* metapost: remapping colors of an SVG picture
@ 2020-02-18 11:18 mf
2020-02-18 13:53 ` Hans Hagen
0 siblings, 1 reply; 7+ messages in thread
From: mf @ 2020-02-18 11:18 UTC (permalink / raw)
To: ntg-context
[-- Attachment #1: Type: text/plain, Size: 1939 bytes --]
Hello list,
I tried this:
\starttext
\startMPcode
picture p ; p := lmt_svg [ filename = "sample.svg" ] ;
draw p ;
color black_rgb ; black_rgb := ( 0, 0, 0 ) ;
color red_rgb ; red_rgb := ( 1, 0, 0 ) ;
remapcolor( black_rgb, red_rgb ) ;
recolor p ;
draw p shifted ( bbwidth(p) + 5mm, 0) ;
\stopMPcode
\stoptext
but recolor gives an error:
metapost log > >> picture
metapost log > ! Wrong picture color model: redpart of grey object.
metapost log > <for(picture)> _f_:=(redpart(EXPR0),
metapost log >
greenpart(EXPR0),bluepart(EXPR0));if.bou...
metapost log >
metapost log > repathed->...fi;fi;else:addto._p_.also.i;fi;endfor
metapost log >
;setbounds._p_.to._b_;_p_....
metapost log > <to be read again>
metapost log > ;
metapost log > <*> ...apcolor( black_rgb, red_rgb ) ; recolor p ;
metapost log >
draw grayed p shifted ( b...
metapost log >
My goal is to remap colors of an SVG image, like this:
\starttext
\startMPcode
picture p ; p := lmt_svg [ filename = "sample.svg" ] ;
draw p ;
color black_rgb ; black_rgb := ( 0, 0, 0 ) ;
cmykcolor black_cmyk ; black_cmyk := ( 0, 0, 0, 1 ) ;
remapcolor( black_rgb, black_cmyk ) ;
recolor p ;
draw p shifted ( bbwidth(p) + 5mm, 0) ;
\stopMPcode
\stoptext
It relates to a recent thread in the mailing list about color management.
It's an attempt to use inkscape-made SVG graphics inside a CMYK
workflow, without using color management.
Naturally it would work under some constraints, but there's a lot of
graphics you can do with Inkscape that falls inside these:
- the number of colors in the input SVG should be limited, so that every
color gets converted
- no embedded bitmaps, only vector graphics
- perhaps some other constraints on gradients, transparency, etc.
A good alternative would be a remapper based on a custom lua function
like this:
function rgb2cmyk( r, g, b )
...
return c, m, y, k
end
Massi
[-- Attachment #2: sample.svg --]
[-- Type: image/svg+xml, Size: 2796 bytes --]
[-- Attachment #3: Type: text/plain, Size: 493 bytes --]
___________________________________________________________________________________
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: metapost: remapping colors of an SVG picture
2020-02-18 11:18 metapost: remapping colors of an SVG picture mf
@ 2020-02-18 13:53 ` Hans Hagen
2020-02-18 18:07 ` Jan U. Hasecke
0 siblings, 1 reply; 7+ messages in thread
From: Hans Hagen @ 2020-02-18 13:53 UTC (permalink / raw)
To: mailing list for ConTeXt users, mf
On 2/18/2020 12:18 PM, mf wrote:
> Hello list,
> I tried this:
>
> \starttext
> \startMPcode
> picture p ; p := lmt_svg [ filename = "sample.svg" ] ;
> draw p ;
> color black_rgb ; black_rgb := ( 0, 0, 0 ) ;
> color red_rgb ; red_rgb := ( 1, 0, 0 ) ;
> remapcolor( black_rgb, red_rgb ) ;
> recolor p ;
> draw p shifted ( bbwidth(p) + 5mm, 0) ;
> \stopMPcode
> \stoptext
\setupcolors[rgb=no]
\startMPcode
draw lmt_svg [ filename = "sample.svg" ] ;
\stopMPcode
> but recolor gives an error:
> metapost log > >> picture
> metapost log > ! Wrong picture color model: redpart of grey object.
> metapost log > <for(picture)> _f_:=(redpart(EXPR0),
> metapost log > greenpart(EXPR0),bluepart(EXPR0));if.bou...
> metapost log >
> metapost log > repathed->...fi;fi;else:addto._p_.also.i;fi;endfor
> metapost log > ;setbounds._p_.to._b_;_p_....
