;
• determining a first gaze point value of said viewer based on information from said plurality of pictures;
• providing a first control signal based on said first gaze point value;
• capturing further pictures of at least a portion of the viewer's head using a smaller portion of the or a restricted region of said first sensor, from which data are read out at a second frame rate, being lower than said first frame rate;
• determining, for each further picture, a further gaze point value of said viewer on the basis of at least one of said further pictures;
• and
• providing a further control signal based on said further gaze point.

A non-transitory computer readable medium having instructions stored thereon executable by a computing device for controlling a computer device associated with a visual display, the gaze tracking system tracking a gaze point on said visual display, that when executed cause the computing device to perform operations comprising:

• leaving a low power mode of said gaze tracking system in response to a gaze tracking activation signal from input means of said computer device at said gaze tracking system;
• capturing, an overview picture of at least a portion of the head of the viewer, and locating an eye region of the viewer in the overview picture, wherein the overview picture is captured as a depth map by a second sensor either alone or in combination with the first sensor;
• capturing, at a second frame rate, a plurality of pictures of at least a portion of the viewer's head using a smaller portion or a restricted region of said first sensor;
• determining a first gaze point value of said viewer based on information from said plurality of pictures and optionally on additional information from the overview picture;
• providing a first control signal based on said first gaze point value.