Transform Cellphones Into a CCTV Swarm

holy_calamity writes "Swiss researchers have developed java software that has bluetooth-capable camera phones form a distributed camera network. Each phone shares information on visual events with its neighbours and can work out the spatial position of phones around it (pdf). The software will become open source sometime next year, and the creators say it could be used to make a quick and dirty surveillance system. 'The phones currently use the average speed people walk to guess the distances between themselves, based on how long people take to move from one phone's view to another's. In testing, the system determined the distances between each phone with about 95% accuracy. They were placed 4 metres apart, making it accurate to about 20 centimetres. In future, recording the speed at which objects pass by would make more accurate judgments possible.'"

I predict

[Buelldozer]

That the police are going to really dislike this.

Little Brother?

[Anonymous Coward]

So if you have a huge surveillance system that isn't controlled by anyone, is that the opposite of Big Brother?

Analyze the average quantity of pocket lint?

[kevmatic]

Most people I know don't keep their cell phones in some snap-off carrier on their belt like a modern-geek pocket protector. They stay in pockets, where they can't see. And women keep them in purses. So only a few phones are actually going to be able to see without their owners holding them out on purpose.

What's the point of this, again?

Re:concert-recording on the cheap

[evanbd]

The problem with this approach is that audio ADCs have an analog antialiasing filter in front of them. It's not just that you can't see the high frequencies because you don't have enough samples; they're actually *removed* from the analog signal before it's digitized. If they weren't, you could recover them with enough microphones, but you'd also get weird aliasing artifacts. As it is, they're gone, never to return.