Recently I bought Amazon Kindle (7th Generation). Although I read a lot of native e-books there, from time to time I need to read a PDF and sometimes the PDF is quite long and rather not e-book reader friendly.
Amazon’s “Send to Kindle by E-mail” works quite well for text only PDFs but when I have a more structured PDFs full of pictures then the service isn’t very useful and same applies for Calibre (https://calibre-ebook.com/).
When I was searching through Internet for some other Linux PDF converters I found “Willus.com’s K2pdfopt” (http://www.willus.com/k2pdfopt/) which turned out to be quite good. There are a lot of options available for PDF conversion, you can explore them in interactive mode of K2pdfopt. For me, these two commands are the best:
Just trim of empty borders
./k2pdfopt -mode tm input.pdf
Full reformat to kindle display (including re-pagination)
./k2pdfopt -w 600 -h 800 -dpi 167 -idpi -2 -m 0,1.3,0,1.3 -wrap- input.pdf