Autoconfiguration with OpenCV

One of the main configuration aspects of a PiWall video wall is the geometry file.   This maps each tile in the wall to the coordinates of the video it should render.   For small (2×2, 3×3) walls, it is practical to simply take measurements, either from the wall physically or from a photo.

We are currently collaborating on a project which will have around 300 screens, and so it seems worthwhile to invest in making a tool to handle the geometry definition automatically.

A proof of concept prototype in OpenCV can be seen in the following video where a phone is pointed at the wall and rotated to give a series of images of walls at different angles.   The OpenCV processor takes each frame, applies rectangle image identification and overlay, and then generates a video of the combined output.   The algorithm needs some refinement and we have ideas for how to inject patterns that will help with the task.


Kickstarters we’ve backed

We’re Kickstarter fans, and one of these days we may well get around to launching our own project – perhaps a Pi Cluster case, maybe some cuskickstarter-icon-squaretom electronics.   In the meantime, we like to back other innovative projects, to get our hands on interesting devices and to follow the progress and learn how to kickstart (or how not to).   Here are some of the projects we’ve backed.   Future posts will give feedback on what we’ve done with the devices.

  • Pine64 (received May 2016) – Pi3 like board but with Gb ethernet.


  • PiWalls : projects based around PiWall
    • Eaux Claires Festival 2015
    • 1983 Ltd Art Installation Collaboration (just started)
  • PiWall Pro : tools and enhanced PiWall Features
  • PiWall :  raspberry pi based video wall solution
    • Initial development for CCFE PR system
    • Public domain release (as seen on Hackaday, Pi Foundation)
    • Canadian City Project
    • NASA student project