Abstract: An interactive display system including a wireless pointing device, and positioning circuitry capable of determining absolute and relative positions of the display at which the pointing device is aimed. The pointing device captures images displayed by the computer, using a rolling shutter, the images including one or more human-imperceptible positioning targets. The positioning targets are presented as patterned modulation of the intensity (e.g., variation in pixel intensity) in a display frame of the visual payload, followed by the opposite modulation in a successive frame. At least two captured image frames are subtracted from one another to recover the positioning target in the captured visual data and to remove the displayed image payload. The capturing of images at the pointing device is synchronized with the release of image data to the display, to avoid errors in the positioning operation.