Chrominance: Nws yog dab tsi hauv kev tsim yeeb yaj kiab?
Chrominance yog ib qho tseem ceeb tshaj plaws ntawm video ntau lawm. Nws muaj qhov cuam tshuam loj npaum li cas cov duab pom hauv video thiab tuaj yeem siv tau txhim kho qhov zoo ntawm cov duab video.
Chrominance hais txog qhov xim, saturation, thiab siv ntawm lub xim hauv video.
Hauv tsab xov xwm no, peb yuav tham txog chrominance hauv kev nthuav dav ntxiv thiab saib nws lub luag haujlwm hauv kev tsim video.
Hauv kab ntawv no peb yuav npog:
Txhais ntawm Chrominance
Chrominance (tseem hu ua xim) yog lub hauv paus ntawm kev tsim cov yeeb yaj kiab uas nthuav tawm cov xim thiab saturation ntawm daim duab. Nws yog ib qho ntawm ob feem ntawm lub teeb liab video, lwm qhov yog nws lub teeb (kev kaj). Chrominance yog sawv cev los ntawm ob xim ua haujlwm - Cb and Cr - uas ua ke sawv cev rau cov xim palette tshwj xeeb hauv kev sib piv rau nws cov luminance tswj Y.
Chrominance muaj cov ntaub ntawv hais txog tus zoo, ntxoov ntxoo, tint thiab qhov tob ntawm cov xim hauv video signal. Piv txwv li, chrominance tuaj yeem siv los cais cov tawv nqaij tones los ntawm lwm cov xim hauv daim duab los ntawm kev txheeb xyuas cov pixels nrog qee qhov xim xim. Ib yam li ntawd, chrominance tuaj yeem siv los txhim kho cov ntsiab lus zoo li textures los yog me me variations nyob rau hauv brightness. Nyob rau hauv cov video tawm tswv yim, chrominance yog muab cais los ntawm luminance qhov tseem ceeb, tso cai rau ntau npaum compression ntawm cov ntaub ntawv yam tsis muaj kev cuam tshuam rau daim duab zoo.
Keeb kwm ntawm Chrominance
Chrominance, los yog Chroma, yog ib qho ntawm ob yam ntawm cov xim siv hauv video ntau lawm (nrog rau luminance). Nws yog xam los ntawm kev ntsuas qhov siv ntawm lub teeb ntawm tej xim - feem ntau liab, ntsuab thiab xiav. Qhov ci ntsa iab ntawm cov xim tshwj xeeb dhau los, qhov ntau chroma nws muaj.
Lub sij hawm 'chrominance' yog thawj zaug los ntawm Walter R. Gurney hauv xyoo 1937 thiab tseem tsis tau hloov pauv txij li thaum ntawd. Txij thaum ntawd los, nws tau siv dav hauv kev tsim khoom hauv TV raws li nws cov xim tseem ceeb (liab, ntsuab thiab xiav) zoo sib xws rau cov xim hauv TV txij thaum pib. Thaum lub TV niaj hnub no tsis yog cov kab hluav taws xob cathode raws li cov ntaub ntawv chroma thiab luma, ntau lub koob yees duab niaj hnub tseem siv cov khoom no los sau cov duab xim.
Chrominance tso cai rau kev sau cov xim ntau dua li qhov muaj los ntawm monochrome (dub thiab dawb) zaj duab xis ua ntej kev txhim kho cov tshuab ua yeeb yaj kiab hauv xyoo 1931. Chrominance feem ntau yog ntsuas siv oscilloscope lossis waveform monitor uas txheeb xyuas qhov hloov maj mam hloov xim hauv txhua qhov chaw. ntawm daim duab yees duab - txawm tias qhov tsis pom ntawm qhov muag liab qab - kom ntseeg tau tias cov xim nyob ib puag ncig ntawm lub koob yees duab thiab cov khoom siv thaum lub sijhawm ua haujlwm tom qab tsim tawm xws li kho thiab hloov pauv rau cov ntawv faib tawm digital xws li cov kev pabcuam hauv internet streaming lossis disc media xws li Blu-duab tshav discs los yog DVDs.
Cheebtsam ntawm Chrominance
Chrominance yog cov ntaub ntawv xim hauv ib daim duab lossis yees duab uas pab tsim kom muaj kev nkag siab ntawm naturalness. Chrominance muaj ob yam: Hawj txawm thiab kev tsuas xyaus.
- Hawj txawm yog qhov tseeb xim ntawm daim duab.
- Kev tsuas xyaus yog tus nqi ntawm cov xim ntshiab tam sim no hauv daim duab.
Ob qho tib si yog qhov tseem ceeb ntawm kev tsim cov yeeb yaj kiab thiab yuav tau tham ntxiv hauv qab no.
