The real truth about megapixels & HD

Learn more and bust through the myths


Today, while an IP camera may or may not be a megapixel camera, a megapixel camera may or may not be an IP camera! It may be an HD-CCTV camera-and an HD-CCTV camera is always a megapixel (720p or 1080i) camera."

Steve Gorski-General Manager for the Americas-MOBOTIX Corp., New York, N.Y.

"HDTV is a widely adopted standard that is well-suited to the application for which it was originally designed--consumer entertainment. HDTV has a maximum 1920 x 1080 resolution made possible with the implementation of H.264. Ideal for watching movies from devices such as an iPhone or Blu-ray player, the H.264 codec scales extremely well, from small screen to widescreen HD cinematic viewing. However, the key strength of H.264, low bandwidth streaming, is in fact its greatest weakness when used for the purposes of video surveillance. Why is this the case? First of all it is important to note that when it comes to capturing video from a security camera, what's most importance are the areas where changes or movement occurs. H.264 actually displays movement in such a way that looks very good to the eye, but only while streaming. When pausing the video and extracting still images for the purposes of object or facial identification, the still images tend to look blurry and lack detail. This is because H.264 applies a lot of compression to any changes in the scene - hence the reason why it is so bandwidth efficient. This is ideal for watching movies, because the human eye can't detect the loss of quality where there is movement in each frame, but not suitable for surveillance applications.

From the outset, it was clear to MOBOTIX that what customers want is the ability to be able to pause the video at any place in the stream and extract high quality stills to positively identify the moving object or person. MPEG based codecs, such as H.264, simply do not fulfill this requirement.

MOBOTIX has in fact, created a video delivery technology called MxPEG that is, to date, the world's first and only codec specifically designed for security applications. The patented technology enables the extraction of stills for positive identification, without any compromise of image quality - no blurring and no loss of detail. It also goes one step further, delivering the best of both worlds--bandwidth efficiency plus higher quality video streaming and image stills. No other video technology in the surveillance market delivers that combination. MxPEG currently offers 2048 x 1536 image resolution which is 51 percent higher than HDTV. In fact, MxPEG is a key contributing factor as to why MOBOTIX owns nearly 40 percent global share of the high resolution IP camera market segment."

Paul Bodell-Chief Marketing Officer-IQinVision, San Juan Capistrano, Calif.

"According to Wikipedia, 'HD video refers to any video system of higher resolution than standard-definition (SD) video and most commonly involves display resolutions of 1280x720 pixels (720p) or 1920x1080 pixels (1080i/1080p).'

A number of manufacturers who are lacking in megapixel products would have you believe HD is something different or somehow better than megapixel. Truth is, HD is just marketing. In our experience, here is what most people assume about HD:

1- It is widescreen format (16:9), not standard format (4:3)
2- It is H.264
3- It is high frame rate

The reality is that megapixel cameras have been able to deliver widescreen format, H.264, and a high frame rate for years now, they just weren't marketed as HD.

The key questions integrators should ask when they are evaluating 'HD' camera technology are:

1- What is the resolution in pixels (i.e. HD720 = 1280 x 720 = 0.92 Megapixels)?
2- Is it progressive scan (HD1080p) or interlaced (HD1080i)?
3- At what frame rate does it deliver at full resolution? Some manufacturers will say 'up to 1080p at up to 30fps.' If you do a little digging, you will find it is either/or but not both.
4-What 'Profile' H.264 compression does it use? If you hear 'Constrained Baseline Profile' or 'Baseline Profile' expect YouTube quality video. If you need security quality video, then accept nothing less than 'Main Profile' H.264 cameras."

Mark Gally-Vice President of Marketing-VideoIQ-Bedford, Mass.