Pyhon and PIL

[Olav Viken]

Hi, I'm using Python Imaging Library (PIL) to convert a lot bmp-files from
color to monochrome images. This works, but all images are dithered
(grayscale), and what I want is to set "all colors (except white) to black".

My code looks something like this:

import Image
im = Image.open("yellow.bmp")
im = im.convert("1", dither=Image.NONE)
im.save("yellow.bmp")

Anyone?

Thanks
Olav