How can I reconstruct final image by using Gbuffer captured by HighResolutionScreenShot?

Hello guys.

To tune color after capturing image, I would like to use composite soft such as “Nuke” or “Maya Composite”.

I find the method to get Gbuffer, HighResolutionScreenShot.

But I could not find how to get the same image with captured one by combining GBuffer.

Did anyone know how to calculate final color by GBuffer?