When ever we take a frame of the green light with our new CMU2 camera we have a problem. The green light appears as teh same pixel color as the overhead lights above (white).
I have attached a frame.
If anyone knows what is going on their help is much appreciated.
You probably just need to turn down the brightness
Use YCrCb instead of RGB Colors and turn off Automatic Gain Control.
You have accidently discovered that fluorescent light changes color at a 120Hz rate. Part of the time it is green and part of the time it is blue. Your eye integrates the color flicker into a single color since your eye can only see this motion at less than 24 times a second. Correcting for white balance or using some of the other techniques discussed in the documentation will help.
We have the same problem with our camera. We work in the autoshop so it hits the overhead shoplights and locks onto them. We fixed the problem artificially by making the tilt not go as high as the overhead lights
See this post and thread for a possible solution to try:
Ethulin, that is exactly the kind of picture we got this morning after completing the build of our target light. This is with a brand new 2007 camera.
The target showed up as 240,240,240. So did the non-reflective calendar on the wall. So did the flourescent lights in the next room. We tried using the adjustments mentioned in the LabView manual but those did not help at all. We also tried adjusting several different values in LabView with no luck. I had to leave before we could spend more time on it.
I have searched several threads and have not found any actual working values posted.
EDIT: I just noticed that Kevin Watson’s page contains a workbook with complete calibration procedures. Looks like I need to do some reading.
That’s what it looks like in RGB values. Switch to the YCrCb color space and you’ll find it looks very different from nearly everything else the camera might see.
You shouldn’t need to do any calibration. Please see the FAQ for details: http://kevin.org/frc/camera.
-Kevin
Well it was strange, but we did have to calibrate ours to get it to work. Not much though, but still…
We’ve tried the default “bells and whistles” code both with and without calibration, and no such luck. We can achieve a constant tracking confidence in labview of over 200, but we transfer these settings through the camera menu, it can’t find the target at all. Without any calibration, we can’t find the light either, even though all the documentation says we should be able to.
We’re in a fluorescent-lit shop, but the target is convieniently located in between some shop lights. We’ve tried Eldarion’s tips with saturation AND darkening/diffusion filters, but these haven’t worked when running through the RC either. They work great through Labview though.
If it helps at all, the lights are a full pink in Labview, and the light is barely different
I’m just about ready to give up on the camera…
Too bad I need it for the AI-controlled driving we were planning on making…
The programmers on team 11 did change some of the values from default. We lowered the saturation and brightness, along with tweaking some other values.
Kevin’s code did work, but when we started working in a room with bright flourescent lights the camera picked them up too.
Now we basically when we take a picture in labview, we see a black screen and nothing is highlighted other than the green light.
…and make sure you’re in YCRCB not RGB.
We’re out on the shop floor as well. Using Kevin’s default camera code, and experiencing the exact same thing.
First, let me say “Thanks Kevin!!!”. Without your code, we never would have even touched the camera. (Or the encoders… or the gyro…) Our lack of dedicated “controls” guys makes things very tough at times.
Anyway - our rack is made out of 2x4’s and PVC. The overhead lights are sodiums. Our camera with the default code is picking up the green light, the reflections of the overhead lights off the 2x4’s, and the overhead lights as well.
I’m going to spend sometime with labview to see if I can tweak it away from that. It is making our whole team very very nervous. We know the play areas are VERY brightly lit, and with the end plates on the racks being diamond plate - we’re worried that we’re going to get a lot of very nasty reflections when you’re facing the target.
I agree you need to make sure to be in YCRCB and not RGB