Over the past 10 years we have seen surveillance cameras deliver ever-improving image quality. Today’s cameras can feature videos with amazingly detailed resolution at high frame rates.
Wide dynamic range technology enables today’s cameras to capture detailed images even in scenes with complex light, while advanced image sensors allow for high-resolution color video even in extreme low-light conditions.
Inevitably these advances in technology also increase the amount of data created, and therefore requirements in terms of network bandwidth and data storage.
Intelligent compression methods can be used to cut bitrates by 50% or even more. The critical question, however, is which 50% to lose! It makes little sense to invest in high-quality video surveillance cameras if important details are lost when the bitrate is reduced to facilitate transfer across the network, or to reduce the storage capacity needed.
The Axis solution to intelligent video compression is Zipstream, a technology developed in 2015 and continually updated and improved upon ever since. It dynamically reviews video footage, recording critical detail in high resolution and full frame rate, while significantly reducing the bitrate for parts of the video that aren’t essential.
Capture the things that matter, and compress the things that don’t
If a scene under surveillance never changed, a camera could be configured once to deliver the best results at the optimum level of image compression. However, this is an unrealistic scenario. From an empty hotel lobby in the middle of the night to a train station during rush hour; to a mall entrance hall before Christmas to an office at the weekend, every situation is in a near constant state of change. It is therefore essential to have a surveillance camera system with the flexibility to adapt to these environments, optimizing both image quality and bitrate, capturing forensic levels of detail when needed, and avoiding periods of recording ‘high-resolution nothingness’.
Take for example the empty hotel lobby in the early hours of the morning. While there is very little happening at that time, cameras might still be recording in high resolution at full frame rate, using significant bandwidth and storage. In such a situation, Zipstream compresses the least important data (in this case just about everything!) – reducing bitrate significantly, in some cases to almost zero, while the camera still provides constant surveillance.
Even in situations where there is a high amount of movement – such as a busy mall entrance during Christmas shopping season – intelligent compression will dynamically review the video in real-time, compressing the static parts of the image with little value while maintaining the resolution of the most critical detail.
It isn’t always easy to optimize intelligent video compression technology so that devices capture what matters and compress what doesn’t. Sophisticated technologies now exist that offer more intuitive optimization, making it quicker and easier to cut down on storage without compromising on footage quality. For example, Zipstream now comes with an optional one-click profile select feature, “Storage profile”, that automatically selects the most suitable encoding and compression settings for improved bitrate savings and easier configuration.
Intelligent video compression: no longer a “nice to have”
As the quality of video surveillance cameras improves almost exponentially, intelligent video compression has quickly moved from a ‘nice to have’ to absolutely essential: without it, data transfer and storage demands will become almost impossible to support. With that comes the risk of losing details critical to investigations, or an inability to retain recorded footage long enough for full and comprehensive analysis. It would be the ultimate irony if the quality of surveillance cameras resulted in data demands so high that few could afford to realize their benefits.
