Patent ID: 7176881

Claim:
A presentation system comprising: a virtual screen a display for setting the virtual screen; a pointing mark for operating a point on the virtual screen; a photographing device for photographing the pointing mark and the virtual screen; a displaying device for displaying a predetermined image or a photographed image photographed by the photographing device; and a control device, wherein the control device calculates coordinates of the pointing mark on coordinates of the virtual screen and has a pointing function for synthesizing a predetermined point image on coordinates of the image on the displaying device, which correspond to the coordinates of the pointing mark, and wherein when at least two arbitrary reference points are set on the display, the photographing section photographs the reference points, and coordinates of the virtual screen are generated by an image processing technique from a photographed image of the reference points photographed by the photographing section, so that the virtual screen is set to have a rectangular area based on the reference points.