Modeling some Ironwork

Hello all

I've frequented these forums a little in the past, however this is my first post.  I'm currently trying to reproduce some of the iron work from Hector Guimard's entrances to the Paris metro system.  

As you can see it's a bit complex.  I'm looking to maintain as much detail as possible.  I have tried to create a Heightfield from the image, which produced a pretty great surface, unfortunately it was too complex of a surface to be broken down or manipulated(rhino would run out of memory trying to do anything with it).  I know that grasshopper also has image interpretation, and I was wondering if anyone had any advice in what the best way to go about modeling this would be.  It does not need to be grasshopper per se, it could be standard rhino tools, but I would be grateful for any advice anyone has on this topic. Thanks.