I really must remember to use "Reply All" with this list. Anyhow, I answered my own question: add a "-negate" right after the -gamma 1.0 expression. Then the red is opaque and the white is transparent. http://rpresser.googlepages.com/test2.html
This is a very interesting effect. On Fri, Apr 11, 2008 at 3:53 PM, Ross Presser <[EMAIL PROTECTED]> wrote: > Following along here ... this did not do what I was expecting. > > convert \( -size 100x100 gradient:red \) \ > > \( +clone -colorspace Gray -gamma 1.0 \) \ > > +matte -compose Copy_Opacity -composite out.png > > > > The result of this is that the image is pale red and transparent at the > top, slightly darker red and less transparent in the middle, and totally > white and opaque at the bottom. I was expecting an image that was opaque and > red at the top, and completely transparent at the bottom. > > I put up a sample HTML page showing this out.png over top of a futurama > image: > http://rpresser.googlepages.com/test.html > > This may be what Christoph wanted, I dunno. But how would I do the other > thing? I'm picturing that the red channel value and alpha channel value > would be identical throughout. > _______________________________________________ Magick-users mailing list [email protected] http://studio.imagemagick.org/mailman/listinfo/magick-users
