[Greg McKaskle]

The ambient lighting shouldn't be that much of an issue.

That is based on the fact that these markers are in roughly the same place and at roughly the same orientation as the circles of last year, and that part of the field doesn't catch much glare. It is bright, but the lights are coming from the long sides of the field.

The second reason is that the material specs claim it as 600X brightness for narrow angles. This means it reflects 600 times as much light back to the source as a white painted surface would. I'm sure the measurement specifics are much more technical than that, but it is very bright. Meanwhile, the ambient light or other spots will be returned to their sources. If they aren't right behind you, you should get a pretty pure reflection of your source.

The lights used in the tutorial were cheap christmas lights, not too bright, and they were acceptable even with windows behind the targets. Depending on your light source color, I would experiment with the white balance and try to set the image exposure similar to how it was for 06. In other words, darken the image to where not much more than the reflected lights and active lights show up in the image. You may be able to do this with the auto exposure and brightness combo, but I believe that it will be best to use a custom exposure that results in markers being high intensity and high saturation. This will also speed the threshold processing since the luminance and saturation will then exclude more pixels before the hue is even calculated.

As for using IR or a single color plane, I'm interested to hear how it works. The sensors should be sensitive there. You may need to replace or modify the lens, and if I remember correctly, the IR source will show up more as a white light and not a colored light.

Greg McKaskle