1. An image processing apparatus, comprising: an image processing unit configured to execute signal processing for an output signal of an imaging element, the image processing unit comprising: a parallax detecting unit configured to apply two different viewing point images obtained from the imaging element, and to generate parallax information, wherein the parallax detecting unit is further configured such that the two different viewing point images are obtained from output signals from pixels forming the imaging element corresponding to a microlens arrangement region; and an image correcting unit configured to execute correction processing for a central viewing point image from the imaging element and to generate a two-dimensional image, and wherein the image correcting unit is further configured such that the central viewing point image is obtained from output signals from pixels forming the imaging element corresponding to a microlens non-setting region.