An image processing apparatus includes at least one processor executing the following processing including: image acquiring processing that acquires an image of an object in which a plurality of subjects, which are individually identifiable, are provided in a predetermined direction, the image including at least two subjects among the plurality of subjects; identifying processing that generates an information image including a feature amount of each of the subjects included in the image acquired in the image acquiring processing, and identifies each of the subjects by comparing with an information image stored in advance in memory; and output control processing that measures a distance between the subjects, each identified in the identifying processing, and controls to output a measurement result.