On Wed, Jul 19, 2000 at 11:18:27PM +1000, David Hodson <[EMAIL PROTECTED]> wrote:
> It's arguable that the information isn't there to start with.


> A pixel with an alpha value of 0.5 will only contribute to half the
> colour of the pixel, so it only needs half the colour information.

Since computers cannot store real numbers, there is inevitably loss of data
associated with premultiplying.

It seems to me that the disucssion should really be split into three
areas, as people are talking about different areas:

1. image loading and saving
2. internal data storage
3. composition algorithms

It seems to me that we could agree on 1. being an interface issue and 2.
being opaque to the user.

So the question is not wether gimp can handle premulitplied alpha (it
can ;) but wether the combination modes allow for the behaviour you want
(which has nothing to do with internal presentation).

I might be wrong, of course... ;)

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