Re: colorizing pictures

[Hans Hagen <j.hagen@xs4all.nl>]

On 3/18/2019 7:45 PM, Henning Hraban Ramm wrote:
> \externalfigure has a "color" parameter. It used to be possible to 
> colorize greyscale pictures with that, but it doesn’t work any more:
> 
> %%%
> \setupcolors[state=start]
> \setupexternalfigures[
>      location={local,global,default},
> ]
> 
> \starttext
> 
> \externalfigure[img/minidodo_g][width=.3\textwidth,color=red] % greyscale
> \externalfigure[img/minidodo_b][width=.3\textwidth,color=green] % bitmap
> \externalfigure[cow][width=.3\textwidth,color=blue] % vector
> 
> \stoptext

from one of the manuals ...


\starttext

\definecolor [my-blue]   [c=1,m=.38,y=0,k=.64] % pms 2965 uncoated m
\definecolor [my-yellow] [c=0,m=.28,y=1,k=.06] % pms  124 uncoated m

\definespotcolor [my-blue-100]   [my-blue]   [p=1]
\definespotcolor [my-yellow-100] [my-yellow] [p=1]
\definespotcolor [my-blue-50]    [my-blue]   [p=.5]
\definespotcolor [my-yellow-50]  [my-yellow] [p=.5]

\definemultitonecolor [my-mix] [my-blue=.12,my-yellow=.28] 
[c=.1,m=.1,y=.3,k=.1]

\starttabulate[|T||]
\NC my-blue       \NC \blackrule[color=my-blue, 
width=.6\textwidth,height=5mm] \NC \NR
\NC my-blue-50    \NC \blackrule[color=my-blue-50, 
width=.6\textwidth,height=5mm] \NC \NR
\NC my-blue-100   \NC \blackrule[color=my-blue-100, 
width=.6\textwidth,height=5mm] \NC \NR
\NC my-yellow     \NC \blackrule[color=my-yellow, 
width=.6\textwidth,height=5mm] \NC \NR
\NC my-yellow-50  \NC \blackrule[color=my-yellow-50, 
width=.6\textwidth,height=5mm] \NC \NR
\NC my-yellow-100 \NC 
\blackrule[color=my-yellow-100,width=.6\textwidth,height=5mm] \NC \NR
\NC my-mix        \NC \blackrule[color=my-mix, 
width=.6\textwidth,height=5mm] \NC \NR
\stoptabulate

\useexternalfigure[demofig][mill.png][object=no,width=.2\textwidth]

\startcombination[4*1]
   {\externalfigure[demofig]}                      {no color}
   {\externalfigure[demofig][color=my-mix]}        {indexed duotone}
   {\externalfigure[demofig][color=my-blue-100]}   {spot color}
   {\externalfigure[demofig][color=my-yellow-100]} {spot color}
\stopcombination

\stoptext


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                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
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