The New 4k IP Cameras – A Writeup of Axis and Hikvision’s Webinar
What is 4k?
4k refers to the screen resolution of the images produced by the cameras, outputting at 3840 x 2160, however it’s far more than simply a bigger image. 4k is also used as an umbrella term for a standard of video recording that applies to multiple aspects of the production; not just the image size.
4k IP cameras typically adhere to HDTV standards, which mean that as well as outputting high resolution images, they are also capable of shooting at 30-120fps, 16:9 aspect ratio, and have a vastly superior colour fidelity than that of previous cameras, meaning that they’re far truer to life than ever before and even more effective at capturing important details in a scene.
What benefits does 4k bring?
There are a number of direct and tangible benefits that 4k technology will bring, as we’ll go into below:
With the much greater resolution, the software that processes the image and allows for smart interaction becomes increasingly more effective. In his talk within the webinar, James Marcella talks briefly about the three levels of analytics detection, recognition, and identification, also known as Johnson’s Criteria, for visual devices:
- For detection, that is, detecting an object within the scene, it requires only a minimum of 1 pixel per inch (PPI) resolution.
- For recognition, differentiating between objects within a scene, 3-4 PPI is required.
- For identification, matching a face to a database say, a minimum of 12 PPI, or 80 pixels for the width of a person’s face, is required.
These are all possible with current technology, however, to achieve the high PPI required for effective identification usually means having to use a very limited field of view (FOV). With 4k IP cameras, these can all be achieved whilst maintaining a wide FOV, meaning that as well as getting the detail required for smart security software, you’re also maintaining a large amount of situational awareness, capturing what is occurring in and around the scene as well as your target. This means that users are able to use fewer cameras for the jobs that previously would require a large system.
We touched above on the complete array of improvements that the 4k standard brings, and this leads to a number of implications regarding the use of surveillance footage captured by these cameras. The most apparent of these is that, as the images captured on 4k IP cameras are clearer and more accurate than ever, they’re even more effective than those of traditional lower-resolution IP cameras as evidence within a legal context. Ultimately, these kinds of improvements lead to both a higher rate of arrests for perpetrators of crime, a higher rate of stolen goods being returned to their owners, and hopefully a higher rate of deterrent for would-be criminals.
With such a large area captured by a single camera, the options for digital PTZ (pan, tilt, and zoom) are vastly improved with 4k IP cameras. This refers to the ability to take an image, either live as it is being recorded, or when viewing after the fact, and using software to zoom into a particular section of the image without loss of picture quality. This allows an operator to enlarge a chosen aspect of a scene, and move around the area of zoom, without the need for motorised components within the camera itself that would traditionally be used to do this.
While digital PTZ has been around for a while, it’s never truly been able to rival physical PTZ as accomplished by motorised cameras. However, with the advent of 4k, we’re seeing the technology come closer than ever before to that of traditional PTZ, and for a much, much lower cost. What this will hopefully mean in the future is far cheaper cameras than are available commercially today, that provide the full range of utilities currently only available in more expensive models.
It is not only the camera technology that is improving, but also the monitor technology alongside it to view the cameras on. This is being further helped by other factors, such as streaming services like Netflix, and also Blu-Ray, both now supporting 4k and meaning that it’s increasingly becoming an everyday technology. One of the best uses of these large 4k monitors is the ability to stream multiple HD cameras on the same screen. A 4k monitor will support 4 simultaneous 1080p streams in native resolution, or 8 720p streams. Long gone will be the days of a wall of monitors massively increasing the cost of large security camera systems!
What challenges does 4k bring?
Of course, with any new technology there comes new challenges to overcome, and in their talks both James Marcella of Axis and Doug Gray of Hikvision cover some of the more apparent ones that come with the developing 4k IP camera technology.
