Palm print recognition is a biometric authentication method based on the unique patterns of various characteristics in the palms of people’s hands.
Palm print recognition systems use a scanning device or a camera-based application, along with associated software that processes image data from a photograph of an individual’s palm and compares it to a stored record for that person. Palm prints are counterparts to fingerprints, including similar details. As is the case with fingerprint scanning, palm scanners use optical, thermal or tactile methods to bring out the details in the pattern of raised areas (called ridges) and branches (called bifurcations) in an image of a human palm, along with other details including scars, creases and texture. Those three methods rely on visible light analysis, heat-emission analysis, and pressure analysis, respectively. Palm scanners may require that individuals touch their hands to a screen or may be contactless.
Palm prints and fingerprints are often used together to enhance the accuracy of identification. A handprint, by virtue of covering more skin area, includes more identifying details, making false positives all but impossible and simultaneously making intentional falsification much more difficult. In other situations, such as criminal investigations, a full or partial palm print may sometimes be obtained when fingerprints are absent. A criminal might, for example, wear gloves to avoid leaving fingerprints but inadvertently leave a partial palm print when a glove slips during the commission of a crime.
The first recorded application of handprint recognition was in 1858, when Sir William Herschel recorded the prints of Indian civil service employees working under him and matched them to new samples taken on paydays to ensure identification.