A method for displaying information on a screen includes modifying tone values to compress the tone of a main image; projecting by a first projector the main image with compressed tones generated with a first polarization component; modifying tone values of a sub-image for correcting tones of the sub-image; generating a correction image; and projecting by a second projector the correction image with a second polarization component different from the first polarization component over the main image projected by the first projector such that the main image is buried by an overlapped projection of the main image and the correction image generated by using the sub-image and an offset value to provide the sub-image to a viewer with a naked eye and to provide the main image to another viewer with a polarizer.