$ convert in.png out.pdf
ImageMagick can do much, much more than conversions. Today I learned the following trick from an
e-mail list discussion:
$ convert -trim img.pdf
which trims all the white space from around an image. It's a great trick for inserting Matlab plots into papers! I used to do this by hand with an image editing program like the GIMP; it's great to know that I don't have to fire up such a massive tool in order to accomplish this simple task. (The GIMP is a wonderful program, incidentally, but starting it up just to crop some white space is a task beneath its mighty powers.)
