Happy Feet - research into baby footprints as an infant biometric

The pressing infant biometric problem is to find a biometric means to identify infants cheaply, reliably, and automatically. Physical traits of infants are tiny, delicate, and grow rapidly. The authors focus on a novel area of friction-ridge skin as a potential answer: the ball under the big toe. The ballprint is readily accessible, with more features and larger ridges than a fingerprint. The authors followed 54 newborns for 2 years, capturing their ballprints with an adult fingerprint scanner within 3 days of birth, at 2 months, at 6 months, and at 2 years. The authors show the growth of the ballprint is isotropic rather than affine during infancy. The isotropic growth rate from birth can be measured by the change in inter-ridge spacing, which the authors show precisely mirrors change in physical length from birth, as recorded by World Health Organisation for large, diverse infant populations. From 2 months of age, by using isotropic scaling to compensate for growth, the authors successfully matched good quality images with 0% equal error rate using existing adult fingerprint technology, even for captures 22 months apart. These findings flag the value of ballprints as a practical means of infant identification, by themselves, or together or sequentially with other biometrics.