An image processing apparatus includes a histogram calculation unit configured to calculate a histogram of a luminance value for each spatial block obtained by dividing an input image in a spatial direction, a gray scale correction coefficient calculation unit configured to calculate a gray scale correction coefficient used for correction of the gray scale of a luminance value for each bin of the histogram, and a gray scale correction unit configured to perform gray scale correction of a luminance value of a target pixel based on the gray scale correction coefficient of the bin to which the target pixel of the input image belongs and the gray scale correction coefficient of a bin adjacent to the bin to which the target pixel belongs in the spatial direction and a luminance direction.