PDF – How to Convert a PDF File to ePUB Format Without Using Calibre

Method 1

Simply use DJView and export as PDF

1. Goto Synaptic Package Manager
2. Install DJview4
3. Run DJview (Applications - Graphics - DJView4)
4. Open your .djvu document
5. : Menu - Export As: PDF

Method 2

Open the djvu file in evince
Select print ----> print to file
change .ps to .pdf and click print

Method 3

1. Goto Synaptic Package Manager

2. Install

   djvulibre-bin libdjvulibre21 okular-extra-backends evince libevdocument3 libevview3

3. Goto terminal and write

    sudo apt-get install libtiff-tools
   

4. Goto the directory where the djvu file is present. Click the right mouse button. Goto “Open In Terminal” option. Click on it. A terminal will open.

5. In that terminal write

   ddjvu -format=tiff file_name.djvu file_name.tiff
   tiff2pdf -j -o file_name.pdf file_name.tiff
   

Method 4

There is also an online converter DjVu to PDF converter

You definitely want Calibre. You can use it to convert virtually any file type to any other file type, as long as the source file doesn't have DRM (like Amazon, Adobe, etc.). If it does have DRM, check out Apprentice Alf's blog for help stripping it out with Calibre plugins. Don't use the DRM stripper to pirate books or otherwise violate your agreement with the vendor. Use it so you can enjoy your books on any device in any format.

Calibre is also an awesome e-book management program that can do virtually everything. It can manage Kindles, Android phones/tablets, etc. It can even email your books with one click to your Kindle's email address if you want. You won't be disappointed :-)

From a terminal:

sudo apt-get install calibre

Or search for it in Ubuntu Software Center

To actually convert the EPUB file you can use the following command:

ebook-convert file.epub file.pdf (For details, check this other answer)

Or you can check the details for the conversion dialog using the Calibre GUI.