Fires on film

Smokers who sneak a cigarette at work beware. CCTV cameras will soon be
watching out for the first signs of a fire. Sentec, a British company based in
Cambridge, has invented a way for digital CCTV systems to detect even the
tiniest of flames, often before any smoke is visible. Flames flicker with
characteristic frequencies, says Sentec chief Mike Black, so the new system
simply looks for pixels changing at these frequencies. This lets it
automatically identify a fire in just a few seconds, sounding an alarm minutes
before smoke detectors.