An image display apparatus includes an image displaying unit that includes a light source unit and a light modulation device, a histogram generating unit, a light source luminance calculator, a function storing unit, a first evaluation value calculator, a second evaluation value calculator, a third evaluation value calculator, a function acquiring unit and a control unit. The function acquiring unit acquires a plurality of the third evaluation values by repeating processing by the first to third evaluation value calculators with modification to a level conversion function and acquires a level conversion function that has a smallest third evaluation. The control unit supplies a signal of a converted video resulting from conversion of the image with the acquired level conversion function to the light modulation device.