1. An image display device, comprising:a light source;
a display unit that spatially modulates light from said light source on a basis of an input video signal to form an image;
a histogram acquisition unit that acquires, on the basis of said input video signal, a first histogram, in which image data is indicated by frequencies of levels of brightness, and a second histogram that has a number of levels of brightness that differs from a number of levels of brightness of said first histogram; and
a control unit that implements dimming control for adjusting a luminance of said light source on a basis of said first histogram and said second histogram,
wherein a total sum of histogram count values of said first histogram is equal to a total sum of histogram count values of said second histogram.