Cracks segmentation

[kirill8910]

Hello!

I'm trying to make segmentation of the cracks (picture) as precise as possible. Of course grains on the background make it tricky. These tiny cracks have at least sharp slope in the intensity change (plot profile).

Could you suggest me any labeling or threshold plugins where I can set this kind of criteria for the segmentation. Or is it an algorithm for that...

Thank you!