On Mon, Sep 08, 2003 at 09:46:42PM +0200, Sven Neumann wrote:
> Hi,
>
> Jean-Christophe Dubacq <jean-christophe.dubacq@xxxxxxxxxxxx> writes:
>
> > As I do not think my former message reached gimp-users, I will try
> > there (it also seems more fit, and I am subscribed):
> >
> > Is there any way to directly edit the alpha layer of a layer. Layer
> > masks do only reduce the alpha, never increase it; and sometimes I
> > would like to somehow delete any opacity information in a layer,
> > without having to repaint all. So maybe there is a solution, but I
> > didn't find this (since editing a mask is not the answer)...
>
> In GIMP-1.3 this is as easy as deactivating all channels but alpha in
> the channels dialog. All paint/fill operations will only affect the
> alpha channel then.
Well... I tried my version (1.3.19). Create a red picture. Create a
new layer. Paint it black. And now, I would like to edit alpha directly
with the pen tool ('pen'ing in black should in fact let red appear,
since white is full opacity and black is transparent). But it doesn't
work: whateve color is selected, the pen does not affect alpha.
Maybe it is a bug. But the alpha layer even easily seen, is not
editable.
To answer another mail, what I want to achieve is a sort of threshold
alpha, but controlled by me (over only some part of the image, and
setting part of the alpha layer to 50% opacity)... I know of ways to
achieve that, but it makes the task troublesome.
--
JCD
