1. An image analysis device, comprising: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the image analysis device to: acquire an original image including a designated image region which is rotationally symmetric with respect to a first point; generate a reference image by rotating the original image about a second point on the original image; calculate a correlation value between the original image and the reference image at each relative position by virtually and relatively moving the original image with respect to the reference image; detect the position of the first point in the original image, according to a geometric model indicating a relative positional relationship between the first point and the second point in the original image, on the basis of the amount of rotation of the reference image about the second point at a relative position between the original image and the reference image where the correlation value is the maximum and a vector indicating a deviation between the second point of the original image and the second point of the reference image; and specify a range of the designated image region in the original image, based on the detected position of the first point and a distribution of brightness values of pixels in the original image.