[Extracting Geometry using a alpha map]

HI Guys, I'm trying to do a little project and was wondering if you guys have any tips or ideas on how i could extract geometry from an object using an alpha map.

For example say a Ming Vase, how could i seperate the geometry of the white bits and the blue bits?

I found a tutorial on zbrush,

but i'm hopeless in zbrush.

Any ideas if you can do this sort of thing using 3dmax, rhino, meshmixer, fusion360 etc?