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.

Abstract: A method of generating a sequence of display frames, for display on a display device, derived from a data string is described. The data string is encoded to include error correction in order to enable recreation of the data string at a receiving device. The method comprises the steps of dividing the data string to be encoded into a plurality of source segments, and encoding the plurality of source segments to generate a plurality of codewords, each codeword comprising a plurality of codeword bits, and codeword bits are positioned in the sequence of frames.