Analysis of low-pass filtered shoeprints and pedobarograph images

摘要

The shape and extent of the general wear apparent on a shoe sole contains information about the foot function and gait of the wearer. A method of analysing this information and comparing it to the foot/ground pressure pattern is given. Shoeprint and pedobarograph (PBG) images are transformed into the Fourier domain, passed through a Butterworth filter, and then transformed back to the spatial domain. From the filtered images a series of four-connected contours are extracted, showing the shape and extent of the general wear patterns in shoeprint images and the pressure patterns in dynamic PBG images. An appropriate contour is selected from each image. The contours are normalized for position and size and then compared pairwise for shape. The method of comparing contours is illustrated with contours from PBG images, taken from three subjects; these are compared with each other to indicate the degree of inter- and intrasubject variation.