1. A computer method for generating a pixel display pattern from a pixel given pattern using a transform, the method comprising: (a) for at least one display attribute, determining at least one constraint on the transform; and (b) for at least one substantially uniform background luminance value and subject to the at least one constraint, determining the transform such that, if the pixel display pattern is displayed against the substantially uniform background, visual distortion as compared with the pixel given pattern is minimized.