Is it possible to modify the texture by "unrendering"?

[Goldname]

Given a 3D model, I'm hoping to be able to render it, modify the rendered image, then "unrender" or "paste" the image along with the modifications back to the 3D model. Is this possible?

[pbourke]

It is possible to project an image (your rendering) onto a 3D model. Except, in general the rendered image does not contain enough texture information, so when projected onto the model there will be parts untextured ... specifically those not visible from the rendering camera position.

[Goldname]

Thanks for the response. I plan to start with a fully textured 3D model. With this, I plan to modify the texture by modifying a rendered portion of it. Do you know any method to do this in python?