Disclosed are an image processing apparatus that can efficiently suppress the data amount of data indicating a spatial distribution and an angular distribution of light intensity and a control method of the same. The image processing apparatus obtains data indicating the spatial distribution and the angular distribution of the intensity of light beams that have passed through partial pupil areas obtained by dividing the exit pupil of an imaging optical system into a predetermined number. The image processing apparatus then reduces the bit depth or the number of tones of signals constituting the data based on the predetermined number.