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Backlit Aruco Markers

asked 2018-05-03 02:35:17 -0600

jordan314 gravatar image

Hi! I'm building a robot and I'm trying to have it follow an aruco marker. The problem is that it's often backlit so the camera can't see it at all.
C:\fakepath\Screen Shot 2018-05-03 at 12.25.07 AM.jpg
I had the idea of using a phone to display the marker so that it was lit better. But actually the paper marker works better. The camera seems to distort the corners and edges of the marker as seen below.
C:\fakepath\Screen Shot 2018-05-03 at 12.24.30 AM.jpg
I'm going to try a better camera, but does anyone have any ideas on how to fix this? I'm also trying to make my own 3D printed mask and white light, but am worried the same problem will occur. (Also I'll need to paint this black). C:\fakepath\IMG_2983.JPG
I'm also having problems with motion blur when the robot moves, if anyone has any suggestions.
Thanks, Jordan

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  1. If you are using automatic exposure control, you may need to turn that off to control the shutter speed and/or gain manually on the camera, so that you can expose the aruco target for optimal contrast.
  2. I'm not sure why you see distortion on the phone image.
  3. To reduce motion blur, reduce shutter open time; this may require increasing camera gain, ISO, aperture, or adding illumination.
opalmirror gravatar imageopalmirror ( 2018-05-03 16:27:36 -0600 )edit

Thank you for the feedback! Will try those.

jordan314 gravatar imagejordan314 ( 2018-05-04 13:30:13 -0600 )edit

Do let us know how it turns out here in the comment thread. If you find the answer, please post it in the answers below. If you don't but can improve your question, please do so above. Good luck!

opalmirror gravatar imageopalmirror ( 2018-05-04 13:42:17 -0600 )edit

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answered 2018-05-14 03:15:40 -0600

jordan314 gravatar image

updated 2018-05-14 03:16:18 -0600

I'm still working on the motion blur and haven't tried adjusting the exposure yet, but as for the marker being backlit, I bought a backlight and tried making my own 3D printed marker. It works better!
image description At first it wasn't working until I realized the markers seem to work better with a white border in addition to the black border. So I taped a paper border around it and it works. Also if I put a white border on the marker on my phone, it works on my phone too.
Thanks again for the help!

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Asked: 2018-05-03 02:35:17 -0600

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Last updated: May 14 '18