Hi all, I got quite a lot further now. Here's the script I have so far: import PIL.Image import os.path import cStringIO def MakeThumb(self, image, width, height): oriImage = getattr(self, image) oriFile = cStringIO.StringIO(oriImage.data) image = PIL.Image.open(oriFile) image.thumbnail((width, height)) thumbnailImage = StringIO() image.save(thumbnailImage, "JPEG") thumbnailImage.seek(0) return thumbnailImage.getvalue() this all works find if you use it as: <dtml-var "PHTO_MakeThumb('AB_action_inbox.jpg', 160, 120)"> As soon as you want to do something like: <dtml-var "PHTO_MakeThumb('/images/AB_action_inbox.jpg', 160, 120)"> you get an AttributeError. Does anybody has a way around this? Cheers, Pieter