1. A method of generating an image, the method comprising: inverting values of a pixel characteristic to establish inverted values of the pixel characteristic for a number of first samples; upsampling the inverted values of the pixel characteristic to determine upsampled values of the pixel characteristic; and scaling pixel data for a number of second samples by the upsampled values of the pixel characteristic to control a modulator to generate an image, wherein the number of first samples is fewer than the number of second samples.