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From: Alan BRASLAU <alan.braslau@cea.fr>
To: "Meer, Hans van der" <H.vanderMeer@uva.nl>
Cc: NTG ConTeXt <ntg-context@ntg.nl>
Subject: Re: Overlays as background in textbackground
Date: Wed, 18 May 2016 12:24:55 -0600	[thread overview]
Message-ID: <20160518122455.3fdb4772@cea.fr> (raw)
In-Reply-To: <850280A9-1EA1-474F-BA28-5A057F412C3B@uva.nl>

Here is a trick (due to Hans, of course) to produce a watermark image.
You can play with the idea in order to produce your own effect.

\definecolor [percent] [s=1,a=1,t=.9]
\externalfigure [cow] [background={foreground,color},backgroundcolor=percent]

Alan

On Wed, 18 May 2016 11:55:11 +0000
"Meer, Hans van der" <H.vanderMeer@uva.nl> wrote:

> This code from three years back ia a reply to a question of placing
> an overlay background. Because the cow is very black I am curious if
> the \externalfigure can have a paramter to change the alpha of the
> cow, making it more transparent. By the way, it is not out of
> curiosity only. If possible it would forego the need to make separate
> pictures of different transparency beforehand.
> 
> > On 15 Jul 2013, at 11:22, Hans Hagen <pragma@wxs.nl> wrote:
> > 
> > \definetextbackground [mybackgroundOverlay]
> > [mp=mpos:region:whatever]
> > 
> > \startuseMPgraphic{mpos:region:whatever}
> >    for i=1 upto nofmultipars :
> >        draw textext("\externalfigure[cow.pdf]") rotated 10 shifted
> > center multipars[i] ; endfor ;
> > \stopuseMPgraphic
> > 
> > \starttext
> > 
> >  \startmybackgroundOverlay
> >        \dorecurse{10}{\input knuth \par}
> >  \stopmybackgroundOverlay
> > 
> > \stoptext
> 
> Hans van der Meer
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      reply	other threads:[~2016-05-18 18:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-14 18:54 Marco Patzer
2013-07-14 19:36 ` Wolfgang Schuster
2013-07-14 21:58   ` Marco Patzer
2013-07-15  9:22 ` Hans Hagen
2013-07-15  9:57   ` Marco Patzer
2016-05-18 11:55   ` Meer, Hans van der
2016-05-18 18:24     ` Alan BRASLAU [this message]

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