A dual-panel display system is provided that comprises control modules and algorithms to select codeword pairs (CWs) to drive a first image-generating panel and a second contrast-improving panel. The first codewords is selected by considering some characteristics of the input image data (e.g., peak luminance) and to improve some image rendering metric (e.g., reduced parallax, reduced contouring, improved level precision). The first codeword may be selected to be the minimum first codeword within a set of codeword pairs that preserves the peak luminance required by the input image data. Also, the first codeword may be selected to minimize the number of Just Noticeable Difference (JND) steps in the final image to be rendered. The second codeword may be selected to similarly improve image quality according to a given quality metric.