I scan at1 TIF 600dpi at greyscale in my scanner OpticBook 3600
as you can see in this screenshot, the scanner somehow produces images with some marks, I don't know if glossy paper is responsible for this (the marks look like reflections) or the scanner or something else
this is the crop of a scanned page:
this is the same crop but with lowered brightness and contrast in photoshop:
the characters have marks around them and these can cause problems to the Finereader 9 and spot them as 'uncertain characters'
do you know what causes this?
I also wonder if there is a way to fix this