An image processing apparatus includes an image acquisition unit that acquires a captured image of an object captured through an imaging lens, a coordinate transformation unit that performs coordinate transformation for the captured image such that a sagittal resolution in a direction tangent to circumference having a center of an imaging surface as an origin and a tangential resolution in a radial direction perpendicular to the tangential direction are close to each other at a designated spatial frequency, and a resolution enhancement processing unit that performs a rotationally-symmetric resolution enhancement process for the coordinate-transformed image. According to this aspect, a rotationally-symmetric filter can be used for the resolution enhancement process. It is possible to prevent an increase in filter size or to perform a process at a high speed. It is possible to prevent a process from being complicated due to the use of the filter for coordinate transformation.