This may be trivial, but I cannot figure out how to do it: I'm looking for a way (preferably in gimp or another open source application / plugin - I also have a rather old photoshop version) to remove the background of an image when you have the full original image, so i.e if I have this composition:
and also this image
How can I remove the background and leave the objects alone like this, without having to trace the borders using selection tools / magic wand? that is, like using the background as a green screen
Just to clarify: the images will always be composed digital lossless files, so no difference on ilumination, compression artifacts, focus etc.
Also I'm looking for a solution that works whith complex objects like the feather, hair, a grid, etc... not easily traceable with selection tools. Already tried the method of substracting one image from another, but doesn't give very good results.