According to one embodiment, an image display device has a liquid crystal panel, a backlight, an intensity setting unit, a presumption unit, a signal correction unit, an error calculation unit and a control unit. The intensity setting unit sets intensities of the light sources, respectively. The presumption unit presumes color information based on intensity information representing the intensities. The signal correction unit corrects an input video signal according to the color information, and obtains a corrected video signal. The error calculation unit presumes a display image from the corrected video signal and the input video signal, and calculates display errors between the presumed display image and an input image corresponding to the input video signal. The control unit controls sets the intensities of the light sources as the emission intensities of the backlight so that the display errors obtained from the error calculation unit can be minimum.