How to export a model texture to png or jpg?

Hi.

Can anybody help me?

I have a model exported from blender and until now I can barely move, scale and rotate the texture (with uvScale, uvOffset, uvAng)but what I need to know is how can I do a function to export the modified texture (after moving, scaling and rotating) to jpg or png?

If you know where I can find a live example you'll be my god

Thank you all.