Dent detection after hail

Question

The next photo is a photo of hail damage on a car, taken with a rubber projection.

I want to detect dents and classify them (large in yellow and small red).

How can i do this? What algorithm / method do you suggest?

Answer 1

Dilution is a good idea, but you really don't need it if you can binarize: blob contours will produce equally good curves.

Follow each curve in turn and evaluate the curvature, for example, by determining the deviation from the line segment between two points fifty pixels from each other.

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