There are several ways I've handled PDF -> <MOBI/LRF/ePUB>
Convert to a Reflowable format (30min-2hr)
The best tool to convert PDF to MOBI is called
MobiCreator, it's a free software own by MobiPocket. This software converts PDF to MOBI. You can also use MobiReader that automatically converts PDF->MOBI by adding the PDF to the MOBI library. MobiCreator does a better job but is slightly harder to use.
Calibre can convert a PDF to MOBI, it has gotten better but I still like mobicreator better.
TRIM the PDF (time spent 1min)
You can try soPDF this tool trims the PDF margins, since most PDF have a 2" margin this reduces the PDF and preservers the format of the PDF. This method works great if the PDF is a book since most PDF books are about 6"x9". If the PDF are made for Paper 8.5x11" this tool does not work well.
Convert to Image (10min)
This is the least desireble feature, it converts the PDF to an image then optimizes the image for the screen size.
This way the text is reserved but the size is exploded.
PaperCrop is the best of these tools and even reflows the text.
My approach is to first use soPDF, PaperCrop, then MobiCreator.
They all have their pro/cons but my approach is to use the solution that is quickest with acceptable reading results. MobiCreator always yeilds the best results but it is time consuming for the types of PDFs I read, for plain text based PDF MobiCreator might be the best solution for you.
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