Patent ID: 8743289

Claim:
An image display apparatus, comprising: a picture display unit that forms and displays an optical image based on a video signal; a gamma adjustment image display unit that displays a gamma adjustment image containing input/output characteristics of a signal level of the video signal in the displayed optical image; an adjustment operation unit that changes the displayed input/output characteristics on the image; and an input/output characteristics setting unit that sets input/output characteristics of the signal level of the video signal in accordance with the input/output characteristics changed on the image, wherein input levels of a plurality of adjustment points are preset to fixed reference values, and the adjustment operation unit includes a point selecting part that selects one of the adjustment points desired to be changed in the input/output characteristics displayed in the image and a level changing part that is capable of changing both of the input level and an output level of the selected adjustment point, in which the input level can be changed from one of the fixed reference values to an intermediate value between the selected fixed reference value and a fixed reference value adjacent to the selected fixed reference value.