Pib nrog koj tus kheej nres cov lus tsa suab storyboards
Sau npe yuav mus rau peb tsab ntawv xov xwm thiab tau txais koj dawb download nrog peb storyboards. Pib nrog coj koj cov dab neeg ciaj sia!
Peb tsuas yog siv koj li email chaw nyob rau peb tsab ntawv xov xwm thiab hwm koj tus kheej
Hawj txawm
Hawj txawm yog ib qho ntawm cov khoom uas ua rau chrominance. Nws yog lub sij hawm siv nyob rau hauv video ntau lawm los sawv cev ib tug xim txoj hauj lwm raws ib spectrum los ntawm liab rau ntsuab rau xiav. Lub xim yog txiav txim siab seb cov xim twg yog tam sim no thiab yuav ua li cas saturated nws tshwm nyob rau hauv ib daim duab. Hue tuaj yeem sawv cev ua tus lej ntawm 0i360 tig, nrog 0 yog liab, 120 yog ntsuab, thiab 240 yog xiav. Txhua qib tau muab faib ua qhov nce ntxiv ntawm 10, nrog rau cov txiaj ntsig hexadecimal xws li 3f36f ua sawv cev tshwj xeeb hues.
Ntxiv nrog rau cov lus txhais peb-channel monochrome hue ib txwm muaj, qee qhov kev siv cov duab siv plaub- lossis tsib-channel hue txhais rau cov lus piav qhia ntau dua ntawm cov xim sib txawv.
Kev tsuas xyaus
Kev tsuas xyaus, qee zaum hu ua chroma or chrominance, yog ib feem ntawm cov xim hauv kev tsim video. Saturation ntsuas tus nqi ntawm grey hauv ib xim. Piv txwv li, ib lub txiv qaub ntsuab muaj ntau saturation dua li greyish-ntsuab yuav; tib lub ntsuab tuaj yeem muaj qhov sib txawv ntawm qhov sib txawv nyob ntawm seb nws ci li cas. Thaum saturation yog nce rau ib daim duab, nws cov xim thiab brilliance ua ntau khaus; Thaum nws txo qis, xim thiab brilliance diminish.
Qhov ntsuas uas piav qhia txog qib ntawm saturation hauv ib daim duab yog hu ua qib chrominance; qhov no yog hais txog tones los ntawm dub (tsis muaj chrominance) mus txog rau tag nrho saturated hues ntawm lawv qhov siab tshaj plaws siv. Los ntawm kev kho cov qib no koj tuaj yeem ua cov xim kho lossis tsuas txhim kho cov xim hauv koj cov duab los ntawm kev ua kom cov suab nrov los yog tsim qhov sib txawv ntawm qhov tsaus ntuj thiab lub teeb xim. Qhov no tuaj yeem siv thoob plaws txhua qhov xim hauv koj daim duab, lossis tawg thiab kho los ntawm cov xim tshwj xeeb uas suav nrog txhua qhov chaw cuam tshuam ntawm tus ncej (xws li liab los yog xiav).
luminance
Luminance yog ib qho tseem ceeb ntawm chrominance thiab cuam tshuam nrog kev nkag siab ntawm qhov ci. Nyob rau hauv txhua qhov chaw muab xim, luminance yog qhov kev ntsuas ntawm yuav ua li cas ci los yog npub ib yam xim zoo nkaus li. Qib ntawm luminance tuaj yeem cuam tshuam li cas cov ntsiab lus tshwm nyob rau hauv cov ntsiab lus ntawm qhov sib txawv, saturation, thiab xim qib.
Hauv kev tsim video, luminance plays lub luag haujlwm tseem ceeb hauv kev txiav txim siab brightness ntawm ib daim duab. Piv txwv li, yog tias ib daim duab muaj cov luminance siab dhau lawm, nws yuav tshwm sim ntxuav tawm thiab npub, thaum ib daim duab uas tsis tshua muaj luminance yuav tshwm tsaus nti thiab av nkos. Yog li ntawd, cov neeg tsim yeeb yaj kiab yuav tsum kho cov qib luminance kom ua tiav qhov xav tau rau txhua qhov chaw.
Feem ntau cov haujlwm ua yeeb yaj kiab suav nrog a "luma nkhaus" uas tso cai rau cov kws tshaj lij video ua qhov hloov maj mam hloov kho cov duab zoo rau cov khoom siv tso tawm xws li TV cov ntxaij vab tshaus lossis cov projectors digital uas muaj cov yam ntxwv sib txawv rau kev txhais cov ntaub ntawv xim. Luma nkhaus yog suav nrog kaum rau cov ntsiab lus uas sawv cev rau 16 cov kauj ruam muab faib sib npaug ntawm lub teeb-tsaus teev (los ntawm 0-3) nyob rau hauv ib qho tshwj xeeb uas sawv cev rau xoom dub ntawm sab laug thiab dawb ntawm sab xis qhia qhov tseeb tag nrho tonality hla cov duab nyob rau hauv tag nrho cov kab ke lossis kev pab cuam. .
