Facial recognition can be a valuable identification tool when fingerprint identification is unavailable or impracticable.
Just like automated fingerprint identification, facial recognition can provide law enforcement agencies with a valuable tool for multiple public safety applications. Whie fingerprints assure higher rates of accuracy than face recognition can, facial recognition provides benefits when fingerprint data does not exist, is not easily shared between agencies, or when multiple independent verification methods are desired. Additional applications include identity verification in the field and intelligence gathering, as well as crime prevention and investigation.
A Brief Background
Since the advent of photography, both government agencies and private organizations have kept photo collections of people. Indeed, photos have made their way onto personal identification documents, from passports to informal membership cards issued by schools and athletic clubs.
Before the use of computers to recognize faces was even considered a possibility, facial recognition was already the subject of a great deal of research. Examples include:
- Development of identification line-up techniques in which a witness is confronted with a group of physically similar people, one of whom is a suspect. The witness must then decide whether one of the persons in the group was present at the scene of the crime or not.
- Work done by Bertillon1 on face classification. In order to recognize individuals who were repeatedly arrested, Bertillon developed means by which portraits could be sorted by common morphological characteristics—the specific shapes of the different parts of the face—and thus an individual’s prior photo could be found without having to resort to browsing through large collections of portraits. This classification is known as the “portrait parlé” or spoken portrait.
Facial recognition with good quality images
The first attempts to automate facial recognition started in the 1960s in semi-automated mode. The approach essentially consisted of checking the correspondence of measurements between different facial feature locations (the corners of the eyes, the hair line, etc.) These first attempts were not very successful as faces are by nature very animated and measurements between characteristic points are also affected by viewing orientation.