Abstract: An object placed on an interactive display surface is detected and its position and orientation are determined in response to IR light that is reflected from an encoded marking on the object. Upon detecting the object on an interactive display surface, a software program produces a virtual entity or image visible through the object to perform a predefined function. For example, the object may appear to magnify text visible through the object, or to translate a word or phrase from one language to another, so that the translated word or phrase is visible through the object. When the object is moved, the virtual entity or image that is visible through the object may move with it, or can control the function being performed. A plurality of such objects can each display a portion of an image, and when correctly positioned, together will display the entire image, like a jigsaw puzzle.

Abstract: Compensation of the effects of uncontrolled light in an imaging system using a controlled light source. Light from the controlled light source reflected by an object and uncontrolled light are detected in a plurality of frequency ranges. Intensity of the uncontrolled light is determined based on the varying sensitivity of an image sensor to light in the different frequency ranges and known emission characteristics of the controlled light source in the frequency ranges. Once the intensity of the uncontrolled light is determined, the total light detected at each point is adjusted to reduce the effects of the uncontrolled light in the resulting imaging data produced by the imaging system.