From what I see
1. make a duplicate of scan layer
2. use rectangle select to isolate the handwriting
3. If lucky, fuzzy select might pick it perfectly
4. Then try level or curves under Colour
You might get more ideas if you can spare some time so that other can answer. Meanwhile, I think the steps I mentioned might be of help.
1. make a duplicate of scan layer
2. use rectangle select to isolate the handwriting
3. If lucky, fuzzy select might pick it perfectly
4. Then try level or curves under Colour
You might get more ideas if you can spare some time so that other can answer. Meanwhile, I think the steps I mentioned might be of help.