> metapost log > <to be read again>
> metapost log > ;
> metapost log > <*> ...apcolor( black_rgb, red_rgb ) ; recolor p ;
> metapost log > draw grayed p shifted ( b...
> metapost log >
>
> My goal is to remap colors of an SVG image, like this:
>
> \starttext
> \startMPcode
> picture p ; p := lmt_svg [ filename = "sample.svg" ] ;
> draw p ;
> color black_rgb ; black_rgb := ( 0, 0, 0 ) ;
> cmykcolor black_cmyk ; black_cmyk := ( 0, 0, 0, 1 ) ;
> remapcolor( black_rgb, black_cmyk ) ;
> recolor p ;
> draw p shifted ( bbwidth(p) + 5mm, 0) ;
> \stopMPcode
> \stoptext
>
> It relates to a recent thread in the mailing list about color management.
> It's an attempt to use inkscape-made SVG graphics inside a CMYK
> workflow, without using color management.
>
> Naturally it would work under some constraints, but there's a lot of
> graphics you can do with Inkscape that falls inside these:
> - the number of colors in the input SVG should be limited, so that every
> color gets converted
> - no embedded bitmaps, only vector graphics
> - perhaps some other constraints on gradients, transparency, etc.
>
> A good alternative would be a remapper based on a custom lua function
> like this:
>
> function rgb2cmyk( r, g, b )
> ...
> return c, m, y, k
> end
>
> Massi
>
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
>
> maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage : http://www.pragma-ade.nl / http://context.aanhet.net
> archive : https://bitbucket.org/phg/context-mirror/commits/
> wiki : http://contextgarden.net
> ___________________________________________________________________________________
>
--
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://context.aanhet.net
archive : https://bitbucket.org/phg/context-mirror/commits/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: metapost: remapping colors of an SVG picture
2020-02-18 13:53 ` Hans Hagen
@ 2020-02-18 18:07 ` Jan U. Hasecke
2020-02-18 18:17 ` mf
0 siblings, 1 reply; 7+ messages in thread
From: Jan U. Hasecke @ 2020-02-18 18:07 UTC (permalink / raw)
To: ntg-context
Am 18.02.20 um 14:53 schrieb Hans Hagen:
>
> \setupcolors[rgb=no]
> \startMPcode
> draw lmt_svg [ filename = "sample.svg" ] ;
> \stopMPcode
I get this error.
! Not implemented: (unknown numeric)=(string).
<to be read again>
]
<*> ... ; p := lmt_svg [ filename = "sample.svg" ]
juh
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: metapost: remapping colors of an SVG picture
2020-02-18 18:07 ` Jan U. Hasecke
@ 2020-02-18 18:17 ` mf
2020-02-18 18:24 ` Jan U. Hasecke
0 siblings, 1 reply; 7+ messages in thread
From: mf @ 2020-02-18 18:17 UTC (permalink / raw)
To: ntg-context
Il 18/02/20 19:07, Jan U. Hasecke ha scritto:
> Am 18.02.20 um 14:53 schrieb Hans Hagen:
>
>> \setupcolors[rgb=no]
>> \startMPcode
>> draw lmt_svg [ filename = "sample.svg" ] ;
>> \stopMPcode
> I get this error.
>
> ! Not implemented: (unknown numeric)=(string).
> <to be read again>
> ]
> <*> ... ; p := lmt_svg [ filename = "sample.svg" ]
>
That's because it's LMTX only (the "lmt" prefix of "lmt_svg" should
stand for "luametatex").
You find documentation about that in LMTX docs, luametafun.pdf, chapter
"SVG".
Best wishes,
Massi
___________________________________________________________________________________
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___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: metapost: remapping colors of an SVG picture
2020-02-18 18:17 ` mf
@ 2020-02-18 18:24 ` Jan U. Hasecke
2020-02-20 9:29 ` Jan U. Hasecke
0 siblings, 1 reply; 7+ messages in thread
From: Jan U. Hasecke @ 2020-02-18 18:24 UTC (permalink / raw)
To: ntg-context
Am 18.02.20 um 19:17 schrieb mf:
> Il 18/02/20 19:07, Jan U. Hasecke ha scritto:
>> Am 18.02.20 um 14:53 schrieb Hans Hagen:
>>
>>> \setupcolors[rgb=no]
>>> \startMPcode
>>> draw lmt_svg [ filename = "sample.svg" ] ;
>>> \stopMPcode
>> I get this error.
>>
>> ! Not implemented: (unknown numeric)=(string).
