Images of imprints, e.g. made by items of footwear, are displayed on a
computer screen. Any identification features A-D which are present in the
image are tagged and the length of all the lines 1-6 joining the tagged
features are calculated and the distance information is added to a
database together with the images themselves. The polygons defined by the
lines 1-4 are independent of the positioning or orientation of the image
and are used to retrieve images likely to originate from the same article
by applying search criteria which retrieves records containing distances
falling within selected bands.
