In Clear View

Megapixel cameras can actually help you see what is in the image

• By Ralph C. Jensen
• Mar 01, 2014

High definition and megapixel cameras play an important role in video surveillance applications. They can provide images that are more useful, with a higher quality of detail and have wider coverage than standard-resolution cameras.

In his book, Intelligent Network Video, author Fredrik Nilsson wrote, “Megapixel resolution is one area in which network cameras excel over analog cameras. A megapixel, fixed, network camera can be used in one of two ways. It can enable viewers to see greater details in an image, or it can be used to cover a larger part of the scene, if the image scale is kept the same as a nonmegapixel camera.”

“Megapixel resolution first hit the market in fixed and fixed dome IP cameras, and even today the technology can be found in all form factors, including PTZ domes and even covert IP cameras,” said Nilsson, who is also general manager Americas for Axis Communications.

Megapixel cameras come with a high-value proposition. For starters, the aim of a megapixel camera is to obtain a high-resolution overview of any given scene. Consider a shopping mall, for example. The primary goal of a camera installation may be to watch people and view their movements, or maybe the goal is to see if the parking lot is empty or nearly at capacity.

Megapixel can also be used in demanding situations where it’s needed to identify persons or objects in a scene.

“With a megapixel camera, an end user is going to see a good image,” said Scott Shafer, executive vice president at Arecont Vision. “For instance, before the megapixel camera came along, a sports arena would be a difficult place to cover. Now, it is the right camera to use in this type of venue, where it quite possibly will help reduce the number of cameras needed and in use.”

Megapixel cameras are used in a number of key industry verticals, helping to address some video surveillance challenges. Nilsson reminds dealers and integrators what some prime opportunities may be for this type of solution.

City surveillance. Megapixel network cameras provide high-resolution, video streams from locations where it is necessary to clearly identify people and objects, or to get a larger overview while viewing live or recorded video.

Government buildings. Megapixel cameras provide the exceptional image detail necessary to facilitate the identification of people and to record evidence of any suspicious behavior.

Retail. A drastic reduction in theft and shrinkage can result from effective video surveillance. Megapixel network cameras can either provide an overview of a large part of a store—without any blind spots—or offer highly-detailed images of the sales counter area.

School and campuses. The use of megapixel resolution cameras in hallways makes it easier to identify students.

But Nilsson often reminds security professionals that the term “megapixel” only refers to one aspect of image quality: the number of pixels in an image. It is a term better suited for the still photography world instead of the video world, he says, because megapixel format as such does not guarantee frame rate, aspect ratio or color fidelity.

This is where, Nilsson says, HDTV-compliant video has made an impact on the surveillance world, “By following the SMPTE standard for HDTV, user’s receive a wider 19:9 field-of-view to see more of the scene, are guaranteed smoother, full frame rate video, can trust that the video’s color fidelity matches the real world, and that they’re getting 720p or 1080p resolution.

“This is why we watch football games at home in HDTC, not megapixel,” he said.

Speaking of football, Shafer said that many NFL stadiums are making the change to megapixel cameras, and while individual teams compete on the field, security staffs from various stadiums talk about what works best to keep the venue safe and secure for all. When it comes to security, there is no competitive feeling, but rather a desire to provide safety.

“The reason we are sold on megapixel to begin with is because it is less costly to deploy than standard IP cameras,” Shafer said. “Areas that were difficult to cover in past-times can now be covered with high-quality, high-resolution images. Using H.264, the image is compressed much better, and it makes using the camera much more efficient.”

Megapixel cameras are often put in place to allow an infrastructure to catch up with the latest technology.

Brian Carle, chief technical officer of Salient Systems, said that megapixel cameras are typically considered a best-of-breed, security solution and are a technical driver in the industry.

“They are a strong differentiator between using megapixel and analog; that’s obvious to everyone,” Carle said. “There is a very strong argument for megapixel, if not for one reason but to reduce the camera count and provide a much better image.

“More consumers want megapixel cameras, even though they require more storage capability and bandwidth. From our point of view, as a VMS software provider, the video management solution has to be designed to handle higher-resolution video, meaning there must be more processing power to handle the throughput.

“What megapixel cameras offer is higher-quality video at the scene.”

At the scene, for instance, could mean retail security where point-ofsale monitoring is necessary to clearly see every item a customer is buying or situations where it would be necessary to identify a face. End users can even get high-detailed images by installing a network camera with a telescopic lens or a zoom lens to get closer to the area of interest.

“A network camera that offers megapixel resolution uses a megapixel sensor to deliver an image that contains 1 million or more pixels,” Nilsson said. “The more pixels a sensor has, the greater the potential it has for capturing finer details and for producing a higher-quality image.

“In the video surveillance industry, some best practices have emerged regarding the number of pixels required for certain applications. For an overview image, it generally requires 80 pixels from ear-to-ear to identify a person.”

While megapixel technology has changed the industry, Nilsson says there are some drawbacks.

“As in any surveillance installation, there is no way one camera fits all solutions,” Nilsson said. “Integrators need to understand when megapixel is the answer for an application, and when it isn’t.”

Nilsson said that lower light sensitivity, expensive lenses, sacrificing frame rate and increased storage can all be potential tradeoffs when using megapixel. Yet, he said, that by sticking to industry standards and following along with Moore’s Law, megapixel and HDTV cameras will only get better.

Integrators agree that megapixel cameras are the future. Commercial businesses are moving quickly toward the megapixel revolution, primarily because of the resolution of the image. The detail of the image upon playback is so much better that the end user should never have any worries about what they are looking at.

“The megapixel camera offers better coverage and search functionality,” said Ray Gilley, president and CEO of ISI Security. “We also see the cost of megapixel cameras inching down. As an integrator, we sell more megapixel cameras than anything else.”

Gilley noted that 90 percent of their orders during 2013 were for megapixel cameras.

“People who deploy megapixel cameras find them to be more scalable and easier to use when growing their security system,” said Gilley. “What we find is that the buyer actually becomes its own IT department.”

Until the next great innovation in camera technology, security-industry professionals seem to agree that megapixel cameras are not to be lightly regarded, but in fact are the popular choice for protecting employees, assets and facilities.

This article originally appeared in the March 2014 issue of Security Today.