In the spirit of sharing, cuz I think this is a great script (thank you), I prefer using maim over scrot simply because it has a --nodrag option. Personally feels better when making selections from a trackpad. Click once, move cursor, click again.
I was using something like this for awhile, but I found tesseract did poorly quite often. That resize trick didn't seem to affect much. I'm not sure what pre-processing would make it better.
I'd love to if TextSnatcher does anything to improve on this. The github page is opaque.
Having used Tesseract for OCR for other things, getting the right PSM helps but it's still rather terrible, especially for sans-serif fonts, which are common in UIs.
Granted there's a lot of ambiguity in sans serif fonts, lower-case "L", vertical bar, and upper-case "i" can even be pixel-identical, but I've seen tesseract turn
Chapter III
into
Chapter |l1
which really surprises me. In fact, for books, I run it through sed to replace vertical bar with upper-case "i" and it significantly improved recognition.