1. An image display device, comprising: a display unit that displays an image; a scene change detection unit that detects a change observed in a scene of the image; a brightness enhancement determination unit that determines a brightness enhancement level of the image based on a detection result of the scene change detection unit; and a brightness enhancement unit that subjects an image signal of the image to a brightness enhancement process in which, based on a determination result of the brightness enhancement determination unit, a brightness enhancement amount is set to 0 or a small value on a side largely observed with the change of the scene, and on a side scarcely observed with the change of the scene, the brightness enhancement amount is set to a large value.