A display driver adapted to drive a display panel is provided. The display panel includes a pixel column direction and a pixel row direction. The display driver includes an image data processor unit. The image data processor unit performs a two-dimensional subpixel rendering operation on an input image data to generate an output image data. The display driver drives the display panel according to the output image data. The two-dimensional subpixel rendering operation includes a first one-dimensional subpixel rendering operation in a first direction and a second one-dimensional subpixel rendering operation in a second direction. The first direction is one of the pixel column direction and the pixel row direction, and the second direction is another one of the pixel column direction and the pixel row direction.