"""
You can use matplotlib to generate thumbnails from existing images.
matplotlib natively supports PNG files on the input side, and other
image types transparently if your have PIL installed
"""

# build thumbnails of all images in a directory
import sys, os, glob
import matplotlib.image as image


if len(sys.argv)!=2:
    print 'Usage: python %s IMAGEDIR'%__file__
    raise SystemExit
indir = sys.argv[1]
if not os.path.isdir(indir):
    print 'Could not find input directory "%s"'%indir
    raise SystemExit

outdir = 'thumbs'
if not os.path.exists(outdir):
    os.makedirs(outdir)

for fname in glob.glob(os.path.join(indir, '*.png')):
    basedir, basename = os.path.split(fname)
    outfile = os.path.join(outdir, basename)
    fig = image.thumbnail(fname, outfile, scale=0.15)
    print 'saved thumbnail of %s to %s'%(fname, outfile)