ImageMagick is amazing
Back in freshman year, not knowing any better, I scanned all of the handouts I received as JPEGs. My Automatic Document Feeder (ADF) got me a bit over-excited, so exploring the crustier portions of my filesystem, I find directories full of things like this:
CHEM211 - Prelim 1 - Practice Problems 01.jpg CHEM211 - Prelim 1 - Practice Problems 02.jpg CHEM211 - Prelim 1 - Practice Problems 03.jpg ...
Ad nauseam. Seeing these, I thought to myself: It be awesome if there were a utility that would take all these and bind them together in a PDF.
Meet ImageMagick's "convert" utility. It blows my mind.
convert 'CHEM211 - Prelim 1 - Practice Problems'*.jpg 'CHEM211 - Prelim 1 - Practice Problems.pdf'
Done. The resulting PDFs are pretty big, but convert can also manipulate images in just about every way imaginable — I'm just too lazy to figure out how to downsample right now.
I highly recommend checking it out. In Ubuntu's repositories you can find it using:
sudo apt-get install imagemagick