@Zistmo I agree that Eink and scanned pdf equals philosophic reading

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As a Kobo Aura HD user I am starting to be quite happy with reading scanned pdf's in koreader.
There are some shortcomings (dictionary and notes are not really working perfectly.) And seeing your picture in #7 I do wonder whether setting the text to "darkest" or high quality with reflow will give a good result. Question is whether you should blame the reader (device/koreader)?
Blame the scan. I do. I use Scantailor to make the texts really black&white again. (I can't find the beta-version I am using anymore online, so I put it
here.) (This answers the question in post #1: Can I smooth the fonts on the desktop, too.)
I use it before I OCR with Finereader, forcing it to leave my pages unaltered. Version 11 allows you to save to epub directly. Although a non-linear type page with greek and schemes gets hopelessly jumbled. So I mainly save to pdf files with exact image with text underneath. Adding bookmarks in Acrobat results in a competitor for the real book! Only real problem for the digital copy is that I can't write in the margins.