PIL & TIFF transparency?

[Robin Becker]

In article <a4638b9b.0307301650.65e6f08b at posting.google.com>, Myles
<myles at geocities.com> writes
>Robin Becker <robin at jessikat.fsnet.co.uk> wrote in message news:<bPFXEJAEJ7J$Ewf
>Y at jessikat.fsnet.co.uk>...
>> Has anyone done transparency with PIL & TIFF? I'm using PIL to generate
>> a preview TIFF for embedding into an eps file and am being asked for the
>> TIFF to support transparency.
>
>Simple example that makes pure white areas of an RGB image transparent
>(there's probably a better way to create the mask, and a better way to 
>add the mask to the image, but this gives you a starting point):
>
>import Image, ImageChops
>im = Image.open('/junk/pickme.png')
># create mask (will become alpha band i.e. transparency)
>mask = im.point(lambda i : i == 255 and 255)   # create RGB mask
>mask = mask.convert('L')                       # mask to grayscale
>mask = mask.point(lambda i : i == 255 and 255) # mask to B&W grayscale
>mask = ImageChops.invert(mask)
># merge mask with image
>R, G, B = im.split()
>nuimg = Image.merge('RGBA', (R, G, B, mask))
>nuimg.save('/junk/out.tif', 'tiff')
>
>Regards, Myles.
thanks very much, I didn't know the TIFF format even supported
transparency till yesterday and now you say the PIL tiff plugin will
handle it ok. Great work pythoneers!
-- 
Robin Becker