Capturing Crystal Clear Images With Megapixel Technology
a&s International | Date:
Megapixel surveillance is not a new concept — its applications and benefits are starkly clear. What has changed are smarter cameras, taking advantage of the added pixels and a better understanding of illumination in real life. In the first of a two-part report, A&S examines how smarter megapixel cameras are getting; the second part looks at best practices for optimal performance.
The big picture for megapixel surveillance cameras looks bright, in the wake of the recession. HD and megapixel cameras are expected to make up nearly 30 percent of network camera shipments in 2011, according to IMS Research. By 2015, it is forecast that more than 60 percent of network cameras shipped will be of megapixel resolution.
The resolution increase has a noted effect on the whole surveillance system. While a 2.1-megapixel or 1,080p HD image is six times larger than a D1 image, the additional pixels require a bigger pipe to transmit more data. The infrastructure and storage costs for megapixel are well-documented, with ROI and TCO being used as arguments in favor of bigger pictures. The fate of megapixel is linked to the future of IP networks, with HD forecast to make up most high-resolution cameras compared to megapixel, according to IMS.
Megapixel surveillance requires careful planning, but the benefits of added resolution boost the accuracy of analytics. Edge devices take advantage of faster processors, resulting in smarter use of pixels. Analytics can help reduce bandwidth, as an event will trigger video streaming, rather than constantly sending the same still images over the network. A more distributed architecture puts less strain on networks and makes life easier.
Clarity is the main driver for megapixel. “At the end of the day, you're putting in a security system to protect life and provide evidence in a court of law,” said Stephen Moody, Security Development Manager for ViS Security Solutions, an integrator in Ireland.
Cracking the Code
H.264 is the de facto standard compression for megapixel cameras, due to its efficiency in crunching large data files into smaller ones for transmission and storage. As compression evolved from M-JPEG's stills to MPEG-4 and now to H.264, a variety of profiles yield differences in performance. With 17 profiles in all, three are the most common: baseline, main and high, said Sachin Khanna, PM for CCTV, Bosch Security Systems.
By profile, the baseline is appropriate for video conferencing; the main profile is good for broadcast video; and high profile is most applicable for HD broadcast video. “H.264 requires a fair amount of processing power for encoding and decoding; this may limit the camera's frame rate and dictate the NVR platform to achieve the desired performance,” said Rich Pineau, CTO of Oncam Global.
Most H.264 profiles stem from 2-D applications, with not all profiles being capable of integration. “Even if both cameras are H.264 and the manufacturers are partners, the system could still not work,” said Patrick Lim, Director of Sales and Marketing for Ademco Far East. “The I/O and output are hard to integrate. Some engineers say it's easy to plug and play — there's no such thing.”