The security industry adopted Full HD (2MP) as its digital IP CCTV resolution standard as recently as 2010.
Five years on and Full HD is making way for Ultra High Definition (Ultra HD), 4k technology, a new resolution standard which provides 8MP video streaming. In this article, Paul Scott of SBG, explains the place Ultra HD video has in the security industry and why it is here to stay.
What is 4k resolution?
The term 4k, shortened from 4k2, simply refers to the number of pixels produced in a 4k video stream, which is a massive 3840 x 2160 pixels (approximately 4k x 2k) or 8 megapixels. 4k provides four times the resolution of the current Full HD standard, which is a mere 1920 x 1080 pixels, or 2MP, in comparison.
Does using 4k cameras make commercial sense?
Just like Full HD before it, 4k technology has been derived from the TV broadcast industry. Its rapid acceptance by the consumer market has helped to drive down component costs and increase their availability. 4k delivers exceptional scene coverage, clarity and detail, with four times the resolution of Full HD, however, the increase in cost of the resulting 4k CCTV cameras is not so great. 4k cameras achieve greater site coverage than Full HD cameras, so the real cost savings come from the need for fewer cameras on site and the associated reduction in cabling, configuration, recording channels, VMS software licenses and more. The end user can also be assured that greater scene coverage is achieved and fewer site incidents are missed with 4k.
Typical applications where 4k has been embraced include city centre surveillance systems, traffic control and management, airports, car dealerships, parking, sports stadiums and retail parks, where large areas must be viewed simultaneously and a high level of detail is required for evidence.
Low light sensitivity.
Low light sensitivity in megapixel cameras is reduced as the number of pixels in the camera sensor increases. Therefore, 4k cameras are not ideal for use in poorly lit areas where they are less sensitive than 2MP and 1.3MP cameras. However, recent improvements in CMOS sensor technology has improved sensitivity for all megapixel cameras, making 4k far more effective in low light than it was.
Night time surveillance has also been greatly enhanced by significant performance developments in high power LED technology. The LEDs are now capable of illuminating a scene equivalent to the coverage and range of a 4k surveillance camera, without an increase in power consumption,
Lens compatibility and availability.
Many lens manufacturers already make a selection of inexpensive, 4k compatible, C/CS mount CCTV lenses. The rapid development of mobile phones with built-in, multi-megapixel cameras has helped to drive down costs and increase availability in this area.
Resolution, frame rate and network bandwidth.
The bandwidth required to transmit a 4k, 8MP video stream at 25 FPS is between 12 and 20 Mbit/sec, using H.264 compression. This is four times that of Full HD, 2MP video. However, the number of cameras used in an Ultra HD security system is far less than in a Full HD one, helping ease bandwidth demands. H.265, with twice the data compression capability of H.264, is expected to be commonly available later this year.
Until the wide availability of H.265, many manufacturers have developed specialist compression technologies, like Grundig’s “High Profile” compression, which offer extremely efficient compression and transmission benefits and significantly reduce bandwidth use with 4k technology.
The majority of Full HD CCTV systems are operated in real-time, at 25 FPS. This is not necessary with 4k, Ultra HD video, as 6 – 12 FPS is sufficient, reducing the data transmitted and associated bandwidth demands. 4k systems are more commonly used in forensic searching where the 8MP video is examined retrospectively. The large amount of data within each image and its wide scene coverage ensures that no evidence is missed. The camera’s electronic zoom functionality then allows the operator to examine the video and provide detailed coverage of events.
Upgrading and compatibility.
To take full advantage of 4k technology, all the components used to capture, transmit, record and display 4k images must be Ultra HD. The IT infrastructures used are invariably ahead of the security industry’s requirements, so most switches, routers and PCs are already compatible.
Many VMS platforms will operate with 4k cameras, making an upgrade surprisingly simple. The VMS will often record the 4k stream and use lower resolution sub streams for display, live and analytics functionality, optimized for the viewing device and again saving bandwidth. Grundig 4k cameras produce up to four, ONVIF compatible, video streams for this purpose, and Grundig already produces 4k displays.
A convergence of new technologies has contributed to the early adoption of 4k technology. These include 8MP lens development; high bandwidth IT infrastructures; the prevalence of VMS solutions in IP CCTV applications; efficient compression technologies such as H.265; and cost-effective camera production. These and the fact that fewer cameras are needed for comprehensive site coverage, with all the associated installation savings, make 4k technology a viable solution for current applications. They also confirm 4k’s place as the next resolution standard for the security industry.