An apparatus and method are provided for displaying an image. A process of human color recognition and a process of human color response are analyzed to find a reference brightness value of an image such that a dark region of the image can be correctly detected. A brightness of the image is adjusted such that a specific region is not excessively bright or dark. Accordingly, a user can recognize the image. The apparatus and method can be applied to an image display device having a Liquid Crystal Display (LCD), such as a portable wireless terminal having a small-sized LCD.