Patent ID: 8217997

Claim:
A method of interactively and remotely operating a computer system, comprising: generating visual payload image frame data; combining, with the visual payload image frame data, at least one positioning target pattern corresponding to complementary intensity variances at one or more selected pixel locations of the visual payload image frame data, applied in successive frames; displaying the combined visual payload image frame data and positioning target pattern on a display; capturing image data representative of at least a portion of the display including the positioning target, over at least two frames; processing image data to subtract frames of the captured image data from one another to recover the positioning target pattern as viewed remotely from the display; and determining a pointed-to location of the display responsive to the recovered positioning target pattern; wherein the combining step comprises, for each pixel at which the positioning target pattern is to be displayed: determining an intensity component value for at least one color component of the visual payload image frame data at that pixel; calculating at least one variance value responsive to the intensity component value at that pixel, and according to an inverse gamma correction function; in a first frame, adding a calculated variance value to the visual payload image frame data for that pixel; and in a second frame, subtracting a calculated variance value from the visual payload image frame data for that pixel.