1. An image processing apparatus comprising: an obtaining unit configured to obtain a brightness component and a color variance component of image data; and a determination unit configured to determine whether the image data is nightscape image data or underexposed image data, using at least the brightness component and the color variance component obtained by the obtaining unit; wherein the determination unit compares the brightness component and the color variance component obtained by the obtaining unit with a plurality of predetermined brightness components and predetermined color variance components and makes a determination based on a result of the comparison.