I used to get rid of noise in my scanned photocopies using a mixture of Brightness and Contrast which worked quite well. Then I found a better method by increasing the Exposure and Black Levels which worked even better. But there are still times where I can't completely remove all of it without needing to manually erase it like in the below example:
Increasing the Exposure and Black Levels will still give a cleaner result but I would still have to manually remove it:
Is this currenty the best method possible or is there a feature in Gimp that can get rid of this type of Noise? It is likely that AI is the only solution, are there any free AI tools that I can use to do this?