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Annoying Aspects of CCTV (Part 1)

A photograph in a recent issue of that fine CCTV Image magazine, the organ of the CCTV User Group, showed a spanking new CCTV control room. The proud owners had invested in a bank of monitors often known as a video wall. Nothing unusual there, you might say to yourself. Indeed. (My thoughts on how to save money, power consumption and cooling costs in your control room by avoiding the need for a video wall will wait for another day.)
CCTV image with 4:3 aspect ratio

CCTV image with 4:3 aspect ratio

In CCTV where, disappointingly, end-users’ technical advice can come from an ex-policemen who doesn’t really know a pixel from a pixie or from a salesman who thinks “codecs” is spelled “codex” (because he once read The Da Vinci Code), we often see regular CCTV images being inappropriately stretched across widescreen monitors. Please, no.

Look at it, then think about it. Take the normal 4:3 CCTV picture and stretch it over a typical 16:9 LCD and you end up with a sideways distortion of 33%. That’s a whole 1/3!

CCTV image with 16:9 aspect ratio

CCTV image with 16:9 aspect ratio

Why should this annoy us? Because it’s surely ridiculous to take a picture from a normal CCTV camera with its 4:3 aspect ratio and dumbly stretch it over a big LCD or plasma screen designed for 16:9 widescreen pictures. Stewie Griffin from Family GuyThere’s no advantageous level of detail being created; just a profound sideways distortion that indicates a disregard for proper system design. So, is any benefit whatsoever? Nope. Can you imagine the CCTV operator calling the police on the radio and telling them, “the suspect is a IC1 male wearing yellow and with a curiously wide head….Yeah, looks like Stewie Griffin off that Family Guy cartoon”?! But more seriously, why tell responders to look for a “fat man” when it’s the video display that has falsely added the weight to his appearance?

This common arrangement, to me, shows ignorance. But that doesn’t stop it being a very common sight in CCTV control rooms around the UK and probably the rest of the world too. Ok, if they’ve bought widescreen LCD monitors in anticipation of displaying HD CCTV images in the future (which are 16:9) then that’s acceptable forward planning. But, please, in the meantime show 4:3 pictures properly. At worst, doing it will give you a black margin down each side of the screen. It’ll be correct for the humans to watch and it will look fine. Honestly.

It flabbergasts me that our industry so rarely bothers to get this right. Of course, some diligent folks do exist, but they are rare, and the aforementioned so-called ‘consultant’ numpties can fool an unwary client just enough to get themselves hired. Please, for your own benefit, make sure you hire CCTV consultants who know what they’re doing. One advantage is that your pictures will be shown to your CCTV operators accurately. The pictures are the reason you bought CCTV in the first place.

Keeping come back, folks. Who knows, one day I might post something that not purely a dig at the other practitioners in the field! 😉  Still, I think these points need to be made by someone. 

Until next time; stay focused.

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