Drunk-Spotting with a Thermal Cam

Thermal cameras can be used to spot drunk people, because alcohol increase blood flow to certain areas of the face and makes them warmer. As the article also points out, thermal cameras can also be used to identify which tents at “Occupy” events are actually being slept in at night, and legal types may recall thermal cameras being used to spot houses with grow ops. Ironically, the latter case is the only one which is an illegal violation of privacy.

It’s interesting to note that glass is a barrier to the 10µm-wavelength radiation that thermal imagers detect, so this is only useful for spotting drunk drivers if they’re rolling in a convertible with the top down.

On the other hand, if you’re walking around looking for people with impaired judgement who will easily fall for a line of BS, this is an extremely useful tool.

Security tip: don’t get drunk. Ever. Sorry.

Question: Why does whiskey — and particularly scotch — in low doses seem to produce a different (more talkative?) quality of inebriation than other liquors?


“Computer scientists have published a paper detailing how two algorithms could be used in conjunction with thermal imaging to scan for inebriated people in public places.

In the paper, published in the International Journal of Electronic Security and Digital Forensics, Georgia Koukiou and Vassilis Anastassopoulos of the University of Patras in Greece detail two different algorithms they are working on that focus on data gathered from a subject’s face — alcohol causes blood-vessel dilation at the skin’s surface, so by using this principle as a starting point the two began to compare data gathered from thermal-imaging scans. One algorithm compares a database of these facial scans of drunk and sober individuals against pixel values from different sites on a subject’s face. A similar method has been used in the past to detect infections, such as SARS, at airports — though a study carried out at the time of the 2003 outbreak warned, “although the use of infrared instruments to measure body surface temperatures has many advantages, there are human, environmental, and equipment variables that can affect the accuracy of collected data.”
A second algorithm is used to map out the different areas of the face. The pair found that, when inebriated, an individual’s nose tends to become warmer while their forehead remains far cooler. To use this information against the database with the first algorithm, a second algorithm was necessary to identify and differentiate between features.

The system could, the paper argues, be used to avoid embarrassing and unfounded reproaches by police officers and officials, who generally make assumptions based on behaviour and appearances alone.

Thermal imaging is already used to spy on potential criminals and was even used to see if the Occupy LSX protestors were in their tents at night at St Pauls. Practical applications like the one Koukiou and Anastassopoulos are suggesting might save police embarrassment and avoid undue disturbances. However, it might also annoy a fair few sociable late-night drinkers harmlessly going about their business while having their bodies unwittingly scanned in an intrusive breach of personal privacy.”


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