1. An image-processing system, comprising: an imaging processor that obtains a captured image; and a correction processor that produces a corrected image by correcting an aberration that emerges in the captured image; the correction processor performing processes of: producing at least two processed images by applying different processes to the captured image; producing a masking image by applying a predetermined process to a single image of either the captured image or one of the at least two processed images; producing a composite image by synthesizing the masking image and an other one of either the captured image or one of the at least two processed images, which is not used in producing the masking image, each of the images synthesized in producing the composite image originating from a single image; and producing the corrected image by synthesizing the composite image and the captured image.