Deformed edges on object by Bump/Displacement - How to?

[JakubCech]

Lets say I want to create a curb like this

Where only edges are heavily deformed. Deform edges script is not sufficient for such detail and I do not want to spend time in zbrush or do any complicated stuff. I would love to use bump/displacement for this by using some map I already have but map is applied on whole object - how can I limit the map to be smoothly applied on edges only? As far as I tried, CoronaAO, RoundEdges and Wire does not work in Bump/Displacement slot.
Thank you for suggestions.
Jakub

[maru]

My first guess is using vertex paint as the mask for the displacement. I think there was a script which automatically baked vertex colors based on AO, but I cannot find it. You can also paint the vertices manually if that's not a very complex object.