A flicker detection region in which an image signal has values relating to luminance and colors within predetermined ranges is extracted from a plurality of flicker detection regions allocated in the vertical and horizontal directions of an image. A flicker component is detected using the luminance information of the image signal in the extracted flicker detection region. A correction value to correct the flicker component is generated from the detected flicker component. This makes it possible to accurately correct, using a simple arrangement, a flicker component contained in an image sensed under a light source whose brightness periodically changes even when the object or the image sensing apparatus moves.