[Greg McKaskle]

There should be a white paper on the NI site, but I haven't been able to find where they put it. Fortunately, Brad also posted it to FirstForge in the Documents sections. It is called 2012 Vision White Paper.

First off, yes, it is retroreflective tape, micro-sphere based, and quite bright. That means that if you use a ring-light, your camera will receive a rather isolated source of light that you control. The FIRST field is a pretty harsh and chaotic arena for vision experiments, but the end of the field where the drivers stand is not harshly lit or the drivers would be staring into the lights. Clearly many frequencies work with retro-reflection, but I'm not sure about its response across the spectrum including IR. Additionally, while it is possible and pretty easy to replace the lens in the Axis 206, the M1011 is an integrated lens. As a bonus, it is rather hard to see IR, therefore, harder to troubleshoot, inspect, and debug. So, my suggestion would be to go with team colors in the form of an LED ring-light. Or go with small LED flashlights on either side of the camera.

The example code that ships with LV doesn't attempt to compute angle information, but does include distance calculations. The code includes a color mask and a brightness mask with an optional Open operation and everything else is done with binary particles. The paper also discusses edge approaches.

One final wrinkle to throw into the mix is that there are enough communication paths to be able to do some/all of the vision processing on the laptop and send information back to the robot.

Greg McKaskle