How Free and Open Source Software (FOSS) can be used to protect you and your property. Start with an old computer, add Linux, add some more open source software and you've built a system without spending anything but your time.

1. Build Your Own Surveillance System
How Free and Open Source Software Can
Protect You
Joel Avery
February 2010
© 2010 All Rights Reserved

2. Background
 Like most things, it started small
 Someone was letting their dog use my garden
as an open pit toilet
 Nearby dog owners all denied responsibility
 Why exactly people let dogs do this in
someone's flower bed is beyond me as dog can
pretty go anywhere, including easier to clean
places like pavement

3. Catch Them In The Act
 Clearly, I needed irrefutable evidence of the
dog in action and the owner in inaction
 I'm too young to just hide and wait for it to
happen
 Even then, it would be good to have (time
stamped) pictures in case things get ugly
 I needed a surveillance system, but spending
$1000 on garden defence seemed silly
 And, a fence around the front garden would be
ugly

4. Computers Are Meant to Serve Man
 As an IT consultant, it seemed that a computer
could solve this problem
 Initial investigation showed that I'd still need to
lay out cash for software if I were to do this in
Windows
 Attention then turned to an old computer upon
which I had installed Linux
 Ten minutes of investigation turned up a
software package that used consecutive
webcam stills as the basis of motion detection

5. The Garden System
 The garden monitoring system runs on a white
box system sold back in the 90s
 AMD K6 processor running at 266 MHz
 256 MB of memory
 2.5 GB of disk space
 1 USB port (no doubt USB 1.0)
 1 100 Mb/s network connection
 Minimal install of Ubuntu 9.10 Linux with an
NFS client and an SSH server for remote
access

6. The Overall System
 The system has spread to other cameras
monitoring more safety oriented locations such
as the front door
 All software and captured images are stored on
a central server on a private wired GE network
connected to the Internet at 10 Mb/s
 Remote systems capture pictures locally and
upload them to the central server for review

7. Configuration
 You can control how many pictures per second
the system shots and compares
 You can control the tolerance of change and
mask out frequently changing areas (e.g. a
road, side walk or wind blown bushes)
 You can control the amount of no activity to
define boundaries between events
 and much more
 The garden system is shooting at 3 frames per
second with 15 seconds of no activity defining
an event boundary

8. After Installation Extensions
 The pictures are grouped by events
 A couple of summary images from each event
provide a quick basis of review
 Events with a small number of images are not
summarized
 Events are rolled up by day and camera
 A central monitoring web site shows an
interesting image from the last event of each
camera as well as providing access to streams
from each camera

9. Extensions - Continued
 The summary images are uploaded to Flickr!
for review from remote locations (e.g. while on
vacation)
 As well, these images are uploaded to the free
2 GB of online storage that comes with Ubuntu
(Ubuntu One) since Flickr! has upload limits
 Regular snapshots are also taken and
uploaded (just to confirm the system is working)
 No sense allowing someone to steal your
computer which has pictures of them breaking
into your house

10. Event Review
 On the local network, the summaries of each
day's events are reviewed
 If those two images look “interesting”, the entire
event is reviewed
 The short events are only reviewed looking for
pictures of wildlife
 Review usually takes less than one minute
while drinking coffee in the morning

11. Results
 Even on the ancient computer, the system only
runs at 10 to 15 percent CPU utilization
 The 256 MB of memory and 2.5 GB of disk are
ample for Ubuntu in this deployment
 Numerous dog owners have seen pictures of
their lack of effort at cleaning up
 Lots of other animals like ducks, foxes, and
turkeys come through the property

12. For More Information
 Please leave a comment if you would like more
information or if you would like me to build you
a similar system (although I will recommend
more modern hardware)

13. Copyright Notice
 These slides Copyright in 2010 by Joel Avery
 They are not to be copied or excerpted without
permission