Texture and face

I have my own 2D face image and 3D OpenGL face model with triangle polygon mesh(I also have all the vertex coordinate).
How can I map my face texture on 3D model?
I wonder if I have to segment my face image to every pieces of triangle mesh and map each piece on every mesh in 3D model.

if I have to do that, in my opinion, this operation will take too much times.

Plz~~ tell me how to map 2D face texture on 3D model
thank you for your time…^^

You would noramlly have ‘skin’ the model in a package like 3ds or milkshake- you leave the texture as it is and use various tools to map the triangles onto the texture so each triangle gets its part of the texture. It is very time consuming and difficult etc. If your modle doesn’t have any texture coordinates then you will either have to do the above or you could try doing planar mapping or some such method but it wont look good.
-> the model should have texture coordinates, if not what is the model format?