How do you create full-screen images from each of the slides of a Google Docs presentation without too much manual work? For the previous blog post on my Munin keynote, I wanted to include some pictures from my 90-slide presentation. There is probably a point and click solution to this problem, but it is even more fun to use some command line tools to help out. These commands have been tested on Ubuntu 19.10, but should probably work on many other systems as well, as long as you have installed pdfseparate and convert.
After exporting a PDF from the Google Presentation, I made a separate PDF file of each slide using this command:
pdfseparate input.pdf output%d.pdf
This creates a bunch of PDF files with a running number. Then I ran this little for loop:
for i in *.pdf; do name=`echo $i | cut -d'.' -f1`; convert -density 200 "$i" "$name.png"; done
And voila, then I had nice PNG files of all my slides. I found that the trick is to use the “-density 200” setting (choose the density that suit your needs), since the default resolution and quality is too low.