1. An image processing apparatus which composes a plurality of images captured while changing an exposure amount, comprising: a displacement detection unit configured to detect a displacement amount between the plurality of images; a correction unit configured to correct a displacement between the images based on the displacement amount detected by said displacement detection unit; a moving object region detection unit configured to detect a moving object region from the plurality of images for which the displacement has been corrected; an image composition unit configured to compose the plurality of images for which the displacement has been corrected; and a moving object processing unit configured to replace a region corresponding to the moving object region of the composite image composed by said image composition unit by an image obtained by performing weighted addition of the plurality of images.