Spectralcalc iccGPU™ introduces new possibilities for offset color
separation.
Published for commercial use at:
https://cielab.xyz/spectralcalc_en.php
The first year of use is usually free.
iccGPU uses a graphics accelerator whenever possible
<https://www.youtube.com/watch?v=qoBvvbN2r6s> for the first time in the
history of computer color management, so the GPU is in the name.
The clear step-by-step design of profiles allows the color technologist to
control the process with the help of tables as deeply as no program can
intervene at any intermediate stage. In fact, the colorist becomes a
co-author of the programmer when creating the separation profile.
I made three color separation profiles for Fogra 39 in Spectralcalc iccGPU:
ISO Coated v2 Perceptual Skintones iccGPU
<https://cielab.xyz/forum/download/file.php?id=1200> - for maximum black
width, a fundamental exception is made in the Perceptual table to
achieve traditional
skintones with a minimum of black ink. The Relative colorimetric table does
not exclude the maximum black width for skin like it does in the Perceptual
table.
ISO Coated v2 Heavy GCR iccGPU
<https://cielab.xyz/forum/download/file.php?id=1199> - profile with maximum
black width and Heavy GCR generation for monochrome and achromatic images.
ISO Coated v2 BTAC 240 iccGPU
<https://cielab.xyz/forum/download/file.php?id=1198> is a profile with
maximum width and blended black generation with the lowest possible offset
lightness of a blend of achromatic super black (~ 60-42-38-100), but
TIL=300 in chromatic colors. For any photographic image, except for
skintones and achromatic, for them - the first and second profiles are
better suited.
Idealliance specifications are similar to ISO.
All three profiles use magenta and cyan inks UCA and yellow anti-UCA to
achieve the best possible print contrast with separations from the profiles
shown. All profiles in the Relative tables use a very special maximum black
ink width, which allows you to extract the highest possible pure saturated
color from process printing. Wherever possible, the third contaminating
color ink is replaced by black, which has less effect on the reduction of
saturation and only adjusts the lightness. Thus, all 4 colors are found in
color separation almost only in balance neutral and weakly saturated
near-neutral colors close to it.
In the creation of non-colorimetric tables Perceptual and Saturation, the
unique capabilities of the chromatic adaptation algorithm CIECAM02 are
used. The Perceptual Skintones profile makes skin a little purer when
separating with Perceptual Rendering Intent. RGB colorants are usually
lighter than CMY colorants, so the Perceptual and Saturation tables, to
preserve the saturation of the original, slightly lower the lightness of
the colorants to maintain their maximum saturation in darker CMYK process
colors. This perceptual gamut mapping is shown schematically in the
screenshot <https://cielab.xyz/thumbnails/TwoDimensionalTaylor.png>.
Black generation in gray balance
https://cielab.xyz/forum/download/file.php?id=1201&t=1
Interface
https://cielab.xyz/forum/download/file.php?id=1197&mode=view
Product support:
cielab.xyz(at)gmail.com
--
Best regards, Michael Sartakov