Facial image comparisons of morphed facial imagery

Abstract

Facial image morphing is a technique whereby two or more faces are blended together to create a new face (the morph). Apps and open source software are now freely available to create morphs. While morph creation is predominantly for entertainment value, it is also a method being used to create facial imagery for use on fraudulent identity documents. This study sought to answer two questions. First, would participants accept a morph persona (an identity created using only morphed facial imagery) as a credible identity? Second, could participants match faces that had been used to create a morph (so-called constituent faces)? Results showed that morph personas were credible, being correctly matched more often than alternative images of real people. Further, results showed that propensity to declare a constituent face a match to its morph was dependent on the type of morph, with morphs made using two faces more likely to yield matches than those made using eight or 16 faces. A follow up similarity study on faces selected showed that even if a constituent face was selected it would more than likely have been ruled out as a match following a more thorough one-to-one comparison.