An image processing apparatus detects predetermined information from an image signal and output a detection signal indicating the detected information, stores the detection signals for a plurality of periods, calculates a first prediction value based on a predetermined number of detection signals, from a newer one to older ones excluding a latest detection signal, stored in the storage unit, calculates a coefficient based on a difference between the first prediction value and a value of the latest detection signal, calculates a second prediction value based on the coefficient and the predetermined number of detection signals, from the latest one to older ones, and generates, based on the second prediction value, a control signal for controlling a predetermined constituent member.