Federico Lucifredi wrote: > I am wondering if anyone has played with motion-activated cameras, > for security use or for child monitoring.
Software or hardware-based motion detection? I have tried out the software-based motion detection built-in to a variety of Linux-running IP cameras. They all performed lousy. Typically they'll trigger when lighting conditions change (i.e. cloud passes in front of the sun), so unless you have a purely artificially lit area, you'll have problems. Reduce the sensitivity to avoid these problems and you'll miss legitimate motion. To solve this I ended up wiring up a traditional hardware passive IR motion detector to my cameras. A number of inexpensive cameras have external trigger inputs which you can use to trigger emails (or whatever) just as if the internal motion detector fired. Way more reliable. Panasonic's IP cameras, which are a bit dated now, were notable for having built-in passive IR motion detection hardware. Given how little cost this would add to the camera (maybe $2 or $3), it's hard to see why all cameras don't do likewise. ACTi has some more modern (megapixel resolution) cameras with built-in PIRs, like: http://www.acti.com/product/product_info.asp?PID=F633BFB5-A26E-41C9-BFD5-FB307E987659 but (so I've read) they took a common boneheaded approach of putting a web UI on their Linux-running camera that only works with IE (about 2 web browsers behind current trends). I hear that the motion detection software in ZoneMinder is decent, but haven't personally experienced that. I imagine if you are using beefy enough image processing hardware on a central server that you can make software-based motion detection work well. Personally I like the idea of offloading processing to the individual cameras so you can scale up to multiple cameras without needing to upgrade the central server. -Tom _______________________________________________ Hardwarehacking mailing list [email protected] http://lists.blu.org/mailman/listinfo/hardwarehacking
