How to merge two hand perspectives? Using 123D catch (creates 3d models from picures) I created two mesh obj of an hand in dorsal perspective (palm down), and another in the palmar perspective (palm up). I'm trying to come up with procedure to merge them together and create a whole hand model. 

I had a look at stiching UVs but it seems that I need the same number of vertices in both hands meshes. Bolean operations seem a reasonable option but the result requires some further modelling I don't have much experience. 

Any insights to this project would be much appreciated. E.g. Which prodecure is best bolean vs. stiching, how to change vertices at boundary loop to the same number in both meshes. Or any other aspect for this. Scripting advice for these would also bee nice. I.e. what kind treatment do I need to give meshes to create a script for this.

Kind Regards,
Miguel

edit:picture of the hands added if more clarification needed let me know. This is a rough model based on a old picture I have of my own hands
I would just go for some retopo scheme.  If you overlap and align them both you can then build up a new mesh using conventional methods for generating clean meshes from ones that are not so clean.  

The problem you are facing is very similar to the issues facing Dynatopo sculpts so the solutions you have are pretty much the same as well.

Once they are aligned properly with each other, you can select them both and merge them into one object, Ctrl-J.  Next you can use the CG Cookie Contours tool to rough out most of the new mesh that will be based on these two as one base.

There are also other methods that you can employ without using Contours.  You can just start with a point in edit mode and extrude it out along the surface of the scanned models and by using the Magnet tool you can keep the points moving along the surface of the base mesh.  

Also, if you model a low-poly, rough hand shaped model, you can use the Shrink Wrap modifier to project the new mesh onto the scanned models.