Hom Chrominance
Chrominance yog ib lo lus siv hauv kev tsim video los piav txog qhov sib txawv ntawm luminance thiab chromaticity. Nws yog siv los ntsuas qhov saturation ntawm cov xim nyob rau hauv ib tug yees duab, thiab kuj yuav siv tau los xyuas cov kev hloov nyob rau hauv brightness thiab xim.
Muaj ob hom Chrominance: lub teeb thiab chrominance. Txhua hom muaj nws tus yam ntxwv tshwj xeeb thiab cov txiaj ntsig rau kev tsim cov yeeb yaj kiab. Peb yuav tshawb txog ob hom hauv kab lus no.
RGB
RGB (liab, ntsuab, xiav) yog xim qauv siv feem ntau hauv digital video tsim thiab tsim thaum sib txuas cov xim thawj rau cov duab lossis yees duab. RGB tsim lub teeb dawb los ntawm peb lub teeb ci xim uas sib xyaw ua ke los tsim ib lub teeb ci. Qhov txheej txheem xim no tsim cov xim zoo li lub neej los ntawm kev nthuav tawm cov xim ntau tshaj plaws ua ke kom ua raws li qhov ua tau zoo li qhov tuaj yeem pom los ntawm tib neeg lub qhov muag.
Lub hauv paus yog teeb tsa siv peb-channel encoder rau qhov sib npaug ntawm qhov saturation thiab ci ntsa iab, tso cai rau txhua xim xim (liab, xiav thiab ntsuab) kom tswj tau nws tus kheej ntawm lwm tus. Lub ntsiab kom zoo dua ntawm cov qauv no yog nws cov kev ua tau zoo heev nyob rau hauv cov nqe lus ntawm brightness thiab raug thaum nws los tsim cov xim vibrant.
YUV
YUV, tseem hu ua YCbCr, yog lub luminance (Y) thiab ob chrominance Cheebtsam (U thiab V). Cov chrominance Cheebtsam ntawm qhov chaw xim digital qhia tias muaj yeeb yuj lub teeb liab li cas. YUV, feem ntau siv hauv digital photography thiab videotaping, yog kev sib txuas ntawm luminance thiab ob chrominance qhov tseem ceeb uas sawv cev rau qhov sib txawv ntawm cov cim liab thiab xiav. Lub kaw lus no tso cai rau txo qis bandwidth uas yuav tsum tau muab piv rau kev ua haujlwm RGB cov teeb liab hauv kev tsim cov yeeb yaj kiab.
Hauv YUV qauv, liab teeb liab yog sawv cev raws li "LOSSIS" thaum xiav teeb liab yog sawv cev li "V", nrog rau lub luminance (Y). U thiab V teeb liab raug rho tawm los ntawm tag nrho cov teeb pom kev zoo los sawv cev cov ntsiab lus muaj yeeb yuj hauv daim duab. Kev sib koom ua ke peb qhov tseem ceeb no ua rau peb muaj kev cuam tshuam rau qhov yuav tsum tau muaj bandwidth thaum ua kom zoo zoo thaum lub sij hawm video encoding / streaming txheej txheem.
YUV xim hom yog ib txwm txhawb nqa los ntawm cov neeg siv khoom siv ntau lub koob yees duab video zoo li JPG cov duab cov ntaub ntawv coj los ntawm cov xov tooj ntawm tes uas feem ntau ntes cov duab siv YUV hom ua ntej compressing rau hauv JPEGs. Ntxiv rau ntawm kab, thaum streaming lossis encoding cov duab no nws pab tau ntau heev vim cov ntaub ntawv tsawg dua yuav tsum tau xa mus vim nws zoo dua. zoo-rau-bandwidth ration zog. Vim hais tias ntawm cov yam ntxwv no nws nyiam tshaj RGB rau kev tshaj tawm cov hom phiaj uas qhov kev poob qis tuaj yeem xav tau vim nws tsawg bandwidth yuav tsum tau thaum raug saws rau encoding/streaming txheej txheem.
