when scanning a document, there is one thing that is HIGHLY unlikely to happen...
to produce perfect black pixels. these are pixels whose rgb value is 0,0,0
it’s near impossible as the CCD camera picks up the shades of grey... which produces the very appealing effect as you zoom out.
if you look at this ‘document’ you’ll find many perfect black pixel areas.
it just doesn’t happen with a scanner... only a pixel painter (ie: photoshop)
But post-scan processing can change text to perfect black for file compression purposes. Google "mixed raster compression"--one of the patent-holders has said the BC anomalies look like the result of that.