1. A method comprising: identifying input values associated with an image projected by a projection system on a projection surface, the input values including a rotation angle of the projection system, one or more center-points located on edges of a distorted image projection, and a plurality of corners within the distorted image projection, the corners corresponding to an undistorted projection of the image; a keystone driver determining a vertical scaling value VerticalScaler, a vertical increment value VerticalScalingIncrement, a horizontal scaling value HorizontalScaler, and a horizontal increment value HorizontalScalingIncrement based on the input values, wherein the determining comprises applying the following first and second equations: InputHeight = VerticalScaler + OutputHeight ⁡ ( OutputHeight - 1 ) 2 × VerticalScalingIncrement ; ⁢ and InputCenter = OutputCenter ⁢ × VerticalScaler + OutputCenter ⁡ ( OutputCenter - 1 ) 2 × VerticalScalingIncrement , wherein InputHeight comprises a height of the distorted image projection, InputCenter comprises a distance to the center of an edge of the distorted image projection, OutputHeight comprises a height of the undistorted projection of the image, and OutputCenter comprises a distance to the center of an edge of the undistorted projection of the image; and a keystone corrector predistorting the image responsive to the determining and based on the determined vertical scaling value, vertical increment value, horizontal scaling value, and horizontal increment value, the predistorted image exhibiting no distortion and aligning with the plurality of corners when projected on the projection surface.