1. An image processing apparatus comprising: an image acquisition unit that acquires first image data representing a first image and second image data representing a second image that is an image acquired by performing additional recording on the first image; a region specifying unit that specifies a region, where additional recording is performed with respect to the first image, of the second image in accordance with the first image data and the second image data acquired by the image acquisition unit; and a partial-image recognition unit that recognizes a partial image recorded in the region specified by the region specifying unit.