In a transmissive liquid crystal display device including a liquid crystal panel and a backlight, the liquid crystal panel contains pixels each divided into four subpixels, a red (R), a green (G), a blue (B), and a white (W) subpixel. The backlight is a white backlight emitting light with controllable emission luminance. A luminance lowering section performs luminance lowering processing on input RGB signals (original input signals) for transformation into luminance-lowered RGB signals. An output signal generating section obtains transmittances and a backlight value from the luminance-lowered RGB signals.