An image processing apparatus has a light source luminance calculating
unit which calculates the luminances of the light sources of the
plurality of colors of a back light based on an input image, a light
source maximum value detecting unit which detects a light source maximum
value that is the largest value in the light source luminances of the
plurality of colors, a light source luminance correcting unit which
corrects the light source luminances to obtain corrected light source
luminances so as to reduce the difference among the light source
luminances of the plurality of colors if the light source maximum value
is smaller than a threshold value, a gradation conversion function
calculating unit which calculates a gradation conversion function applied
to the input image corresponding to each of the plurality of colors, by
using the corrected light source luminance, and a control unit which
converts the input image by using the gradation conversion function and
outputs the input image to a liquid crystal panel and generates the
luminance control signal by using the corrected light source luminance
and outputs the luminance control signal to the back light.