Just Pixels, But A Lot More
Still, don’t jump to the conclusion that ever more pixels is the better way. The shift to megapixel and HD cameras must come with a shift in decision making by enterprise security leaders and their integrators to matching of resolution to application.
“Our role is protection in all forms ranging from traditional physical security and information security to fraud and investigations – anything related to security,” says Jerry Garland, chief security officer for Magellan Health Services, with headquarters in Avon, Conn.
Measuring SharpnessThere continues to be dueling marketing brochures over a standard measure of the level of sharpness required in video surveillance applications. No doubt, the more pixels on a target, the higher the resolution. But networking, video analytics, Best Buy, image storage, transmission, increasing use of video for forensics, Walmart, processing at the edge, megapixel lenses and tumbling prices all are elements accelerating the growth of megapixel cameras.
Wait a minute: Best Buy? Walmart? Many buyers, integrators and manufacturers all agree that residential HDTVs in family rooms and man-caves have shown the advantages for security-centric HD.
Back when, the family camcorder created the economics for CCDs in security video cameras. A recent report by the Cable & Telecommunications Association for Marketing showed that, while 35 percent of households owned an HDTV in 2008, the number grew to 53 percent in 2009. Now consumer acceptance of HDTV is wetting the appetite of security for similar image resolution but with the added benefit of standards driven by general broadcast and cable users. And as HDTV video quality also comes down in price, megapixel cameras are becoming an option for many seeking a move to IP video.
• 1080i (1,080 lines of resolution scanned in alternate fields consisting of 540 lines each) is the most commonly used HDTV format, and has been adopted by PBS, NBC, and CBS (as well as satellite programmers) as their HDTV broadcast standard.
• 1080p, in which 1,080 lines of resolution are scanned progressively, is also in use, providing the most detailed high-definition video image that is currently available.
Details in InvestigationsBeyond display for real-time monitoring, HD provides the detail needed in investigations and for evidence. If there is an incident that occurs where an individual makes a claim against a venue or when a business needs to identify people and activity after the fact, HD has the pixel muscle.
Among choices are cameras ranging from 1.3 megapixel – very popular – and 2, 3, 5, 8 and 10 megapixels. It is also good to look at the ability of the cameras to provide full motion frame rates, even though some end users may dial down the frame rate based on transmission requirements.
Evaluating CamerasEvaluating HD cameras is a challenging task. The National Center for Spectator Sports Safety and Security’s National Sports Security Laboratory at the University of Southern Mississippi has been handling the assignment. For example, during a game-day event at the M.M. Roberts Stadium at the University of Southern Mississippi, a dozen high-definition cameras were positioned outside and inside the stadium complex to monitor fan activity. Two national surveillance companies – Avigilon and Pixel Velocity – teamed up with NCS4 to test the equipment and related procedures. “Video surveillance has surfaced as the top issue facing the security industry right now,” says Dr. Lou Marciani, NCS4 director. “The goal with our lab is to vet security solutions for sports at all levels, from college to professional. There is no one else right now doing what we are for collegiate venues through this lab.”
Broadcast BenefitsSo Valley Ag Software, a Tulare, Calif.-based network software developer, installed Axis high-resolution network cameras atop radio towers throughout the Valley. The broadcast-quality video from the network cameras streams over an Internet service provider’s backbone directly to the news station and CBS47 Web site. Uniquely, “viewers can log onto www.cbs47.tv and control the live PTZ cameras, if we aren’t operating them,” points out Chad McCollum, CBS47 news director. And, because the unmanned network cameras operate 24/7, the newscasts can include live pictures as well as compressed time-lapse views of weather as it progresses through the Valley.
Higher Pixels for Special AppsMegapixel and HD cameras wed well with the Internet, too. For example, among technology displayed in Las Vegas at the ISC West show was a new indoor mini-dome from Honeywell that provides 720p images at extremely low bandwidth for significantly reduced storage requirements, even in low light. It features a Web-based menu to let operators view and control cameras from virtually anywhere.
But before that day arrives, there is the ability to have HD without the IP, or so goes technology from SG Digital. It has a video surveillance system using serial digital interface
Dispelling Some Megapixel Myths
Megapixel Myth: When Megapixel isn’t Megapixel. So what are the differences between today’s cameras? There are a number of factors to consider. First, from a specification sheet perspective, look at a camera’s resolution. Cameras today can vary from VGA to tens of megapixels.
Let’s say you need to cover an area 64’ wide by 48’ deep at a forensic level of detail (40 pixels-per-foot). Taking some liberties to simplify this example (lenses don’t actually deliver a square field of view), you would need 64 x 40 pixels wide (=2560) by 48 x 40 pixels deep (=1920) or a total of 4,915,200 pixels (2560 x 1920). If you use a 0.3 “megapixel camera” (translation: VGA camera at 640 x 480), you would need 16 of them to cover the desired space. If you use a 5 megapixel camera, one will do the job.
Now let’s calculate costs. If you choose a VGA camera that costs about $200, you will pay 16 x $200 = $3200. Divide the cost by the total number of pixels and you come up with $0.00065/pixel. Alternatively, if you select a high-end, reliable 5 megapixel camera that costs about $1200, using the same calculation your cost would be $0.00024/pixel which is 63 percent cheaper — that’s before you consider installation costs like cabling, power and housings.
Megapixel Myth: Interlaced is Not Very Progressive. Another myth centers on details like what type of imager used. If someone talks about an HD1080 camera, they are only giving you half the story. Is it HD1080p or HD1080i? The “p” stands for progressive scan which delivers much higher quality video, especially when there is motion. HD1080i cameras, on the other hand, are “interlaced” cameras that stitch two low resolution images together to make a high resolution picture, which often results in poor image quality when there is scene motion.
The above is provided by Paul Bodell of IQinVision and is part of a three article series, The Truth about Megapixel.