Clearly, with a greater resolution, more data is being captured by an IP camera than before, and so the storage requirements are increased. James gives some estimated average figures for a camera continuously recording at 25fps, using the typical H.264 industry standard codec, for 28 days of storage:
- 720p resolution – 342GB
- 1080p resolution – 770GB
- 4k resolution – 3TB
So, as you can see, there’s quite a jump in the 4k space requirements! Luckily there are a number of ways of combatting this. Both the cost of storage itself is lowering all the time, and compression technology is improving, meaning that more information is able to be stored. By and large the storage technology should keep up with the recording, meaning that this shouldn’t be too great a concern for someone looking at buying a system in the near future.
As with storage, 4k IP cameras increase the load dramatically on the average recording system due to the sheer amount of data they transmit. We’ve written previously about the new generation of Hikvision NVRs that come with 4k support, and both Hikvision and Axis have developed their own optimised codecs, the H.264+ and ZipStream respectively, that aim to reduce bandwidth usage by up to 50%. Looking to the future, a new codec, the H.265 is being developed and is increasingly available for use, and this may provide an additional reduction in bitrate for 4k IP cameras.
As with many things, it’s a case of scalability; the higher quality the image, the more powerful the computer needs to be, the faster the network needs to run, the bigger the storage space needed, etc. You can’t have one without all of the others!
WDR and Low Light Recording
This is an interesting quirk of the technology. As you’d imagine, a 4k camera is the same physical size as your typical 3MP or 4MP camera, meaning that the internal imaging sensor is also roughly the same size. However, the pixels on that sensor are much smaller than on those of lower resolution models, due to there being so many more of them crammed into the same space.
This leads to a number of problems regarding a loss of wide dynamic range (WDR) and quality of low light recording compared with more conventional current digital security recording. Axis released a white paper in 2014 about the complexities of achieving good WDR in surveillance footage, and in many ways the problems are compounded by the increase in complexity that comes with 4k cameras.
Visual noise, caused by the different exposures in each pixel given by the amount of light in a scene, is obviously one of the major limiting factors when the number of pixels is increased substantially, and so noise reduction technology is having to be improved quickly in order to keep the images usable in low light environments.
This is something we can expect to improve over time, as the technology matures and becomes more common. Until then, the use of strong infrared (IR) LEDs greatly improves low light images captured by 4k cameras, as well as the use of more conventional night-lighting.
Where are 4k IP cameras currently being used?
The exciting thing is that 4k IP cameras have already been in use for some time, and as the technology becomes cheaper to produce we can expect to see its wide-spread adoption by both commercial and private users. At the end of his talk, Doug Gray outlined a few areas in which its currently used, and how the technology specifically has been applied by different agencies:
- Large public areas – the ability to use very wide lenses with 4k cameras, and still retain high detail on distant areas via the use of digital PTZ, has meant that they’re perfect for use in large public areas, such as city squares and sports stadiums. It’s meant that the actual number of cameras can be reduced, as a single 4k camera is able to do the job of a few lower resolution models, lowering costs generally for both public and private bodies implementing them, as well as reduced infrastructure required to get the systems running.
- National security – because of the very high level of detail that 4k IP cameras provide, as well as the host of other benefits that come under the 4k standard spoken about above, they’re perfect for use in high-risk surveillance, where detail is so vitally important. They’ve been utilised by national security agencies around the world for this very reason.
- Retail – the key use here is in loss prevention, due to the excellent abilities in these cameras for both identification and facial recognition. For stores it’s vital to be able to identify repeat offenders, and capture fine movements and detail in order to minimise stock loss.
- Video walls – as mentioned above, the use of single 4k monitors to replace large multi-screen setups is becoming increasingly common, and proves to be one of the best indirect benefits of this new technology.
We hope you’ve enjoyed our writeup of the excellent webinar given by Axis and Hikvision, in conjunction with Security System News. 4k technology is an exciting emerging field that’s producing a lot of very promising results, and we’re looking forward getting some of the new 4k IP cameras in the use-IP office some time in 2016 to test for ourselves, as well as expanding our current range of 4K cameras as they become more available and affordable. Watch this space in the coming months, as we’ll post regular updates on news, tech, and other 4k products that we receive in!