1. An image processing device comprising: an image acquisition unit configured to acquire a plurality of images captured by a camera array image capturing device having a plurality of image capturing units, which have shutter speeds that are different from one another; an overlap region calculation unit configured to calculate an overlap region in which field angles overlap in the plurality of image capturing units from the acquired plurality of images; a blurred image detection unit configured to detect an image including a blur using a region image of the plurality of images corresponding to the overlap region calculated by the overlap region calculation unit; and an output image selection unit configured to select, from the acquired plurality of images, an image which is not detected as an image including a blur, as an output image, wherein, when there is a plurality of images not detected as the image including a blur, the output image selection unit selects the image captured by the image capturing unit with the slowest shutter speed as the output image.