Shoe wear patterns and pressure distribution under feet and shoes, determined by image analysis

A method is outlined for extracting contours of the pressure exerted by feet on the ground, either directly or through the soles of shoes, and of the wear patterns on shoe soles. The method is applied to two types of image: shoeprint images made in the laboratory, and pedobarography images recording the distribution of pressure under the foot during a footstep. The first procedure in extracting the information from images involves low pass filtering in the Fourier domain, performed by a microcomputer and frame-grabbing system. The boundaries of the regions in the resultant images are then extracted from the filtered images to display the shape of constant pressure areas and of the general shoe-wear.