A Ceiling for Megapixel Surveillance?

How many megapixels do you need?

I got a note from the UK version of the IP UserGroup this morning promoting one of their clients that will be at IFSEC next week. The company, SentryScope, apparently has a 21 megapixel camera. If you want a sense of how high or a resolution that is, then consider this -- if you record at their highest level, you could eat up 100 Gigabytes of storage a day doing continuous recording. The camera's image is a black-and-white panorama with an aspect ratio of 5:1. This is basically what you'd see (you can zoom in of course, because there's plenty of data detail):
SentryScope example

So I'm sitting here thinking about when you really need that much detail. Obviously, as one of our columnists wrote earlier this year, these kind of cameras are great if you want to catch license plate data.

But parking lots are only one aspect of security. I'm thinking back to a recent visit with the security staff at a hockey arena in South Florida and thinking how it could have been set up with a camera at each end of the venue that could give you great situational awareness, as if you were standing in a nosebleed balcony with a nice set of binoculars in your hands -- instead of where you really are -- in the basement, in a cinderblock room watching cameras.

The fact that you can get 21 megapixels (it's higher than most color cameras because you can get higher resolution if you ditch the color pixel capture on the image sensor) makes me wonder where the megapixel push will end up. Scary as it is to those who have to consider compression and bandwidth, I've heard rumors of Gigapixel technology for surveillance cameras. (You can kiss your 250Gb hard drives away if that happens!)

If you remember back to the advent of consumer (still) cameras, they started at .5 megapixels and then progressed such that most consumer cameras seem to be delivering between 4 and 6 megapixels. They certainly can go higher, but this seems to be the place where the need stops. At that size, you can shoot a full-resolution 8x10 image, but it's still small enough to not fill your hard drive up too fast.

I think we're still trying to find that point in the super-high-resolution/megapixel surveillance camera business. Sure with correct lenses, these new cameras can read your license plate from 150 feet away, but there's a point at which image stabilization issues come into play. And if we built a big enough sensor, we could probably capture 200 megapixels (if we could handle the data processing -- which would probably need its own dedicated PC running with the sensor). But we're having to define what it is we need.

Those of you who have integrated these super-high-res systems, and those who are manufacturing/selling them, feel free to write in and let me know if you think there will be a virtual ceiling on how high of resolution we will need to go.