I bought a new Kindle. When I tried to read some PDF files on Kindle, I found that the font size was too small to read. If you need to read PDF files on some small size devices like 4-inch smartphones or 6-inch e-book readers, you can optimize these PDF files for these gadgets with k2pdfopt.
k2pdfopt is a command-line utility to optimize PDF/DJVU files for mobile e-readers and smartphones. It works on multi-column files as well. Binaries for Windows, Mactonish and Linux are included in the official website. There are also GUI-frontend for this utility. We'll focus on the original command-line usage.
After downloading the k2pdfopt file, change its file mode by adding executing mode. Then, put the file into a proper directory like /usr/local/bin to use the utility.
Start the utility with the PDF/DJVU file you want to optimize, and you'll see a page of available configurations. If you are using Kindle, you may just accept the default configurations. You may also fiddle these configurations to fit your own needs. When you finish adjustments, press <Enter> to begin the conversion process.
![k2pdfopt]({{ "/images/adjust_k2pdfopt_resize.png" | prepend: site.baseurl }} 'choose k2pdfopt configurations')!
When the converting process finish, a new file with different name from original file will be produced. Copy this new file to your e-reader and enjoy your reading.