Is there an obvious way to do this that I'm missing? I'm just trying to make thumbnails.
Define a maximum size.
Then, compute a resize ratio by taking
The proper size is
There is of course also a library method to do this: the method
Below is an (edited) example from the PIL documentation.
import os, sys import Image size = 128, 128 for infile in sys.argv[1:]: outfile = os.path.splitext(infile) + ".thumbnail" if infile != outfile: try: im = Image.open(infile) im.thumbnail(size, Image.ANTIALIAS) im.save(outfile, "JPEG") except IOError: print "cannot create thumbnail for '%s'" % infile