Computer Graphics with Photoshop - Creating alpha-transparency mask from flat image?

Author

Creating alpha-transparency mask from flat image?

Edward J. Stembler

2003-11-24, 10:20 am

Is it possible to create an alpha-transparency mask from a flat raster
image?

For example, I have a bitmap which was alpha-blended onto a solid
color (fuschia) background. I want to be able to re-create the
original aplha-blended without the background. I think this can be
done if the program can someway consider the background color as 100%
opague and subtract from the other colors depending on their relation
to the background color. Is this possible?

Here's the flattened image I'm trying to restore to it's alpha-blended
original:

http://wwww.ejstembler.com/images/8ball.bmp

edjh

2003-11-24, 10:20 am

Edward J. Stembler wrote:

quote:

> Is it possible to create an alpha-transparency mask from a flat raster
> image?
>
> For example, I have a bitmap which was alpha-blended onto a solid
> color (fuschia) background. I want to be able to re-create the
> original aplha-blended without the background. I think this can be
> done if the program can someway consider the background color as 100%
> opague and subtract from the other colors depending on their relation
> to the background color. Is this possible?
>
> Here's the flattened image I'm trying to restore to it's alpha-blended
> original:
>
> http://wwww.ejstembler.com/images/8ball.bmp

Double-click on Background to make it a layer. Background does not
support transparency.

--
Comic book sketches and artwork:
http://www.sover.net/~hannigan/edjh.html