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The use of security cameras has increased. Most of these cameras are on a 24-hour or 72-hour recording loop, recording and recording over, ad infinitum. Only when something of interest happens, like a burglary, do these recordings get viewed by someone. A few cameras may have human operators; even fewer use facial recognition software. Recent generations of security cameras provide high definition images which will go a long way to help identify and capture criminals. High intensity infrared emitters like Vishay’s SurfLight™ complement the high definition trend.
Unlike your video camera or smart phone, security cameras do not have blue, green or red filters to provide color nor do they filter out the near infrared. This is why security cameras only record black and white images. Because they need to work at night, they use infrared emitters to illuminate the field of view and the reflected light becomes the image that gets recorded. The image below is of a typical security camera loaded with 5 mm or T1¾ infrared emitters. Emitters used have wavelengths of 850 nm to 940 nm.
The efforts of Isao Echizen, Ph.D., Associate Professor at the National Institute of Informatics (NII) in Japan captured the spotlight last week. He has spent time designing infrared ‘glasses’ to mask or blur his features so that facial recognition software used in conjuction with security cameras is hampered.
The photo above is taken with a camera that is sensitive to infrared light. The purple lights are actually invisible to the human eye. They would be recorded by security cameras and would obscure the person’s features. In all likelihood, the persons face would appear as a bright or overexposed spot on the recording.
Is too much energy being spent on trying to fool the law instead of just following the law? Or is this necessity being the mother of invention?