To achieve faster search processing in the search processing of a similar image, based on a feature value of each of a plurality of keypoints of a human body included in an image, the present invention provides an image processing system 10 including: a target image acquisition unit 11 that acquires a target image; a skeleton structure detection unit 12 that performs processing of detecting a keypoint of a human body included in the target image; a first verification unit 13 that extracts a first reference image whose relationship with the target image satisfies a first extraction condition, from among a plurality of reference images, based on the detected keypoint; and a second verification unit 14 that extracts a second reference image whose relationship with the target image satisfies a second extraction condition, from among the first reference images, based on the detected keypoint.