An image identification apparatus includes: a memory; and a processor coupled to the memory, the processor being configured to perform processing, the processing including: acquiring a contour image where pixels indicating a contour of a subject are extracted from an input image; detecting pixels of 3 points or more over the contour from each of regions in the contour image, which are separated by a predetermined distance in a vertical direction or a horizontal direction; calculating, for each combination of pixels of every 2 points among the detected pixels, an intersection point of a perpendicular bisector of a line segment having 2 points as end points and a distance between the intersection point and one of the detected pixels; and identifying, from the input image, a circle having the intersection point as a center of the circle and the distance as a radius.