Enhancing image quality with right system

 

 

The more pixels a digital video image has, the greater its detail. Images with a greater number of pixels are much clearer, and more detail is preserved when various parts of an image are magnified during a forensic investigation.

 

 

 

Designers of IP-based video systems have an unprecedented oppor -tunity to improve the performance of their systems. The opportunity involves choosing the right network camera and comes in the form of the superior resolution of megapixel cameras.

In fact, the higher image quality of megapixel network video cameras is among the greatest advantages that IP-based systems have over older standard resolution technologies (analog or VGA). Let’s be direct: Any standard-resolution camera still in use at the edge of an IP network represents a missed opportunity.

 

 

 

VGA versus megapixel resolution
The more pixels a digital video image has, the greater its detail. Images with a greater number of pixels are much clearer, and more detail is preserved when various parts of an image are magnified during a forensic investigation. A standard VGA camera provides 640x480 resolution (about 307,200 pixels, or a 0.3-megapixel image), while a 10-megapixel camera offers 3,648x2,752 resolution to provide 10,039,296 pixels. In between are megapixel camera choices to meet any application.

The ideal resolution clearly varies according to the application. What megapixel video does is greatly expand the number of useful choices. Each customer’s application and expectation of image quality should be matched to the right megapixel camera. While a 5-megapixel camera might be an excellent choice in some projects, it is not ideal for all scenarios. If an application requires faster frame rates or different light sensitivity, for instance, a 1.3-, 2- or 3-megapixel camera might be a better option.

However, any megapixel camera is an improvement over VGA and analog. Even the new HDcctv standard, which adapts HDTV technology from the consumer market (roughly equivalent to 2.1 megapixels at 1080p or 0.9 megapixels at 720p) limits choice and doesn’t allow resolution to be adapted to the application.

Opportunities for megapixel imaging
The opportunities for megapixel imaging expand beyond the aesthetic appeal of clearer images. The true value in megapixel video comes in greater functionality, whether it’s the ability to read the license plate on a passing car or to see the numbers on a playing card in a casino.

Another aspect of greater functionality is the ability to view larger areas with fewer cameras, resulting in systems that offer better performance at less cost than analog and VGA. One example is the use of panoramic cameras. An 8-megapixel panoramic image of a large area covering either a 180-degree or a 360-degree view provides a 6,400x1,200 pixel resolution. Panoramic cameras use four imagers, 2 megapixel each, to provide the overall 8-megapixel imaging area. They can take the place of up to 24 standard-resolution or analog cameras to view a large area with comparable results.

But what happens when you “zoom in” to an image to see the real details? In the case of VGA-resolution cameras, you often get a pixilated view that shows little detail. However, higher-resolution megapixel cameras capture that detail. Users can zoom into any part of an image in real-time or on recorded video to extract forensic information.

In effect, megapixel video allows the use of “virtual” pan-tiltzoom (PTZ) combined with far better coverage. Whether viewing a parking lot or a casino floor, a mechanical PTZ camera can watch only one of 10 fields of view it surveys at a time; that leaves nine fields of view without coverage. Covering those additional fields with added cameras increases the cost. Single-sensor megapixel cameras with wide-angle lenses and panoramic multi-sensor cameras capture the entire scene, all the time, and users can zoom in on any area of the image, live or recorded, while maintaining full field-of-view recording. Use of megapixel cameras is, therefore, less expensive than and superior to mechanical PTZ devices in most applications.

In addition to a variety of resolutions, users and integrators need a variety of camera types in order to match them to the right application. Gone are the days when megapixel cameras came in a limited number of models. Today, megapixel models include day/night cameras, panoramic view cameras, compact cameras, 1080p HD and greater-than-HD resolution cameras, low-cost cameras for price-sensitive applications, all-in-one dome cameras, infrared bullet cameras, vandal-proof cameras and cameras resistant to environmental hazards. Such a broad camera line serves the varied needs of mainstream video surveillance applications.

System considerations
Managing bandwidth and storage are important considerations when designing IP-based video surveillance systems. However, the emphasis is on managing these considerations -- they should not be seen as obstacles. Faster frame rates can eat up bandwidth, but a frame rate of less than 30 fps (full-motion or real-time) will usually supply sufficient video data. Many megapixel cameras offer capabilities to enable NVRs to request lower-resolution video streams during non-critical periods.

Scenes with constant movement also require extra bandwidth and storage. The chosen compression method can greatly influence bandwidth utilization. H.264 video compression, the newest compression standard, has eliminated bandwidth and storage concerns related to megapixel video. H.264 produces video quality equivalent to the familiar JPEG compression method with a major reduction in bandwidth. Easing the integration of megapixel cameras requires collaboration between camera manufacturers and suppliers of video recording technologies. The collaboration ensures smooth integration of systems. Camera suppliers also work with technology partners for tighter integration with complementary products, including servers, storage and other systems, which make the integrator’s job even easier. Partnerships have paved the way for simplified integration of systems that incorporate IP/megapixel video with highly intuitive software programs. Additionally, there is a wide range of megapixel cameras available today with selectable resolutions and frame rates that can easily be adapted to general surveillance applications. This provides system designers with a high degree of flexibility and confidence in their designs.

 

 

The ease of network system connectivity has also contributed to the rapid rise of IP/megapixel imaging. In the old analog days, every single camera had to have a “home run” coaxial cable running to the recorder, which increases cabling costs exponentially.

Today, networking infrastructure enables connection of multiple cameras with fewer cables, and the use of Power-over-Ethernet even supplies power to cameras on the same Cat-5 cables that carry video and control signals. It’s an efficient and simple installation solution that eliminates the need to have a separate power source to the camera. It’s easy to create a spreadsheet comparing costs of a system using megapixel cameras versus standard IP or analog camera technologies. Such an exercise will highlight the effect of using fewer cameras or of eliminating the need for mechanical PTZ devices.

It allows you to factor in all the costs, including infrastructure savings, reduction in the number of components (cameras, housings, cabling), installation and support savings, and operator savings. Users and integrators alike can benefit from understanding the strong return-on-investment case that underlines the benefits of the technology in terms of operational advantages, as well as the long-term total cost of ownership.

 

 

A new level of image quality
A key to taking advantage of the benefits of megapixel video is for system designers to change their mindset and that of customers.As the market becomes educated about megapixel video, the technology will continue to gain traction. The superior resolution of megapixel cameras, their versatility and overall cost-efficiencies are indisputable based on actual installations and metrics.

 

 

The developments related to H.264 video compression make bandwidth and storage requirements of megapixel images comparable to those of standard-resolution images. And megapixel cameras are also comparable in price to standard-resolution cameras, especially when you consider the ability to use fewer megapixel cameras to cover larger areas than analog cameras can and the related savings on infrastructure costs. Integrators and users should overcome any remaining misconceptions with knowledge and join their colleagues in markets all over the world to embrace the immense promise of megapixel video.