An image display device has pixels each of which includes sub-pixels of four or more colors, and displays a high-definition image that has been subjected to sub-pixel-level filtering processing. The image display device includes a display panel in which color filters of sub-pixel colors including three principal colors of red, green, and blue as well as at least one color other than the three principal colors are arranged regularly; and an image processor that performs filtering processing with respect to an input image signal. The image processor includes: a principal color conversion section that generates sub-pixel signals corresponding to the sub-pixel colors, respectively, from the input image signals Rin, Bin, and Gin of the three principal colors; and a sub-pixel enhancement section that gives, to the sub-pixel signals, position information in accordance with an order of arrangement of the color filters of the sub-pixel colors in the display panel, and performs the filtering processing sub-pixel by sub-pixel.