Reflective Tape looks white with Green LED

[CJay]

We have the green LED ring around our camera, but the reflective tape looks pretty much white in the image that the camera is giving to the driverstation, we are not really sure what is going on and any advice/suggestions are appreciated!

[DonRotolo]

I am not programmer, but maybe this might help:

Perhaps the image is so bright, the color is washing out. It is a color camera, right? In normal light, do colors look normal? If so, that's the issue.

Otherwise, there may be some kind of calibration that tells the camera to display green as white and everything else as non-white??

[MikeE]

Originally Posted by CJay

We have the green LED ring around our camera, but the reflective tape looks pretty much white in the image that the camera is giving to the driverstation, we are not really sure what is going on and any advice/suggestions are appreciated!

I'll assume you are using the Axis camera from a previous year's KoP.

Reflective tape returns a substantial proportion of the source light so under many conditions it causes saturation of the image. In this context saturation means that the signals representing the components of the image are limited. For example with green LED illumination the signal from the green sensor could hit the maximum limit of the camera sensor and be capped while the blue & red signals are much lower and are not limited. That would result in the final appearing less green. In extreme cases all three signals hit the limit so the image appears white.

There are a couple of tricks to avoid saturation: decreasing the brightness and setting a fast exposure.
Happily the procedure for both of these tasks for the Axis camera was described in the Vision Processing section of the 2013 WPIlib documentation. The whole document is well worth reading, but for your specific question check the section on Exposure towards the bottom of the Camera Settings page.

[Al Skierkiewicz]

To prevent extreme video, cameras employ a circuit called "white clip". You can think of it as a hard ceiling that the video cannot exceed. When you have enough light to hit the clip on all three colors, it will show white. The LED ring is not narrow band green but does have emission in other colors.