On statistical problems with face identification from photographs

SUMMARY Automatic identification of faces from a database given a digital view is becoming increasingly important. The question arises whether or not there can be a face identification system similar to the fingerprinting system, where a certain number of matches are regarded as sufficient to identify the person in the database. We first give a very general review of the topic of facial measurements and indicate some deep statistical problems. We then analyze a database of photographs. Certain characteristics of the population are provided, such as the modes of variation and correlation structures using shape analysis. The data involve angles as well as distances. The principal component analysis for angular data is discussed, its conversion into landmark data is established and the two approaches are compared. A new approach of anchor shape analysis for specialized distances is discussed.