SIGNAL PROCESSING APPARATUS AND SIGNAL PROCESSING METHOD

Provided is a signal processing apparatus that estimates image distortion in a case where images are captured through a transmissive body allowing light to pass through. The signal processing apparatus includes a lens distortion estimation section that estimates lens distortion based on a location of a feature point in a first image and a second image of an object. The first image is captured by an imaging section through a transmissive body and a lens that allow light to pass through. The second image is free of transmissive body distortion caused by the transmissive body and free of the lens distortion caused by the lens. The apparatus further includes a transmissive body distortion estimation section that estimates the transmissive body distortion based on the location of the feature point in the first image and a third image that is obtained by removing the estimated lens distortion from the first image.