1. A controller for enhancing lower-dynamic range (LDR) image data representing an image, the controller configured to: identify at least one enhancement region within the image; apply a brightness enhancement function to the LDR image data to generate higher-dynamic range (HDR) image data, wherein compared to the LDR image data, the HDR image data comprises increased luminance values of enhancement-region pixels in the enhancement region and increased luminance values of one or more boundary-region pixels outside of the enhancement region, the luminance value increase of the boundary-region pixels decreasing with distance from the enhancement region.