Patent ID: 7864159

Claim:
A method, comprising: emitting non-visible radiation having a predetermined frequency band from two or more markers adapted for placing in spaced-apart fixed locations on or proximate to a display,; filtering at a handheld device radiation so as to pass the radiation in the predetermined frequency band and to substantially exclude other radiation; passing the radiation in the predetermined frequency band through an imaging element to a pixelated sensor; producing separate images of at least two of the spaced-apart markers when radiation therefrom is incident on the pixelated sensor within the handheld device; generating image data for each of the at least two separate images; processing the image data in the handheld device to provide coordinate data of the images appearing on the pixelated sensor, the coordinate data comprising less data than the image data, wherein processing the image data further comprises: determining an intensity value for each of a plurality of pixels of the pixelated sensor, the intensity value attaining one of three or more quantized intensity values; identifying a set of pixels which have an intensity value above a specified threshold; and generating the coordinate data based on the intensity value and the location of each of the pixels in the set of pixels; sending from said handheld device the coordinate data derived from the processing of the image data; and, triggering an action to be taken by electronic equipment circuitry in response to the coordinate data and the handheld device's sending of a signal to indicate that the action is desired, wherein the action includes actively controlling movement of a cursor displayed on the display, the cursor comprising a graphical element usable for selecting one or more other graphical elements from within a graphical user interface generated by the electronic equipment on the display.