How to overcome common playback issues; by Gordon Smith, Managing Director of GVD.
A lot of CCTV systems work really well on live view recording and give you decent quality live footage. However what happens when you try to play back archived footage? After all isn’t this the feature that most people want? They want to see what happened after the event.<br><br>Traditional DVRs are mostly programmed to compress archived footage at a lower quality resolution than what they are set for live viewing. This is to save on disk space. Ordinarily, a D1 or 4CIF resolution analogue camera will give you a good quality live image. However try viewing archived footage on most analogue installations and you will find that the recorded footage has been set to 2CIF, to maximise the length of the archive time and reduce the storage to the DVR hard drive.<br><br>See the example. In the first image you can see an ACTi 1.3 Megapixel indoor dome camera giving you the full view for general surveillance and then on digital zoom you can clearly identify the individual in either live recording or on playback.<br>In the second picture using a camera set at a 4CIF resolution you can achieve a reasonably good overall surveillance view and when zoomed in you can see that the individual’s face become blurry and less readily identifiable. If you knew the person already, you would probably be able to verify their identity but by and large in an instance of crime you will not know the person. Remember these pictures are based on live view in 4CIF.<br><br>In the third picture we can see footage of the same individual taken from the archive which has been stored at 2CIF. Because the number of pixels in the image has reduced considerably, the general overview for surveillance has become compromised and the individual appears further away from the camera and harder to make out. When the image is zoomed in to see the individual’s face, the picture becomes blocky and blurry – something that we are all used to seeing on the likes of Crimewatch where poor video footage rarely leads to capturing the bad guy. <br> <br>If you are installing or upgrading a video surveillance system, bear in mind that your clients won’t thank you if they can’t see the registration plate or see the robber’s face on playback of their recorded footage. <br><br>Some 64 per cent of businesses have been victims of crime in the last year at a cost of £2900 for each business, according to Ann Swain, Home Affairs Chairman of the FSB (Federation of Small Businesses). With crime, and the fear of crime,a major concern, 21 per cent of small businesses that incurred a cost because of crime installed or upgraded their CCTV system. For this kind of investment wouldn’t you want to be able to give your customer the best quality footage on playback?
