On Using Gait in Forensic Biometrics

• Published in: Journal of forensic sciences Vol. 56; no. 4; pp. 882 - 889
• Main Authors: Bouchrika, Imed, Goffredo, Michaela, Carter, John, Nixon, Mark
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2011; Wiley Subscription Services, Inc
• Subjects: Algorithms; Biomechanical Phenomena; Biometric Identification - methods; Biometrics; Confidence; Databases, Factual; Forensic engineering; forensic science; Forensic sciences; Forensic Sciences - methods; Gait; Gait - physiology; gait analysis; gait biometrics; Humans; Kinematics; Measurement; people identification; posture matching; ROC Curve; Software; Translations; Videotape Recording; visual surveillance
• ISSN: 0022-1198; 1556-4029; 1556-4029
• DOI: 10.1111/j.1556-4029.2011.01793.x

:  Given the continuing advances in gait biometrics, it appears prudent to investigate the translation of these techniques for forensic use. We address the question as to the confidence that might be given between any two such measurements. We use the locations of ankle, knee, and hip to derive a measure of the match between walking subjects in image sequences. The Instantaneous Posture Match algorithm, using Harr templates, kinematics, and anthropomorphic knowledge is used to determine their location. This is demonstrated using real CCTV recorded at Gatwick International Airport, laboratory images from the multiview CASIA‐B data set, and an example of real scene of crime video. To access the measurement confidence, we study the mean intra‐ and inter‐match scores as a function of database size. These measures converge to constant and separate values, indicating that the match measure derived from individual comparisons is considerably smaller than the average match measure from a population.