our copy machines at the university can scan documents and send them to an email address. how convenient! however, when you scan pages from a book, the page-size will most likely not match the exact size of an A4 paper, resulting in a PDF document that has black borders on the side and/or the bottom. this is bad, because printing these pages later will waste a lot of ink. that’s why i’ve been looking for an easy way to crop PDF documents on linux, and i’ve finally found out how to do this:
pdfcrop –margins ‘0 0 0 -50’ –clip report.pdf
this will remove 50 bp from the bottom of every page of the PDF.
on my distro, pdfcrop is provided by the package ‘texlive-extra-utils’, so you’ll need to install this if you don’t have it already.