Image processing apparatus, image processing method, and image pickup apparatus for displaying image for use in focusing operation

Abstract

An apparatus which is capable of displaying an image for a user to easily recognize the brightness and colors of an area of interest in the image and easily determine whether a subject is in focus. The amount of image shift between parallax image signals is calculated. The amount of blur in an area where an image shift occurs in the parallax image signals is determined based on the amount of image shift. A blurring process is performed on at least one of the parallax image signals based on the amount of blur. An image based on the display image signal generated based on the resulting parallax image signal is displayed on a display. The determined amount of blur is greater than the amount of blur shown by a subject image defocused by the amount of defocus converted from the amount of image shift.