A display device comprises a display panel comprising high brightness subpixel repeating groups--for example, RGBW display panels. Displays comprise subpixel repeating groups that include first and second primary color stripes and third and fourth primary color subpixels that are disposed on a checkerboard pattern. A subpixel rendering operation includes, or is followed by, a white subpixel adjustment operation that adjusts the brightness of the white subpixels in the areas of the displayed image that contain high spatial frequency features such as lines and text, in order to improve image quality such as image contrast.