Gas consumption in Paralelni Polis Gas reading with SimpleCV and Scikit


Paralelni Polis is three storey building with no insulation whatsoever. Our gas consumption is so big, that last year our gas bill reached the sky, and we got disconnected. This is the reason why we need keep an eye on our gas usage.

How does it work

Camera board has normal USB webcam glued on the front side with few LEDs to light up the scene. Flexible camera stand is used to adjust camera view.

This is how board looks like from the back. On the left side you can see Odroid, WiFi dongle and USB memory stick. That's where SimpleCV does its magic. In bottom corner sits voltage regulator which makes 5V out of 12V for Odroid. And a lot of LEDs. Just to make the back cover look pretty.

And that's how everything looks in place. Camera is positioned slightly above the gas meter, to prevent reflections from LEDs. Back cover was designed and printed by MakersLab is light up by many LEDs you can see on previous the image.

This is image taken by the camera. That's where computer vision fun begins. In corners you can see orange stickers which helps us to find the counter, area we are interested in.

We just look for orange blobs desired size. It's easy to find our stickers on the image.

Knowing where the corners are, we can resize the counter to a rectangle of known size.

Now we know that our digits are in particular location of the image.

With a little bit of magic, we can crop digits from the image. Digits are roughly 50x150px big and similar to MINST dataset. Digits recognition uses LinearSVC from Scikit.

This was my first project with SimpleCV and I fell in love with this library. Its API is really simple and easy to use and you don't need to have ten PhDs to understand it.
I tried to document the code as much as possible, feel free to use it for whatever you want.

Fork me on GitHub

About Paralelni Polis

Paralelni Polis - Institute of crypto anarchy is non-profit organisation in Prague, Czech Republic. Every year we hold Hacker congress, we implant NFC chips into our bodies and organise a lot of interesting events, which you can find out more on our Facebook page.

Bitcoin Coffee is the first Bitcoin-only espresso bar in the world. A coffee laboratory aimed at achieving a superior taste in every cup. It is a meeting point, where there are no borders between customers and stuff.

Paper Hub is unique coworking space built for innovators, startups, students, digital nomads and hackers allowing them to work on their prototypes, experiments and projects. It offers innovative and creative working environment in the open space furnished with honeycomb paper furniture, offices with fixed desks, spacious terrace and meeting room.