1. A method for adjusting a grayscale spline, defined by a set of interconnected points, each of said points having a location adjustable by a user through a user interface, for an output device comprising the steps of: a) adjusting, responsive to user input of a location adjustment through said user interface, a location of a first point previously located on said grayscale spline; b) adjusting a location of at least one other point, previously located on said grayscale spline, based on the adjusted location of the first point; c) generating a grayscale spline through said first point and said at least one other point; and d) producing an image with said output device using said generated grayscale spline.