Application of D'Arcy Thompson's coordinate transformation approach to clinical genetics photographs using image processing techniques.

The coordinate transformation approach outlined by D'Arcy Thompson for analysing biological shape was extended using modern computerised image processing techniques so that it could be applied to photographs for the study of patients with syndromes of altered facial morphogenesis. Photographs digitised at a resolution of 512 by 480 pixels were subjected to 'rubbersheeting' transformations using a fast microcomputer. Starting with a photograph of a normal child, a single application of the rubbersheeting algorithm produced features such as an upturned nose quite simply. Other facial anomalies may also be recreated with multiple applications. Preliminary results suggest that this technique may be a useful tool in attempts to understand and analyse the changes in facial configuration in a variety of syndromes with facial anomalies.