In general, a color image display device expresses various colors by mixing three colors of R (red), G (green), and B (blue). For example, each pixel of a display panel is provided with R, G, and B color filters, and light from a backlight is transmitted by these color filters so that light of R, G, and B is emitted.
Recently, there is known a technique in which each pixel is provided with a W (white) subpixel in addition to R, G, and B subpixels. In this case, image data acquired by a color image display device is normally in the form of RGB data, and accordingly it is necessary to convert the image data into data corresponding to a pixel of RGBW.
For example, Patent Literatures 1 and 2 describe a method in which a liquid crystal display device having RGBW pixel sequences converts RGB data into RGBW data.