Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror

Comment Re:Don't bother with motion cues for exterior (Score 1) 508

I do a lot of work with the Axis cameras, although almost always running my own algorithms on their video. They're nice hardware to work with, but I don't think their algorithms perform all that well (and if I'm not mistaken, they're another example of "ObjectVideo Inside", so it's not really their algorithms). Of course, designing better algorithms for the motion detection and what not is part of how I pay my bills, so YMMV.

Comment Re:Don't bother with motion cues for exterior (Score 1) 508

"... then you're not doing it right" pretty much summarizes (to the best of my knowledge) state-of-the-art when handling exterior conditions with purely visual sensors, particularly when you're relying on crappy source video with no algorithm-in-the-loop auto-iris control (or worse: analog auto-iris) and god only knows how many layers of crappy A2D, D2A, quantization, etc. steps in between. You need other motion sensors that give you more reliable cues, but even with clever placement, you are always going to face a fundamental trade-off between probability of detect and probability of false alarm.

As for motion sensors + dogs, what is stopping them from aiming the detectors to have a deadzone that ends ~3-4ft off the ground?

Comment Don't bother with motion cues for exterior (Score 1) 508

You'll discover very quickly that using motion cues to trigger anything other than a light outside is either going to generate a bazillion false alarms or basically be so insensitive as to miss everything. In my opinion, your best bet is to setup two zones: the exterior zone and the interior zone. For the exterior zone, several fake cameras (really just camera-shaped pieces of plastic with a blinking light) plus a few otherwise indistinguishable real ones plus DVR can be had for pretty cheap (Costco, for instance, has kits as low as $250ish). You can use either the built-in motion detection or cue from an external unit (haven't done this myself but I expect it to be pretty straightforward based on how I've triggered similar systems in the past). Key piece: make sure that the storage ends up being put somewhere reasonably secure, away from the DVR and things that look like they're worth stealing.

For the interior zone, I'd use same trick(s) except this time you want to trigger off window opening / door opening sensors as well as motion sensors. The hard part will be to make sure you match up to consistently. I'd want a hysteresis threshold (after x seconds of consistent motion, send a snapshot, after an additional y seconds turn on the sirens).

All in all, it's pretty straight-forward but it's likely to be time consuming, which leads me to: are you sure that what you need is a security system to re-establish your sense of security?

Australia

Submission + - Increased safe harbour laws for Aus? (ag.gov.au)

WizRd writes: The Australian Attorney-General's department is calling for submissions to extend the current safe harbour Copyright Act to include educational institutions, work places, or online services such as search engines. Currently only carriage service provides are protected.
The Internet

Submission + - Continuing the Distributed DNS system (activepolitic.com)

bs0d3 writes: Last year, piratebay co-founder Peter Sunde gathered coders to begin a decentralized dns system. This is a direct result of the increasing control which the US government has over ICANN. The project is called P2P-DNS and according to the project's wiki, this is how the project is described: 'P2P-DNS is a community project that will free internet users from imperial control of DNS by ICANN. In order to prevent unjust prosecution or denial of service, P2P-DNS will operate as a distributed and less centralized service hosted by the users of DNS.

Today the project continues, barely. A majority of interest shifted to namecoin once the idea was realized, but coder Caleb James DeLisle continues on the first project. So far he has dht nodes and routers worked out, and awaits help on his irc channel whenever volunteers are willing to join.

Comment have you considered a rc hobby kit? (Score 1) 232

they are surprisingly inexpensive ($500 plus some labor w/ analog video downlink). they are also likely to have been repaired quite frequently (that is if you're lucky and didn't leave a pile of kindle your last encounter with gravity).

on an unrelated note, it's fun to watch confirmation bias in the wild.

Slashdot Top Deals

(1) Never draw what you can copy. (2) Never copy what you can trace. (3) Never trace what you can cut out and paste down.

Working...