Since 1080P full HD technology has been widely used in video surveillance, television broadcasting, smartphone, HD technology becomes common in our daily life. People are eager to pursue much higher resolution, many television manufacturers launched 4K ultra HD TV into market, meanwhile a few IP camera manufacturers released 4K ultra HD IP camera + video recording resolution in security exhibition, 4K ultra HD becomes next trend for HD video surveillance application. What's 4K? How does 4K technology use in video surveillance application? What's current problem for 4K ultra HD technology?
4K comes from earlier DCI (Digital Cinama Initiative), it's a defined digital cinema resolution DCI 4K (4096x2160 pixels, 24fps). Until 23 August 2012, ITU (International Telecom Union) released the ultra HDTV standard: ITU-R BT.2020, which is a landmark to UHD era. In reality, 4K and UHD are ultra high definition (UHD, or Ultra HD). ITU-R BT.2020 has defined the standard for ultra HD's resolution, fps, color range, UHD has 4K and 8K two phrases, 4K has 3840x2160 pixels resolution, total approximate 8.3 megapixel; while 8K has 7680x4320 pixels, approximate 33.20 megapixels. 4K support frame rate from 24fps to 120fps. In BT.2020 standard, has already cancelled interlaced scan, only contain progressive scan, which greatly improved the image quality. On color depth aspect, from BT.709 standard's 8bit increased to 10bit or 12bit. This improvement has play a key role to enhance the image's color depth and transition.
Currently, 4K is under rapid developing stage, 4K products become a hot topic, although there are many 4K products in the market, but mass production hasn't been achieved. Because the core component for 4K camera is still expensive including progressive image sensor and image signal processor. 4K's ultra high definition and large data also bring some problems including increased data storage space, high power consumption. Additionally, security manufacturers are still competing in low-end market, the demands for 4K ultra resolution are still low.
Undoubtedly, 4K ultra HD is coming. Currently, Hi-silicon offers 4K UHD camera solution which supports ITU Ultra HD (3840x2160, 30fps), and DCI 4K (4096x2160, 24fps), also back compatible with 1080P full HD resolution. 4K ultra HD IP camera's main feature is its ultra high definition, and color image, hence utilizing ePTZ technology can provide wide video surveillance coverage. This can be useful in some outdoor surveillance places such as plaza, gymnasium, airport, bus station, beach...and more.
Furthermore, compared with 1080p full HD, 4K ultra HD can provide much higher resolution, this can provide users much more details from image/video footage. For example, ultra HD video streaming, facial recognition, plate license recognition and other smart video analysis result will be more accurate. The development and application of 4K will promote the entire video security industry toward high definition, meanwhile high definition brings new economic growth point to security manufacturers.
Current H.264 main profile or high profile compression bit-rate can be controlled among 6 - 8Mbps for 4K camera, after the implementation of H.265 standard, the bit-rate can be reduced to half. On video storage aspect, the current mature HDD technology has already reached to 4T, after format a 4T HDD, the approximate storage capacity is 3620GB. One 4K Ultra HD camera stream video with 8Mbps, it will occupy approximate 3.52GB per hour, one 4T HDD can allow a single 4K Ultra HD camera to record for 42 days.
Concerning to decoder, so far we haven't found any 4K hardware decoder to enable camera to connect monitoring TV wall. But the common video player software supports 4K video displaying and outputting. Take low end Pentium G series CPU, decoding 8Mbps 4K vide will use 80% CPU sources, if by standalone graphic hardware card, the occupancy rate will be lower.
For the display, the dedicated 4K ultra HD monitor is still rare, while the Television manufacturers launched several 4K ultra HD television with cheap price, and can perfectly support 4K UHD video display.
We have already known 4K UHD is the trend and realized the prospects of this technology, the actual application of 4K ultra high definition still facing some challenges.
1) 4K Ultra HD image sensor and image signal processor haven't been mass production, cost is still expensive, which constrained the development of 4K UHD IP camera; the production of image sensor and chip-set are based on demands from market.
2) On bandwidth and storage aspects, even adopting H.264 high profession compression, 4K's bit-rate is still too large, the comprehensive development of 4K still need to wait for H.265 compression technology to improve compression rate, lower bit rate and bandwidth, as well as storage space.
3) For video displaying, low-end 4K UHD television has already used in residential users, but high end 4K monitor/device is still rare, and its price is expensive.
4) From the application point of view, 4K Ultra HD has not been widely used, including intelligent analysis technology for ultra-high-definition 4K data processing is a burden, if there is no good overall solution, 4K Ultra HD technology will still only stay in the laboratory stage.