Forensic image retrieval and processing are vital tools in the fight against crime e.g. during fingerprint capture. However, despite recent advances in machine vision technology and image processing techniques (and contrary to the claims of popular fiction) forensic image retrieval is still widely being performed using outdated practices involving inkpads and paper. Ongoing changes in government policy and the reduction of forensic service budgets increasingly require that evidence be gathered and processed more rapidly and efficiently. A consequence of this is that new, low-cost imaging technologies are required to simultaneously increase the quality and throughput of the processing of evidence. This is particularly true in the burgeoning field of forensic footwear analysis, where images of shoe prints are being used to link individuals to crime scenes. This research looks at using one such approach to image fingerprints, shoeprints and even possibly tyre prints and is based upon frustrated total internal reflection imaging. This technique can be used to acquire images of regions where an object is in intimate contact with a rigid surface.
This research utilises inexpensive waveguide based imaging devices to acquire images of regions where an object such as a finger, a shoe, or a tyre contacts a hard surface.The researchers' interests lie in the development of the devices and the open source software required to operate them. They are also looking at how these devices can be used to obtain information about the local pressure exerted below a contacting object.
Watch your step! A frustrated total internal reflection approach to forensic footwear imaging, J. A. Needham & J. S. Sharp, Scientific Reports 6, Article number: 21290 http://www.nature.com/articles/srep21290Accessible biometrics: A frustrated total internal reflection approach to imaging fingerprints, N.D. Smith and J.S. Sharp, accepted for publication in Science and Justice, 2017