>> <to be read again>
>> ]
>> <*> ... ; p := lmt_svg [ filename = "sample.svg" ]
>>
> That's because it's LMTX only (the "lmt" prefix of "lmt_svg" should
> stand for "luametatex").
Yes, with lmtx it works but there is no image in the resulting file.
juh
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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archive : https://bitbucket.org/phg/context-mirror/commits/
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___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: metapost: remapping colors of an SVG picture
2020-02-18 18:24 ` Jan U. Hasecke
@ 2020-02-20 9:29 ` Jan U. Hasecke
2020-02-20 17:30 ` Hans Hagen
0 siblings, 1 reply; 7+ messages in thread
From: Jan U. Hasecke @ 2020-02-20 9:29 UTC (permalink / raw)
To: ntg-context
Am 18.02.20 um 19:24 schrieb Jan U. Hasecke:
> Am 18.02.20 um 19:17 schrieb mf:
>> Il 18/02/20 19:07, Jan U. Hasecke ha scritto:
>>> Am 18.02.20 um 14:53 schrieb Hans Hagen:
>>>
>>>> \setupcolors[rgb=no]
>>>> \startMPcode
>>>> draw lmt_svg [ filename = "sample.svg" ] ;
>>>> \stopMPcode
>>> I get this error.
>>>
>>> ! Not implemented: (unknown numeric)=(string).
>>> <to be read again>
>>> ]
>>> <*> ... ; p := lmt_svg [ filename = "sample.svg" ]
>>>
>> That's because it's LMTX only (the "lmt" prefix of "lmt_svg" should
>> stand for "luametatex").
>
> Yes, with lmtx it works but there is no image in the resulting file.
Sorry for digging deeper.
I am very thrilled by the idea that I could simply adjust a RGB SVG to
well defined CMYK colors with this trick.
Can anybody confirm if this works?
juh
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://context.aanhet.net
archive : https://bitbucket.org/phg/context-mirror/commits/
wiki : http://contextgarden.net
___________________________________________________________________________________
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: metapost: remapping colors of an SVG picture
2020-02-20 9:29 ` Jan U. Hasecke
@ 2020-02-20 17:30 ` Hans Hagen
0 siblings, 0 replies; 7+ messages in thread
From: Hans Hagen @ 2020-02-20 17:30 UTC (permalink / raw)
To: mailing list for ConTeXt users, Jan U. Hasecke
On 2/20/2020 10:29 AM, Jan U. Hasecke wrote:
> Am 18.02.20 um 19:24 schrieb Jan U. Hasecke:
>> Am 18.02.20 um 19:17 schrieb mf:
>>> Il 18/02/20 19:07, Jan U. Hasecke ha scritto:
>>>> Am 18.02.20 um 14:53 schrieb Hans Hagen:
>>>>
>>>>> \setupcolors[rgb=no]
>>>>> \startMPcode
>>>>> draw lmt_svg [ filename = "sample.svg" ] ;
>>>>> \stopMPcode
>>>> I get this error.
>>>>
>>>> ! Not implemented: (unknown numeric)=(string).
>>>> <to be read again>
>>>> ]
>>>> <*> ... ; p := lmt_svg [ filename = "sample.svg" ]
>>>>
>>> That's because it's LMTX only (the "lmt" prefix of "lmt_svg" should
>>> stand for "luametatex").
>>
>> Yes, with lmtx it works but there is no image in the resulting file.
>
> Sorry for digging deeper.
>
> I am very thrilled by the idea that I could simply adjust a RGB SVG to
> well defined CMYK colors with this trick.
>
> Can anybody confirm if this works?
mf and i are playing with an overload mechanism (actually pretty
trivial) ... more later but in principle the answer is yes, but
- first we have to play around a bit
- then it needs to end up in the core
- then there need to be a new context upload
- and mf has to wikify it
so, some patience is needed
Hans
-----------------------------------------------------------------
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage : http://www.pragma-ade.nl / http://context.aanhet.net
archive : https://bitbucket.org/phg/context-mirror/commits/
wiki : http://contextgarden.net
___________________________________________________________________________________
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2020-02-18 11:18 metapost: remapping colors of an SVG picture mf
2020-02-18 13:53 ` Hans Hagen
2020-02-18 18:07 ` Jan U. Hasecke
2020-02-18 18:17 ` mf
2020-02-18 18:24 ` Jan U. Hasecke
2020-02-20 9:29 ` Jan U. Hasecke
2020-02-20 17:30 ` Hans Hagen
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