cleaning a scan of music

[rich2005]

(11-24-2021, 08:57 AM)warrentdo Wrote: The grow by 1 delete seems to be ok, but it removes 1 of everything so not 100%.

Since it is a 1 bit image - just black and white pixels, a grow by 1 / BG fill de-selects single pixels then a shrink by 1 / FG fill restores the body of the image. Any spots remaining, repeat the process.
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Otherwise
I would be inclined to convert to RGB and use something like the gimp_gmic_qt plugin which has a clean scan filter.