An image processing apparatus for applying a color balance correction to input image data, comprises a first highlight color calculation unit which estimates a light source at the time of shooting from pixel values of the image data, converts color values of the image data based on a condition of the estimated light source at the time of shooting, and calculates a first highlight color; a second highlight color calculation unit which calculates a second highlight color from the image data; a third highlight color calculation unit which calculates a third highlight color based on a positional relationship between the first highlight color and the second highlight color on a color space; and a correction unit which attains the color balance correction by converting the pixel values of the image data using the third highlight color.