Have you ever received a really awful scan of some text that was saved out using JPG compression? If you zoom in, you can see speckles around the text, making it fuzzy and hard to read:
I exaggerated the artifacts to make it more clear. Here’s what I did to clean things up.
First, I rotated the canvas to de-skew the scan to ensure the text was straight. You can use a horizontal guide to align.
Next, I reduced the brightness -10% and increased the contrast by 20%. This worked well for me, but you should play around with these settings while zoomed in so you can see what works best for you. It’s a balancing act trying to remove all of the noise while preserving the anti-aliased details of the text.
Next, I desaturated the whole image, which eliminates any color artifacts present. You can see patches of cyan in the screen grab above. And finally, I export at a PNG, a file format that works great for text.
Here is that same text cleaned up: