The Megapixel Difference
Understanding Megapixel cameras
Pixel, short for Picture Elements, is a single point in a graphic image. Graphics monitors display pictures by dividing the display screen into thousands or millions (MEGA) of pixels, arranged in rows and columns. The pixels are so close together they appear connected. The more pixels your have, the more resolution, or “clarity”, you have in your image.
HDTV/megapixel technology enables cameras to provide higher resolution of video images than analog CCTV, giving you the ability to see more detail and a wider coverage area. While the cost per camera may be more, you can see larger areas with fewer cameras. With an HDTV or megapixel camera the resolution is a minimum of three times better than an analog CCTV camera. The increased resolution allows for you to zoom into archived data and extract details such as license plates, faces, lettering, what a suspect may be holding, and much more. Yes, you can do all these things with a zoom analog PTZ camera, but what are the chances it will be aimed and zoomed into the right location at the precise moment an incident occurs.
We understand not every customer has a budget like the Pentagon. That is why our systems are capable of using megapixel cameras in key locations and mixing in analog CCTV cameras where the details may not be as critical. For instance, in a small business on a budget it maybe best to utilize a few megapixel cameras at the entrances and use CCTV cameras to view other activities. Then at a later date as megapixel cameras continue to become more affordable, we can upgrade your system, on your budget. Most importantly, we build design and service our Digital Video Recorders or Network Video Records so they can always be upgraded or repaired, not thrown away.
How Many Pixels do I need?
A conventional CCTV camera providing 4 CIF resolution offers a resolution of 704×480 pixels (NTSC) after the signal is digitized in a DVR or video server, which corresponds to a maximum of 400,000 pixels. In the surveillance industry 20 to 30 pixels enough to represent one foot of a scene in most applications. For facial identification the demands are as much as 150 pixels per foot. This means to be able to Identify a person passing through a 7 feet wide by 7 feet high area the camera needs to provide a resolution of 1,050×1,050 pixels, which is slightly more than 1 megapixel. There are many other considerations that need to be taken into account including, lighting, available bandwidth, available storage and camera placement. You will also need to create a separate network for the surveillance cameras to prevent bandwidth problems.