Keystone correction for a projector. An uncorrected graphic is displayed on a display unit utilizing pixels. The uncorrected graphic is projected from the display unit onto a projection screen to form an uncorrected image. An orientation of the uncorrected image relative to the projection screen is captured. The uncorrected graphic is transformed into a pre-distorted graphic for projection from the display unit onto the projection screen so as to form a corrected image with an orientation more aligned with the projection screen than the orientation of the uncorrected image and such that the pre-distorted graphic utilizes more pixels in the display unit than a second pre-distorted graphic, wherein if formed, would be formed by transforming the uncorrected graphic such that the second pre-distorted graphic forms a second corrected image with a maximum rectangular area inside the uncorrected image when projected from the display unit onto the projection screen.