Quote:
Originally Posted by Jared341
Here is the strategy that has worked for 341 using an Axis camera and LED ring(s). We never had to calibrate on the field in either 2012 or 2013 (both years, all of our shots were aimed by our vision system):
1. Turn off automatic white balance on the camera (can be done from the camera's web interface).
2. Get a very short exposure time so the image is mostly dark (from the web interface). You want a very dark image, except for the illuminated regions of the reflective tape. Set the exposure time to something very short. Put the camera in a bright scene (e.g. hold up a white card a foot or two in front of the lens) and then do a "hold" on exposure priority. Experiment with different settings. You want virtually all black except for a very bright reflection off of the tape. This is for two purposes: 1) it makes vision processing much easier (fewer false detections), 2) it conserves bandwidth, since dark areas of the image are very compact after JPEG compression. The camera doesn't know what you are looking for, so it will try to send you the entire scene as well as it can. But if it can't see the "background" very well, you are "tricking" the camera into only giving you the part you need!
3. Take a wide variety of sample images in and around our build space.
4. Design a threshold in RGB or HSL that works well on your sample images.
5. Your camera is now effectively much more sensitive to your LED ring than to ambient lighting, and all dynamic settings on the camera (white balance and exposure) are held constant. You likely will not need to do calibration (but of course YMMV).
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Thanks! that helped a lot and I'll be making sure we follow your instructions
Quote:
Originally Posted by topgun
Make sure your drivers tell you about the time available. In 2012 we kept waiting for the announcement to say the field was open for vision testing. Never heard that announcement so I asked the Field Supervisor. Turns out the announcement was made at the Drivers meeting. The drive team didn't seem to think they needed to relay that information to the programming team. That hurt our efforts with vision, and ultimately our matches. I didn't let the drive team forget that too soon.  |
Sorry for you guys, I hope you'll have it better this year. That's the first thing I'll tell our drivers (if we would finally choose them..
)