1. An image processing apparatus comprising: an image obtainer configured to obtain a first image and a second image, the first image being an image generated by image capturing of an object as an original image or generated by expanding part of the image generated by the image capturing of the object, the first image including a first object image, the second image corresponding to an image captured at a higher image capturing magnification than that for the first image, and the second image including a second object image corresponding to part of the first object image; and a processor configured to perform an estimation of one of the original image and a degradation function in the image capturing by using the second image as a constraint condition, and configured to produce a third image whose resolution is higher than that of the first image by performing calculation processing using the first image and a result of the estimation.