Hello , i have an idea about a (rotoscope) tool, but i don't know how to write a script.
Edit: sorry it's a background removal tool. Not rotoscope. I was a bit distracted when I entered the first post.
The steps I thought of:
2.clone to remove the object in layer 2
3.compare the two layers and keep different pixels, while identical pixels become "alpha" pixels
Is such a script possible?
If the the answer is yes, here are some more details:
2.1 create a path around the object (don't touch the object!)
2.2 copy the region outside the path - 10 pixels wide (this attribute should have a value box)
2.3 paste inside the path , also sizing down the pasted region, in the next 10 inches
2.4 repeat step 2.3 until the center of the zone inside the path (like a spider's web)
3.1 also the "difference" between the pixels of the two layers should have o value box - for the objects that have similar colors to the background
3.2 another tool would be to subtract the color in the cloned layer , from the original layer, and thus create levels of transparency in the cutout object (for trees, hair, reflections on glass or water, fog/smoke etc)
3.3 a really fun tool would be this: make the spider web from 2.4 visible and allow the user to choose between 3.1 and 3.2 before applying step 3 all together
Maybe by using some sharpen or blur effect before or after step 3 would give more options to the definition of the edges of the final mask.
In conclusion , having all this steps in one tool wold not only make GIMP more user friendly for beginners, but it would help thousands of cg studio employees in developing countries . But that's just my opinion.