An image processing device includes: a calculator that calculates a gray scale histogram for each color component of an image signal; a calculator that calculates, for each color component, a maximum and a minimum of classes having a frequency greater than zero in the gray scale histogram; a determiner that generates, for each color component, a histogram having classes each having an absolute difference value between the frequencies of adjacent classes in the gray scale histogram, and compares the absolute difference values in the histograms with a value to determine, from the presence or absence of an absolute difference value exceeding the value, an image type of the image; a generator that generates a gray scale correction curve from the calculated maximum and minimum for each color component; and a corrector that performs gray scale correction on the image signal using the gray scale correction curve.