Multiple versions of PDF

[MarjaE]

I have somewhat different requirements, but I am also looking at keeping multiple copies of many pdfs.

(1) Often the original pdf in another folder outside Calibre.

(2) If the original lacks a text layer, an ocre'd version for my computer, and if the original has a text layer with incompatible rendering, a repaired version for my computer.

(3) If the original has a security lock, an unlocked version for my Kindle, and if the original has jpx images, a readable version for my Kindle. Unfortunately, these can be far larger than the original pdfs, and take too much of my limited disk space, so I'd have to create them when needed and delete them when no longer needed.

Elucidate is my current tool to ocr text-layer-less pdfs to text-layer-ful ones, but it results in very big pdfs. I can usually use other tools to re-compress these pdfs.

Willus's k2pdfopt is the simplest tool to convert incompatible pdfs to Kindle-compatible pdfs, but -odpi 300 or 150 results in very big pdfs, and -odpi 72 results in jagged lettering. I have tried using other tools to re-compress these pdfs, but what's readable on the Mac isn't necessarily readable on the Kindle. I'm thinking about creating Kindle-compatible pdfs as needed, and deleting them when no longer needed.

[MarjaE]

One possible solution is to include two book entries for the pdf.

In my case, my "To Export" virtual library includes "NOT incompatible," so if I tag the Mac versions "incompatible," then Calibre would only export Kindle-processed versions.