Earlier quoted context omitted.
I've only had tangential contact with it, but Wikipedia claims ( https://en.wikipedia.org/wiki/DjVu#Format_licensing ) that DjVu is open, albeit they do talk about patents and I'm not qualified to say where that falls on the non-free spectrum I downloaded their example file and it's entirely binary, unlike PDF which is just pseudo-binary, but Evince did open it and it seems unlike PDF it's entirely raster based and w…
> it seems unlike PDF it's entirely raster based and would require a separate OCR layer on top of the text to make it eligible for copy-paste, if that's one of the goals Not really all that different from PDF: "Like PDF, DjVu can contain an OCR text layer, making it easy to perform copy and paste and text search operations." https://en.wikipedia.org/wiki/DjVu DjVu however really does seem to be biased toward scanned-…
That is not correct, PDF supports text spans natively; perhaps you're thinking of scanner software that merely uses PDF as a convenient packaging for their JPEGs?
I cannot defend DjVu as I've only had tangential contact with it, and for sure have never tried to author any such file. I was just raising awareness that there are competing standards that appear to be libre and are designed for pixel perfect output