Abstract
A method of encoding sequence information into a sequence of display frames for display on a display device, the method comprising the steps of: generating the sequence of display frames; inserting monitor flags within each display frame, each monitor flag being capable of moving between a first state and a second state; setting the state of monitor flags within each display frame to a predetermined configuration; encoding sequence information in the sequence of display frames by varying the predetermined configuration throughout the sequence of display frames such that neighbouring display frames in the sequence have different predetermined configurations.