Zakaj je upravljanje z barvami pomembno?

Upravljanje barv je opravilo zajemanja barv na vhodni naprav, njihov prikaz na zaslonu in tisk medtem ko so natančne barve in obseg upravljane na vsakem mediju.

Potrebo po barvnem upravljanju je najbrž najlažje razložiti s fotografijo ptice na leden zimski dan.

Ptič na zmrznjenem zidu kot jo vidi fotoaparat

Običajno prikaže preveč nasičen moder kanal, ki povzroči, da je slika videti mrzlo.

To uporabnik vidi na zaslonu običajnega poslovnega prenosnika.

Notice how the white is not “paper white” and the black of the eye is now a muddy brown.

To vidi uporabnik, ko sliko natisne na običajnem brizgalnem tiskalniku.

Osnovna težava je, da vsaka naprava lahko upravlja različen obseg barv. Zato boste morda lahko zajeli fotografijo električno modre barve, vendar je večina tiskalnikov ne bo mogla natisniti.

Most image devices capture in RGB (Red, Green, Blue) and have to convert to CMYK (Cyan, Magenta, Yellow, and Black) to print. Another problem is that you can’t have white ink, and so the whiteness can only be as good as the paper color.

Another problem is units. Without specifying the scale on which a color is measured, we don’t know if 100% red is near infrared or just the deepest red ink in the printer. What is 50% red on one display is probably something like 62% on another display. It’s like telling a person that you’ve just driven 7 units of distance, without the unit you don’t know if that’s 7 kilometers or 7 meters.

In color, we refer to the units as gamut. Gamut is essentially the range of colors that can be reproduced. A device like a DSLR camera might have a very large gamut, being able to capture all the colors in a sunset, but a projector has a very small gamut and all the colors are going to look “washed out”.

In some cases we can correct the device output by altering the data we send to it, but in other cases where that’s not possible (you can’t print electric blue) we need to show the user what the result is going to look like.

For photographs it makes sense to use the full tonal range of a color device, to be able to make smooth changes in color. For other graphics, you might want to match the color exactly, which is important if you’re trying to print a custom mug with the Red Hat logo that has to be the exact Red Hat Red.