Minimum requirements for taxicab security cameras.
Zeng-S; Amandus-HE; Amendola-AA; Newbraugh-BH; Cantis-DM; Weaver-D
J Transp Technol 2014 Jul; 4(3):216-255
Problem: The homicide rate of taxicab-industry is 20 times greater than that of all workers. A NIOSH study showed that cities with taxicab-security cameras experienced significant reduction in taxicab driver homicides. Methods: Minimum technical requirements and a standard test protocol for taxicab-security cameras for effective taxicab-facial identification were determined. The study took more than 10,000 photographs of human-face charts in a simulated-taxicab with various photographic resolutions, dynamic ranges, lens-distortions, and motion-blurs in various light and cab-seat conditions. Thirteen volunteer photograph-evaluators evaluated these face photographs and voted for the minimum technical requirements for taxicab-security cameras. Results: Five worst-case scenario photographic image quality thresholds were suggested: the resolution of XGA-format, highlight-dynamic-range of 1 EV, twilight-dynamic-range of 3.3 EV, lens-distortion of 30%, and shutter-speed of 1/30 second. Practical Applications: These minimum requirements will help taxicab regulators and fleets to identify effective taxicab-security cameras, and help taxicabsecurity camera manufacturers to improve the camera facial identification capability.
Motor-vehicles; Humans; Men; Women; Mortality-rates; Morbidity-rates; Safety-equipment; Safety-measures; Safety-practices; Photographic-equipment; Photography;
Author Keywords: Taxicab Homicide; Facial Identification; Photographic Resolution; Dynamic Range; Lens Distortion; Motion Blur
Shengke Zeng, Division of Safety Research, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV
Healthcare and Social Assistance; Transportation, Warehousing and Utilities
Journal of Transportation Technologies