Biometric modality: Hand geometry – what is it?
Hand geometry biometric systems incorporate the salient features of finger geometry, but also include the surfaces of the hand itself and its side profile. Images are taken while the hand is kept palm down on a support plate and kept in position by the use of guide pegs. The length, width, thickness, and surface area of the individual’s hand is measured and recorded. Multiple features and measurements are extracted during this process. Several images of the same hand are often taken in order to produce a single stored template that has sufficient detail for identification purposes. These images and the supporting data are then filed in a database and are used to authenticate the identity of the enrollee in subsequent encounters when the subject’s hands are imaged again and compared with the reference images to confirm or reject the identity claim.