Thanks to all, who gave suggestions. Pete sent me a line which seems to do what I want:
convert -size 100x100 gradient:red-none grad_rn.png (btw, which command does this for any direction? left-right, right-left, bottom-top?) http://accms04.physik.rwth-aachen.de/~kuku/IMgck/gb.html Since I actually need only a small strip if this to generate the drop shadow edge I tried to convert -size 17x17 gradient:#103090-none grad_bluen_17x17.png and do a background-repeat on it. But the result doesn't look so nice. Why is there an unsymmetry in the coloring resulting in that not so smooth looking effect?: (I would want to have the background repeat seamlessly) http://accms04.physik.rwth-aachen.de/~kuku/IMgck/grad-blue-none_overbackgnd.gif (that the background doesn't shine through on this one had another reason and doesn't matter here - it was contained in a <div> that had no background) I'm only concerned about the inaccuracy. Is it an Imagemagick problem (precision, rounding)? Thanks. -- Chris Christoph P. U. Kukulies On Fri, Apr 11, 2008 at 03:58:26PM -0400, Ross Presser wrote: > 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
