RGB yog additive thiab ua los ntawm lub teeb, CMYK yog subtractive thiab ua los ntawm roj inks. Kev hloov ntawm lawv yog kauj ruam txhua tus screen tsim ua ntej nws tuaj yeem luam tawm.
Yuav ua li cas RGB rau CMYK hloov ua haujlwm
- Normalise cov channel: faib R, G thiab B los ntawm 255.
- Txiav qhov channel normalised loj tshaj plaws thiab xam key K = 1 − max.
- Txiav cyan, magenta thiab yellow los ntawm kev tshem qhov black share ntawd: C = (1 − R − K) / (1 − K), thiab lwm yam.
- Hloov tag nrho plaub tus nqi mus rau percentages nruab nrab 0 thiab 100.
Qhia ua piv txwv
Nws yog kev kwv yees kev xam qauv tsis muaj color profile. Print shops siv ICC profiles thiab ink limits, yog li cov lej no yog ib qho kev piv txwv ruaj khov, tsis yog qhov tawg-rau-press.
RGB thiab CMYK piav
Dab tsi yog RGB?
RGB piav txog xim ua peb lub channel ntawm teeb — liab, ntsuab thiab xiav — txhua tus los ntawm 0 txog 255. Nws cia raws li cov zaub ua haujlwm tiag: tag nrho peb ntawm 255 yog dawb, tag nrho ntawm 0 yog dub. RGB yog qhov kev xaiv thaum twg koj xav xam nrog xim, thiab rgba() ntxiv kev pom qhov muag (transparency) ntxiv.
- Syntax:
- rgb(R, G, B)
- Range:
- 0–255 per channel
- Zoo tshaj rau:
- code, canvas, transparency with rgba()
Dab tsi yog CMYK?
CMYK yog qauv plaub-ink siv hauv kev luam: cyan, magenta, yellow thiab key (black), txhua tus ua feem pua los ntawm 0 txog 100. Ink thim teeb es tsis txhob tso tawm nws, yog li CMYK npog tsawg xim dua zaub — yog vim li cas cov xim ci ncoo ntawm zaub qee zaum zoo li tsis ci thaum luam tawm.
- Syntax:
- cmyk(C%, M%, Y%, K%)
- Range:
- 0–100% per ink
- Zoo tshaj rau:
- print, packaging, press-ready artwork
RGB rau CMYK daim ntawv reference
Cov xim CSS feem ntau, hloov los ntawm RGB rau CMYK.
| Xim | RGB | CMYK |
|---|---|---|
| black | rgb(0, 0, 0) | cmyk(0%, 0%, 0%, 100%) |
| white | rgb(255, 255, 255) | cmyk(0%, 0%, 0%, 0%) |
| red | rgb(255, 0, 0) | cmyk(0%, 100%, 100%, 0%) |
| lime | rgb(0, 255, 0) | cmyk(100%, 0%, 100%, 0%) |
| blue | rgb(0, 0, 255) | cmyk(100%, 100%, 0%, 0%) |
| yellow | rgb(255, 255, 0) | cmyk(0%, 0%, 100%, 0%) |
| orange | rgb(255, 165, 0) | cmyk(0%, 35%, 100%, 0%) |
| teal | rgb(0, 128, 128) | cmyk(100%, 0%, 0%, 50%) |
| purple | rgb(128, 0, 128) | cmyk(0%, 100%, 0%, 50%) |
| gray | rgb(128, 128, 128) | cmyk(0%, 0%, 0%, 50%) |