I have an image rendered, and its showing in the Blender Render window. In the compositior, i have a file output node set up to write out .tif files for each render pass. Can i somehow execute just the node tree without having to re-render my image?
Ok, so the proposed answer said: "Delete the renderlayer node from the node setup, and then blender won't render the 3D scene."
Feeling stupid here, but, if i remove the renderlayer node, then my file output node won't have any inputs anymore. It's direclty connected to the passes of the renderlayer node to output each pass as a .tif file. Secondly, what button do i have to press to then execute only the compositor nodes??