An example method of illuminating an optical fingerprint sensor integrated with a display, where the display includes a fingerprint (FP) pixel region and an outer pixel region exclusive of the FP pixel region, is described. The method includes: processing image data in display driver circuitry configured to drive the display to present an image; adjusting a first brightness setting, during the processing of the image data, corresponding to both the FP pixel region and the outer pixel region to provide illumination for the optical fingerprint sensor; and adjusting a second brightness setting, during the processing of the image data, corresponding to only the outer pixel region.