A method for geometrically calibrating a plurality of projectors comprising the steps of: displaying, via a first projector, a first projected image on a screen ; displaying, via a second projector, a second projected image on the screen, thereby defining an overlap region whereby the first projected image and the second projected image overlap on the screen; selecting in the first projected image a first plurality of locations in the overlap region, the first plurality of locations comprising four or fewer locations; selecting in the second projected image a second plurality of locations in the overlap region, the second plurality of locations being selected such that each of the first plurality of locations displayed on the screen overlaps with and corresponds to a respective one of the second plurality of locations displayed on the screen, the second plurality of locations comprising four or fewer locations; determining a first mapping from the first projector to the second projector using the selected first plurality of four or fewer locations displayed on the screen and the overlapping and corresponding selected second plurality of four or fewer locations displayed on the screen, thereby defining a common coordinate system among the first projector and the second projector; selecting in the first or the second projected images a third plurality of locations corresponding to boundary points of the screen; determining a second mapping from the common coordinate system to the screen using the selected third plurality of locations; and displaying, via both the first projector and the second projector, an image on the screen based upon the first mapping and the second mapping. displaying, via a first projector, a first projected image on a screen ; displaying, via a second projector, a second projected image on the screen, thereby defining an overlap region whereby the first projected image and the second projected image overlap on the screen; selecting in the first projected image a first plurality of locations in the overlap region, the first plurality of locations comprising four or fewer locations; selecting in the second projected image a second plurality of locations in the overlap region, the second plurality of locations being selected such that each of the first plurality of locations displayed on the screen overlaps with and corresponds to a respective one of the second plurality of locations displayed on the screen, the second plurality of locations comprising four or fewer locations; determining a first mapping from the first projector to the second projector using the selected first plurality of four or fewer locations displayed on the screen and the overlapping and corresponding selected second plurality of four or fewer locations displayed on the screen, thereby defining a common coordinate system among the first projector and the second projector; selecting in the first or the second projected images a third plurality of locations corresponding to boundary points of the screen; determining a second mapping from the common coordinate system to the screen using the selected third plurality of locations; and displaying, via both the first projector and the second projector, an image on the screen based upon the first mapping and the second mapping. <EOS>