tifftopng.py

import os
from PIL import Image

yourpath = os.getcwd()
for root, dirs, files in os.walk(yourpath, topdown=False):
    for name in files:
        print(os.path.join(root, name))
        if os.path.splitext(os.path.join(root, name))[1].lower() == ".tif":
            outpath = os.path.splitext(os.path.join("dist", name))[0] + ".png"
            if os.path.isfile(outpath):
                print "exists: %s" % name
            else:
                try:
                    im = Image.open(os.path.join(root, name))
                    im_trimmed = im.crop(im.getbbox())
                    im_trimmed.thumbnail((350, 350))
                    im_trimmed.save(outpath, "PNG")
                except Exception, e:
                    print e