Frame Preprocessing for Against the Light and Aruco Detection

Python
1

I’m trying to detect an Aruco marker from outdoor. The goal is to detect the aruco at 3 meter distance.
My only problem is that the marker is undetectable because it is ‘against the light’
I have a preprocessing algorithm that I can adjust the image’s brightness based on a certain gamma. However, it does not work. Is there any way to do a preprocessing that can detect my aruco marker in the stated condition?

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Thanks!

2

either use a ring light around the camera and retroreflective target surface (for the white parts), or make the marker a stencil that has holes to let the backlight through, but you’d have to hide at least the “bridge” that holds the entire marker because the outer border must not be interfered with (quiet zone = bright, etc)

or adjust exposure manually, or use some other knowledge of scene illumination to adjust it.