1. A method of determining the orientation of an image of a human body to determine whether the image is in the normal erect position or not comprising the steps of obtaining image signals carrying the image information of the human body, obtaining the distributions of the image signal levels in the vertical direction and horizontal direction of the image, and comparing the pattern of the distribution in the vertical direction with that of the horizontal direction, whereby it is determined whether the image is in the normal position based on the comparison.