Imaging Forensics

The March, 2010 issue of Advanced Imaging magazine included an article on the use of H.264 compression in security camera systems. I thought the article was interesting, except for a couple of statements that distortion is somehow acceptable in security systems. I sent a letter to the author of the article (Barry Hochfelder) and the individual quoted in the article (Marc Damhaut of Euresys), and decided to also post it here:

I am a forensic image analyst and was initially pleased when I saw the article on surveillance / security video in the March 2010 article of Advanced Imaging magazine. But then I read the quote by Mr. Damhaut that, “In surveillance, you can compress it without [worrying about] distortion of the image. … If there’s a bit of distortion in the image, it’s not a problem.”

Well, if the video is of a homicide suspect and it’s important to make an identification based on facial features, tattoos, clothing, height, etc. to either identify the murderer, or exonerate an innocent individual, then that ‘bit of distortion’ may be essential! I can’t tell you how many times I’ve worked on cases where surveillance / security video systems have had just a bit too little resolution or just a bit too much compression to see the detail needed.

The problem is with manufacturers, installers and consumers. The manufacturers think that this application isn’t critical; the installer places the cameras in bad locations, doesn’t install lighting, bases his determination of the resolution on a live feed rather than the recorded and compressed video, etc.; and the consumer is looking for low cost, large capacity systems with an emphasis on catching employee theft. No one in this mix considers the potential of the video from these systems in serious crimes – or, at least, they don’t investigate the requirements of the forensic video/image analyst.

I am writing to call your attention to the misconception that the image requirements in these systems is somehow less important than in other applications. The truth is that these videos may help an innocent person prove their innocence, or help put a murderer behind bars.

Regards,

George Reis
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Imaging Forensics
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