An image processing apparatus executes a distortion correction on coordinates of a target pixel in a virtual viewpoint image based on distortion characteristics of a virtual camera and calculates coordinates in the virtual viewpoint image after the distortion correction. The image process apparatus calculates ideal coordinates in a captured image from the coordinates in the virtual viewpoint image after the distortion correction and calculates real coordinates in the captured image from the ideal coordinates in the captured image based on distortion characteristics of an imaging unit. The image process apparatus calculates a pixel value corresponding to the real coordinates from image data of the virtual viewpoint image and corrects the pixel value corresponding to the real coordinates based on ambient light amount decrease characteristics of the imaging unit and ambient light amount decrease characteristics of the virtual camera.