HD Video Surveillance
the point of entry and exit. Instead, standard definition or VGA cameras can be employed, and can record at reduced frame rates. This ability to use lower resolutions and
reduced frame rates is achieved because all you are seeking from these units is evidence to support continuity! The HD streams have already captured evidential quality images. The lower resolution footage only needs to establish what the individual did whilst on site. If an incident occurs, it’s a relatively simply job to link the continuity video with the HD footage.
In such a case, a site may only require two
HD cameras, and can make savings by utilising lower specification cameras in less essential areas. Additionally, the extra bandwidth and storage used by the HD streams can be offset with the reduced requirements for lower-resolution lower- bandwidth video. It is interesting that when networked
then does that mean that HD isn’t more cost- effective than standard definition video? Actually, it doesn’t. HD video surveillance can be significantly more cost effective, if it’s used in the right way!
Picture perfect
End users seek HD video because of its higher quality, which makes it ideal for positive identification and evidential purposes. Often camera positioning is something of a compromise, and as a result images of someone entering a building - for example - are not always as clear as they might be. This is where HD comes into its own. The aspect ratio gives a wider field of view, which offers better opportunities to capture a high quality image. The HD resolution ensures a clearer picture with higher levels of detail, and the secondary benefit of increased forensic examination allows that image to have moderate levels of digital zoom applied to it without pixelation becoming an issue. If a building has two entry points, then two
HD cameras will ensure that the system captures high quality real-time images of everyone that enters and leaves that site. These cameras will require slightly increased levels of bandwidth and storage over standard definition cameras, but this can then be offset across the system. Throughout the rest of the building, there no longer is a need to positively identify individuals, because this has been achieved at
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cameras first appeared in the security sector, one of their downfalls was that resolution had to be kept low because of bandwidth and processing issues. Whilst VGA cameras didn’t achieve acceptance (because analogue cameras had higher resolutions), the growth of HD has actually created a reason to consider VGA units - as continuity devices! Whilst this example looks at a single scenario, it does not take a great leap of imagination to translate it to a host of other applications. The HD video effectively creates the evidential stream for positive identification, and supplementary information can then be gathered at reduced resolutions. HD video isn’t about replacing other devices or finding a way around installation problems. It’s about delivering a higher quality image that always delivers what is expected. You know that it will offer high quality real-time images, and will do so unless you actually restrict the system intentionally.
In summary
Designing a system using HD isn’t that different from designing one with standard definition cameras. The important elements are to consider where to capture higher quality images, why you need that higher quality, and how the images will be used. For many, HD is still a new approach, so much of the ‘popular’ thinking needs to be considered carefully, or you may compromise the final system.
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