The real truth about megapixels & HD

Learn more and bust through the myths


"The most important thing for integrators to know is that HD implies a specific megapixel aspect ratio, frame rate and resolution (16x9 aspect ratio at 30fps with either a 720p or 1080p resolution). Because HD designates a subset of megapixel options, integrators should also know that other aspect ratios, frame rates and resolutions are available that may, or may not, suit a customer's situation better than HD.

Important considerations when selecting the appropriate megapixel camera for an application include aspect ratios, frame rates, frame type and resolution. For example, 1.0MP and 2.1MP cameras, typical deliver 16x9 aspect ratios while 3.0MP and 5.0MP cameras deliver 4x3 aspect ratios. Therefore, integrators should consider whether a wider aspect ratio is in fact best for the specific application. Similarly, progressive, or 'P' cameras deliver full frame rate while interlace cameras, typically designated 'I' alternate between even and odd horizontal lines each frame-therefore delivering only half the stated frame rate. And finally, what resolution is most appropriate for a customer's application?"

3 Tips for Integrators

1.High definition surveillance is a network-camera technology, meaning that it cannot be used in older, analog CCTV applications. What HD offers is the ability to dramatically improve resolution of surveillance images so that users will no longer experience the grainy, pixilated images they have traditionally seen.

2. Several new technologies are involved with network HD cameras today. Chief among them is the use of the new H.264 compression technology which combines built-in audio synchronization, dramatically improved compression of HD Images, and intelligent predictive motion analytics to eliminate the "halo" effect seen on older compression technologies like MPEG-4.

3. Select the right encoding format for the intended use, H.264 for video monitoring and MPEG for vivid, high resolution image recording. -- Robert M. Gailing, National Sales Manager, Security Products, SANYO North America, Chatsworth, Calif.

HDcctv Alliance

According to the HDcctv Alliance (www.highdefcctv.org), High-Definition Closed Circuit Television, or HDcctv transmits uncompressed and without being encapsulated in TCP/IP. HDcctv hopes to bring all of the benefits claimed by megapixel IP cameras to the CCTV market with the ease of use of conventional analog CCTV equipment. It's designed to be a drop-in replacement for existing analog CCTV, requiring only a change of camera and receiver. It digitally transmits full HD HDTV signals.