1. Identity document digital image correction method comprising the steps of: identifying the type, class and issue of a presented identity document from a plurality of features in a digital image thereof; retrieving from a reference identity document repository, information about a reference authentic version of an identity document of the same type, class and issue as the presented identity document; allowing a user to select at least two features in the digital image of the presented identity document calculating the distance between the two selected features; determining from the information retrieved about the reference authentic version of the identity document, the distance between corresponding features in the reference authentic version of the identity document; calculating a scaling factor γ x, y from the ratio of the distance between the two selected features in the presented identity document and the distance between corresponding features in the reference authentic version of the identity document; applying the scaling factor to a one or more measurements of features in the digital image of the presented identity document.