Source of information: http://www.iqeye.com/iqeye/images/uploads/File/Marketing/IP_Video_Surveillance_with_Megapixel_Cameras.pdf
Coupling powerful IP video surveillance management software, like Milestone XProtect Enterprise, with powerful megapixel IP network cameras (like the IQeye from IQinVision) makes a whole that’s much greater than its parts. Such sophisticated software offers many advantages when used with these and other cameras. One of its greatest capabilities is the ability to handle an unlimited number of cameras, even megapixel cameras, across multiple sites. This ensures a video surveillance system that can grow with your organization. Another important advantage of robust video surveillance management software is that it makes better use of server resources (microprocessors and memory) to handle incoming video data more efficiently. The most advanced IP video surveillance management software enables simultaneous digital multi-channel video and audio recording, and live views of up to 64 cameras per server. Equally important to look for, is how efficiently a software product uses client hardware resources (microprocessor, memory and graphic cards) on the system your staff will use for viewing. This will determine how many megapixel images you can view on a client at a time. The best software makes maximum advantage of client capabilities on a variety of platforms. The best IP video management software will also make your security staff more efficient by providing a more productive user environment. Features like multi-stream views, for instance, allow multiple people to access the same camera’s live views and even independently zoom into different parts of the image. This can be important when both local and remote staff are monitoring a situation. Advanced IP video surveillance management software even allows one view to have multiple windows open with different zooms from the same camera. Another feature you’ll find in such full-featured software is digital zoom for even fixed cameras. With this feature, you can zoom in on live images provided by cameras that have no zoom feature. Naturally, the higher the resolution of the camera, the higher the quality of the image obtained by the zoom. On a megapixel camera, the results can be stunning. Another feature to look for is ability of the software to keep and record the big picture view while you zoom in on one aspect of the image. With advanced IP video surveillance management software, you can even make printouts or AVI movies of each independent image — the zoom view and the full view. Another thing to look for in software is whether it’s designed to deliver the best use experience on a wide range of devices. The best solutions use video quality optimization to automatically maximize live and playback windows for the device on which they’re being viewed. To save storage space, some IP video surveillance software products enable you to receive at a higher frame rate while recording at a lower frame rate.
Analog cameras have a great disadvantage in resolution compared to digital megapixel cameras. Analog resolution is limited by NTSC standards (used in North America) at 704 x 480 pixels and PAL standards (used in Europe and many other parts of the world) at 704 x 576 pixels. If you multiply these numbers you get the total pixels. (“Pixel” is short for “picture element” and generally thought of as the smallest single component of an image. Pixels are useful as a way of comparing camera resolution.) NTSC and PAL standards limit analog resolution to a maximum of approximately 400,000 pixels or 0.4 megapixels. This is enough for general surveillance in the areas these cameras are generally asked to cover, but often not enough for forensic evidence. If they are tasked with covering an area wider than 16’ wide, the resolution isn’t sharp enough to identify faces and read license plates. What’s more, due to technical and cost restraints inherent in the analog camera itself and in transmission through coax cable or video encoding/decoding from analog to digital and back to analog, you generally see much lower resolution from analog cameras by the time the video reaches the viewing monitor or printer. Remember, too, we’re talking about the best analog cameras. Many analog cameras in use for surveillance today fall well below the maximum resolutions allowed by NTSC or PAL standards. IP network cameras, on the other hand, have a distinct advantage because they record and transmit digital images with no analog conversion necessary inside the camera or any need for a video encoder. Consequently, they do not suffer any loss of quality resulting from these conversions. Thus, with IP network cameras you get every pixel you pay for. Instead of blocky, blurry images, you can get crisp, clear images of faces, license plate numbers, and whatever else appears before the camera.