Application

The system developed by the forensic experts will even enable police officers on the beat to generate clear and unambiguous source material for potential identification. According to guidance issued by the British Home Office, police officers should capture at least five images of every person taken into custody. The better the quality of these images, the easier it will be to compare these later with image and video evidence relating to criminal acts. This inspired the idea to develop “HALO”, a forensic system for biometric identification of potential suspects.

Each “HALO” system is equipped with four uEye LE machine vision cameras from IDS Imaging Development Systems GmbH. These particularly powerful CMOS cameras deliver the five required photographs of potential perpetrators from different angles in a single step with a level of quality that far surpasses the current standard.

The system simultaneously uses software developed by Acumé Forensic to capture biometric facial data – unique to every individual – together with each image recorded. The algorithm used is capable of differentiating between more than 1 million features of a human face. The information captured includes details of skin colour and texture and the shape of the eyes, ears, nose and mouth. The system also detects colour variations in the skin on an individual's face, as well as the physical dimensions of the various features and statistical deviations, such as how much the face varies from an average face. HALO creates a record of the person's unique facial features, so that they can subsequently be identified even if only the tiniest part of their face is visible.

The 18 megapixel sensor in the USB 3.0 camera ensures that no detail is missed. As a result, distinctive features can be highlighted, making information contained in an image, or even an incomplete image, as valuable as a fingerprint. A 3D model of the face is generated, enabling an unprecedented standard of quality in the field of automatic identification.

As a result, images of suspects taken from CCTV footage can be used for identification even if the quality is poor or the individual is not looking directly at the camera. "Once our algorithm has learned a face, it can recognise them even from just their ear”, explains Professor Hassan Ugail, Professor for Visual Computing at the University of Bradford, who is involved in developing the system.

To improve the chances of criminals being tracked down using facial identification, the Acumé Forensic team led by system developer Peter Lowery integrated a UI-3580LE-C-HQ colour camera with a 5 MP CMOS sensor from onsemi, plus three UI-3590LE-C-HQ cameras into their HALO system. These three cameras are equipped with a CMOS colour sensor from onsemi, which ensures richly detailed images – from VGA, through 4K cinema, to full 18 MP resolution. BSI (back side illuminated) pixel technology ensures high-level light sensitivity, making this sensor ideal for high-resolution visualization tasks. The criminal investigators were also impressed by the compact housing of the uEye LE camera, with its miniature dimensions of 47 x 46 x 26.3 mm. The cost-effective, space-saving project camera is suitable for a broad range of uses, not least thanks to its C/CS-mount lens mount, which also enables the use of wide-angle lenses.

The forensic experts also conducted a thorough investigation of the IDS camera's compatibility. The many illustrative sample programs provided in the DS Software Development Kit helped these super-sleuths to track down the right camera supplier. Thanks to the IDS Software Suite's .NET interface, the USB machine vision cameras were easily integrated into Acumé's application. "The greatest benefits offered by IDS are the wide product range, an extensive software package and excellent support", affirms Peter Lowery.