Patent ID: 8279238

Claim:
An image display device, comprising: a display part that displays a video image based on an input signal; a video image adjusting part for adjusting a parameter of the video image; a region selecting part for selecting a region in the video image, with respect to which an adjustment of the parameter is performed; and a luminance difference detecting part that detects a luminance difference between left and right portions or upper and lower portions of the selected region, wherein the display part is capable of composing, based on the video image in the selected region, a first video image before the adjustment of the parameter and a second video image to be used for the adjustment, displaying the first video image and the second video image above and below each other or side by side, and displaying one of the first video image and the second video image upside down or in a mirror-reversed manner relative to the other; and the luminance difference determines whether to display an upside-down image or to display a mirror-reversed image.