Patent ID: 8907889

Claim:
A method, comprising: detecting an image of one or more images of respective one or more spatially fixed markers adapted for placing in fixed locations within view of a pixelated sensor, said markers emitting radiation having a predetermined frequency band, said image appearing on the pixelated sensor within a handheld device; filtering at said handheld device radiation so as to pass the radiation in the predetermined frequency band and to substantially exclude other radiation; generating separate image data for each of the one or more markers within the image; processing the image data in the handheld device to provide separate processed image data for each of the markers within the image appearing on the pixelated sensor; wherein the processed image data comprises coordinate data of each of the one or more markers within the image, 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; and sending from said handheld device to electronic equipment circuitry the processed image data from which a location of an on-screen icon is actively controlled.