Xim gamut yog hais txog qib ntawm cov xim uas tuaj yeem pom los ntawm lub cuab yeej. Muaj ob hom xim gamuts, additive thiab subtractive. Additive yog hais txog cov xim uas tau tsim los ntawm kev sib xyaw xim xim los tsim cov xim kawg. Subtractive xim sib tov dyes uas tiv thaiv kev xav ntawm lub teeb uas ces ua xim.
Ntxiv vs. Subtractive
Ntxiv xim gamut yog cov qauv siv los ntawm khoos phis tawj, TV, thiab lwm yam khoom siv. Nws feem ntau hu ua RGB raws li lub teeb liab, ntsuab, thiab xiav siv los tsim cov xim.
Kev rho tawm xim gamut txoj hauv kev tswj hwm txhua qhov kev tshaj tawm xws li duab, ntawv xov xwm, thiab phau ntawv. Nws tseem yog feem ntau hu ua CMYK raws li cyan, magenta, daj, thiab dub pigments siv hauv luam ntawv.
sRGB, AdobeRGB, NTSC, and CIE 1976
txhawm rau txheeb xyuas pes tsawg xim ib lub cuab yeej tuaj yeem ua tau, nws siv ib qho ntawm cov qauv xim gamuts uas txhais tau tias muaj ntau yam xim. Feem ntau ntawm RGB-raws li xim gamuts yog sRGB. Qhov no yog cov xim gamut siv rau cov khoom siv computer, TVs, koob yees duab, video recorders, thiab lwm yam khoom siv hluav taws xob. Nws yog ib qho ntawm cov laus tshaj plaws thiab nqaim tshaj plaws ntawm cov xim gamuts siv rau lub computer thiab cov khoom siv hluav taws xob.
AdobeRGB tau tsim los ntawm Adobe ua cov xim gamut los muab ntau yam xim ntau dua li sRGB. Lub hom phiaj yog muab cov kws tshaj lij kom muaj xim ntau dua thaum lawv ua haujlwm ntawm cov duab thiab cov duab ua ntej hloov mus rau luam tawm. Qhov dav AdobeRGB gamut muab kev txhais lus zoo ntawm cov xim los luam tawm dua sRGB.
NTSC yog qhov chaw xim tsim rau ntau yam xim uas tuaj yeem sawv cev rau tib neeg lub qhov muag. Nws kuj yog tib tus neeg sawv cev ntawm cov xim pom tau tias tib neeg tuaj yeem pom thiab tsis yog qhov dav tshaj plaws xim gamut tau. Ntau tus yuav xav tias qhov no tau ua nrog cov qauv hauv TV uas nws muaj npe tom qab, tab sis nws tsis yog. Feem ntau cov khoom siv hauv ntiaj teb niaj hnub no tsis tuaj yeem ncav cuag qhov xim ntawm cov zaub.
Qhov kawg ntawm cov xim gamuts uas yuav raug xa mus rau hauv LCD saib xim muaj peev xwm yog CIE 1976. Cov xim CIE yog ib qho ntawm thawj txoj hauv kev los txhais cov xim tshwj xeeb. Xyoo 1976 ntawm qhov no yog qhov chaw xim tshwj xeeb uas qhia txog kev ua haujlwm ntawm lwm qhov chaw xim. Nws feem ntau yog nqaim thiab, vim li ntawd, yog ib qho uas ntau lub tuam txhab siv, vim nws nyiam muaj feem pua ntawm ntau dua li lwm tus.
txhawm rau txheeb xyuas ntau yam xim gamuts nyob rau hauv cov nqe lus ntawm cov txheeb ze ntawm cov xim los ntawm qhov nqaim mus rau qhov dav tshaj plaws yuav yog CIE 1976 < sRGB < AdobeRGB < NTSC. Feem ntau, cov lus qhia tau muab piv rau NTSC xim qauv tshwj tsis yog hais tias lwm yam.
Dab tsi yog xim Gamut ntawm ib qho zaub?
Cov saib feem ntau yog ntsuas los ntawm feem pua ntawm cov xim tawm ntawm cov xim gamut uas ua tau. Yog li, tus saib xyuas ntawm 100 feem pua ntawm NTSC tuaj yeem tso saib tag nrho cov xim hauv NTSC xim gamut. Ib qho screen nrog 50 feem pua ntawm NTSC xim gamut tuaj yeem sawv cev ib nrab ntawm cov xim.
Qhov nruab nrab lub khoos phis tawj saib pom nyob ib puag ncig 70 txog 75 feem pua ntawm NTSC xim gamut. Qhov peev xwm no txaus rau cov neeg feem coob, raws li 72 feem pua ntawm NTSC yog kwv yees li 100 feem pua ntawm sRGB xim gamut.
Cov CRTs siv nyob rau hauv feem ntau qub tube TVs thiab cov xim saib ua rau kwv yees li 70 feem pua ntawm cov xim gamut.
Rau cov zaub kom tau teev raws li qhov dav gamut, nws yuav tsum tsim tsawg kawg 92 feem pua ntawm NTSC xim gamut.
Ib lub LCD saib lub teeb nraub qaum yog qhov tseem ceeb hauv kev txiav txim siab nws cov xim gamut tag nrho. Cov teeb pom kev zoo tshaj plaws siv hauv LCD yog Cold-Cathode Fluorescent Teeb. Cov no feem ntau tuaj yeem tsim nyob ib ncig ntawm 75 feem pua ntawm NTSC xim gamut. Txhim kho CCFL teeb tsim muaj kwv yees li 100 feem pua ntawm NTSC. Newer LED backlighting tuaj yeem tsim ntau dua 100 feem pua. Tseem, feem ntau cov LCDs siv lub teeb ci LED uas tsis tshua muaj nqi uas ua rau qis qis ntawm cov xim gamut uas ze dua rau CCFL.
Yuav Ua Li Cas Thaum Yuav Tus Saib Xyuas
Yog lub LCD saib cov xim yog qhov tseem ceeb rau koj, nrhiav seb nws muaj pes tsawg xim nws tuaj yeem sawv cev. Chaw tsim tshuaj paus specs uas teev cov naj npawb ntawm cov xim feem ntau tsis muaj txiaj ntsig thiab feem ntau tsis raug thaum nws los txog rau qhov uas tus saib tau qhia tawm piv rau qhov nws qhov kev xav tuaj yeem pom.
Ntawm no yog daim ntawv teev npe ceev ntawm ntau qhov sib txawv rau ntau qib ntawm cov lus qhia:
- Average LCD: 70 txog 75 feem pua ntawm NTSC.
- Professional non-Wide Gamut LCD: 80 txog 90 feem pua ntawm NTSC.
- Wide Gamut CCFL LCD: 92 txog 100 feem pua ntawm NTSC.
- Wide Gamut LED LCD: Tshaj 100 feem pua ntawm NTSC.
Feem ntau cov lus qhia dhau los ntawm cov xim yooj yim calibration thaum xa khoom thiab tawm me ntsis hauv ib lossis ntau qhov chaw. Calibrate koj cov zaub nrog cov profiles thiab kev kho kom zoo siv lub cuab yeej calibration kom tau qhov zoo tshaj plaws.
