Recent content by mihas

It may come in handy: free utilities for working with pantones as part of proper color management. Based on CIE Lab. Based on spectra.

Yes. You can calculate profile from the original FOGRA-ECI dataset. Examples of such profiles based on standard FOGRA colorimetric data are presented here (profiles with iccGPU in the name suffix).

R.W.G. HUNT writes that the "blue turns purple problem" is embedded in the trichromatic principle itself (and not only is a cost of the CIE Lab), and its degree depends on the nature of the spectral sensitivity curves of sensors and/or spectral reflection (transmission) curves of dyes. "When a...

The spectral calculator has a significant update: now it is possible to build, in addition to CMYK, RGB profiles for printing devices with a low-cost annual subscription. In the RGB section of iccGPU profiles, the ability to turn on suppression of blue turns purple by Hung & Berns or equalize...

To match the dimensions of dE1976 and dE2000, I use factors of 0.67 kL, kC, kh. Statistic of large test charts with 1500 color fields per offset shows such a dimension ratio.

I want to show how two-dimensional gamut mapping based on CIECAM02 works in the profile perceptual table from iccGPU. For comparison, I took a perceptual table of a well-known profile from ECI - ISO Coated v2, for clarity. I tried to show it on photographs, but there is not so clear a comparison...

I would cautiously advise using relative rather than absolute colorimetry. Tint with blue pigment on the substrate to achieve neutrality will greatly reduce lightness. You may also need to use a white point compensation (WPC) algorithm for the incoming data so as not to lose detail in high...

I am afraid to work with FOGRA 51 and 52 because of the M1 filter and I am waiting for this filter to be deleted from the standard. The programs apply Lab D50 math head-on to the Lab M1 data and balance violations occur because of this, the programs simply do not know that the blue Lab M1 is not...

ISO Coated v2 MaxK MaxWidth iccGPU - profile with Max Width and skeletal black MaxK. Colored paints in the balance are mixed into black to achieve maximum contrast only below a lightness of 25; up to this threshold, a single black ink draws neutral. Thus, all four inks are not found anywhere in...

Thanks for the kind comments! Indeed, iccGPU separations are more like Argyll separations than any others. Apparently Graeme and I came to similar conclusions about the need for an inverted calculation from the inks we need to the color. And special tables Perceptual and Saturation based on...

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 for the first time in the history of computer color...

There is a A2B0, A2B1, A2B2 and B2A0... in the profiles, but not all of these tables are mirrored. Colorimetric tables are mirrored within gamut, perceptual tables are not mirrored. The inverse function is not applicable to profile tables, for the reason that B2A direction tables contain all...

That's right, density has nothing to do with color at all.

Not all developers recognize v4, and for a small color gamut of printing inks, the difference between v2 and v4 does not matter at all, v4 is not needed. Although a solution is possible and not in the version of profile.

No, the SCTV formula is not tied in any way to either the Fogra52 or Fogra39. Yes, depending on a different substrate and a different color of inks, the SCTV curves will be different. The picture shows coated paper.