Abstract: A projector system projects derivation markers (3010) together with a guarantee marker (3020) onto a projector screen, allows noise images as marker candidates, automatically generates a plurality of provisional two-dimensional projection conversion formulas, and uses the position of the guarantee marker (3020) to detect the true conversion formula from among the generated plurality of conversion formulas.

Abstract: In a projector system, a user specifies an arbitrary position on a projector screen (60) using laser light by means of a light pen (30). A PC (10) detects the continued specification of the same position for a prescribed amount of time on the basis of an acquired image of an optical receiver (40). After the prescribed amount of time elapses, the PC (10) generates an ON flag signal equivalent to the click button operation of a mouse.

Abstract: A pointer light tracking method wherein all black image and white square images located at four corners of the all black image are projected on the display, the display on which the all black image and the white square images are displayed is shot by a camera, a domain corresponding to the white square image is extracted from the obtained image data, central coordinates (x, y) of the extracted domain are computed, and a parameter necessary in performing distortion correction by use of projection conversion for coordinate expressing the position of the pointer light on the display is computed from the computed central coordinates (x, y) and central coordinates (X, Y) of the white square image.