Abstract: An image display device has an image output unit for displaying an overall image represented by an image signal, a region designation unit for designating a particular region within the overall image, the region designation unit including a position signal extraction unit for extracting a position signal from a predetermined signal on which the position signal is superimposed and received by the image display device, and a region decision unit for deciding the particular region on a basis of the position signal, and a control unit for selectively controlling an image quality of an image for the particular region.