A touch system (10, 150, 250) includes a touch surface (60, 160, 260), an image is displayed on the touch surface, and at least one camera (66, 170, 266) acquires the image of the touch surface. The stylus contact data generator generates stylus position data in response to contact of the stylus with the touch surface. Stylus position data represents the location of the stylus on the touch surface where the stylus makes contact. The processor (56, 156, 256) is in communication with at least one camera and stylus contact data generator. The processor automatically calibrates the coordinate system of the touch system using known points in the displayed image and uses the calibrated stylus position data to update the image data used to render the displayed image on the touch surface. In one embodiment, the touch system includes an active touch-sensitive screen (252). In additional embodiments, the stylus contact data generator uses the image data generated by a pair of cameras (66) with overlapping fields of view to generate the touch when the stylus is captured in an image captured by the pair of cameras (66). Pen position data.