Re: [Inkscape-user] CMYK-safe color maps.
by gespertino＠...155...
> Imagemagick will convert a bitmap file from RGB to CMYK color space. So
> will Scribus (with the help of an icc profile of course.) So I can
> reverse the process and take the CMYK factors, key them into a color
> mapping part of Scribus or Gimp, and jot down the RGB equivalent. The
> resulting palette will be an RGB palette that is within the CMYK gamut.
>
> I just want to avoid all that labor.
You'll want to avoid more than just the labor. Depending on which
color profiles and rendering intents you use for converting RGB to
CMYK and back. the loss of precision could be huge.
Doing that you'll loose even in-gamut colors, since the conversion
isn't bidirectional and all the color values are likely to be
affected.
My suggestion is to stay away of conversions, and only use gamut
warnings to know which colors are printable and which aren't, so you
can create a color map containing untouched RGB values that are
printable in the specified target CMYK space.
Doing two conversions you'll get a map of clipped or shifted values
that have nothing to do with your original map.
And the plan is to keep only the printable colors out of an existing
color map, right?
Gez.
p.s.: Damn you, digest mode.
11 years, 8 months
Re: [Inkscape-user] Inkscape-user Digest, Vol 65, Issue 5
by gespertino＠...155...
> Imagemagick will convert a bitmap file from RGB to CMYK color space. So
> will Scribus (with the help of an icc profile of course.) So I can
> reverse the process and take the CMYK factors, key them into a color
> mapping part of Scribus or Gimp, and jot down the RGB equivalent. The
> resulting palette will be an RGB palette that is within the CMYK gamut.
>
> I just want to avoid all that labor.
You'll want to avoid more than just the labor. Depending on which
color profiles and rendering intents you use for converting RGB to
CMYK and back. the loss of precision could be huge.
Doing that you'll loose even in-gamut colors, since the conversion
isn't bidirectional and all the color values are likely to be
affected.
My suggestion is to stay away of conversions, and only use gamut
warnings to know which colors are printable and which aren't, so you
can create a color map containing untouched RGB values that are
printable in the specified target CMYK space.
Doing two conversions you'll get a map of clipped or shifted values
that have nothing to do with your original map.
And the plan is to keep only the printable colors out of an existing
color map, right?
11 years, 8 months
CMYK-safe color maps.
by john Culleton
In Inkscape one can arrive at CMYK-equivalent colors but only if one of
the four CMYK factors is zero. Is there any of the standard
Inkscape palettes that contains only colors that are convertible to
CMYK without significant color shift? I can build my own but this will
be extremely tedious.
--
John Culleton
Wexford Press
"Create Book Covers with Scribus"
http://www.booklocker.com/books/4055.html
11 years, 8 months
interpolation issue in Inkscape
by Florian Berger
Hi Inkscape community,
I have an issue with unwanted / inferior looking interpolation in
scaled Inkscape PNG exports.
In the case at hand I have a pixel art image that has been converted to
SVG using 40px x 40px vector squares for each pixel (whether or not
Inkscape is the right tool for playing with pixel art is *not* the
question here ;-) ).
When such an image is scaled down a little and exported as PNG, it
shows some poor interpolation artefacts. These artefacts are less
obvious or not present in the actual Inkscape display, but very visible
after export.
Here is an illustriation of the problem:
http://img594.imageshack.us/img594/769/inkscapeinterpolation.png
(Please view at original size first to prevent additional
interpolation.)
Please note that some of these interpolations do not seem to make
sense, e.g. using bright grey in the brown / dark red hair of the
character.
I am very aware that Inkscape may not be the weapon of choice for this
kind of operation. Still, my questions:
- Is there any way to prevent Inkscape from interpolation /
anti-aliasing upon exporting such an image?
- If this is an interpolation issue: why does Inkscape use such
inappropriate colors?
- Shall I file a bug? :)
Any hint will be appreciated.
Thanks,
Florian
11 years, 8 months
