Detection of Circular Aluminum Disk on Grass
Chris G from United States  [1 posts]
12 year
We are trying to detect a 3-inch diameter aluminum disk using various circle and blob detection algorithms on roborealm. Currently we are a bit stumped as to how to effectively detect it in a variety of lighting situations.

The object is to be detected on a variety of surfaces such as grass, concrete and dirt. If you look at , and the disk looks almost white. Compare this with (and to a lesser extent ) where the disk looks gray. Figuring out a solution to detecting this object is difficult and I was wondering if anyone had any suggestions to go about solving this issue. Any input is appreciated!


John Wood from United Kingdom  [67 posts] 12 year
Hi Chris.
I am working on a similar usage unfortunately my shapes (boats) vari in angle and shape.
Here though is what I ended up as my starting point which may help you as a guide to go forward from here.
I have tried it on your disc photos and seems to work OK though other factors may be present in the real world.
Good luck
Anonymous 12 year

What you really want is an elliptical detector ... when you have a circle on the ground taken at an angle it becomes more of an ellipse.

You need to focus on the shape and not on the color ... as is obvious from the image where the circle appears gray.

See attached as a start. Do you know the position of the camera wrt the disk? This is assumed in the perspective module that undoes this distortion. If you are not aware of this angle other techniques will need to be used to correct for the affine view.


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