YOG
YOG yog hom chrominance feem ntau siv nrog cov laus NTSC analog video tawm tswv yim. Cov Y tivthaiv ntes cov luminance ntawm daim duab, thaum cov khoom kuv thiab Q ntes cov xim lossis chrominance. Nws ua haujlwm los ntawm kev sib cais ib qho xim rau hauv nws qhov chaw raws li xy axis, txwv tsis pub nws hu ua Hue (H) thiab Saturation (S). Cov txiaj ntsig YIQ yog siv los ua ib qho RGB matrix uas tso cai rau kev tsim cov xim raug ntau dua ntawm cov tshuab sib txawv.
YOG Qhov tseem ceeb siv lub teeb liab RGB thiab faib nws ua peb yam:
- Y (Luminance)
- I (hauv-theem xim)
- Q (quadrature xim)
Qhov sib txawv ntawm theem thiab plaub qhov sib txawv yog qhov hloov maj mam, tab sis qhov tseem ceeb kuv ntes ib khub ntawm cov xim thawj, thaum Q ntes ob khub. Ua ke peb cov channel no muaj peev xwm tsim kom muaj kev hloov pauv tsis tu ncua hauv cov xim, saturation, thiab ci ntsa iab uas ua rau cov neeg saib tuaj yeem tsim lawv tus kheej cov kev paub saib.
YCbCr
YCbCr (feem ntau hu ua Y'CbCr) yog hom chrominance uas yog tsim los ntawm peb cov channel. Cov channel no yog loj (Y), xiav-difference chroma (Cb) thiab liab sib txawv chroma (Cr). YCbCr yog raws li qhov analog version hu ua YPbPr, ua rau nws zoo sib xws hauv qee txoj hauv kev rau RGB xim qhov chaw. Txawm hais tias YCbCr feem ntau yog siv hauv kev tsim cov yeeb yaj kiab, cov duab digital yuav raug encoded nrog tib hom.
Lub tswv yim tom qab YCbCr yog tias nws txo cov ntaub ntawv xav tau los sawv cev cov duab xim. Los ntawm kev sib cais tawm cov ntaub ntawv tsis-luminance rau hauv ob txoj hauv kev, tag nrho cov ntaub ntawv rau tag nrho cov duab tuaj yeem txo qis heev. Qhov no tso cai rau zoo dua video lossis cov duab digital nrog cov ntaub ntawv me me, ua rau lawv yooj yim rau khaws thiab xa tawm.
Txhawm rau kom ua tiav qhov kev txo qis hauv cov ntaub ntawv loj, ntau theem ntawm qhov tseeb yog siv ntawm txhua qhov channel. Lub luma yuav muaj kev daws teeb meem ntawm 8 ntsis thiab chrominance 4 lossis 5 ntsis. Nyob ntawm seb hom khoom siv twg koj siv muaj ntau theem, suav nrog:
- 4:4:4 thiab 4:2:2 (4 ntsis rau txhua tus channel),
- 4:2:0 (4 khoom rau luma, 2 rau xiav thiab 2 rau liab).
Kev siv ntawm Chrominance
Chrominance, thaum siv hauv video ntau lawm, hais txog kev siv xim hauv video. Chrominance yog ib qho cuab yeej tseem ceeb rau kev tsim kom muaj kev nthuav dav thiab pom tseeb, tso cai rau cov thawj coj los txhim kho cov kev xav thiab kev xav ntawm qhov chaw.
Kab lus no yuav tshawb txog ntau txoj hauv kev uas chrominance tuaj yeem siv rau hauv kev tsim video, suav nrog kev siv:
- Xim grading
- Xim keying
- Xim palettes
Xim Grading
Ib qho ntawm cov kev siv tseem ceeb tshaj plaws ntawm chrominance hauv kev tsim video yog xim kev qhuab qhia. Xim grading yog ib txoj hauv kev los txhim kho cov duab video. Raws li lub npe implies, nws siv ntau yam txuj ci los kho xim, saturation thiab lwm yam zoo los ua kom txhaj tshuaj sawv ntsug lossis sib xyaw rau hauv nws ib puag ncig. Chrominance qib tshwj xeeb tshaj yog rau cov txheej txheem no, raws li lawv tuaj yeem siv los tsim ib qho kev xav lossis lub suab.
Piv txwv li, yog tias qhov xwm txheej tau teeb tsa los ntawm ntug dej hiav txwv thaum kaj ntug thiab nws yuav tsum muaj qhov kev xav zoo, cov qib chrominance tuaj yeem hloov kho raws li kev txhim kho lub hnub sov sov thiab ntxiv cov xim xiav xiav rau qhov pom kev zoo nkauj. Ib yam li ntawd, yog tias ib qho chaw xav tau kev xav ntau dua lossis ua yeeb yam, cov qib saturation tuaj yeem nce ntxiv thaum tseem tswj hwm qhov kev ncaj ncees ntawm cov duab qub zoo los ntawm kev kho los ntawm kev tswj hwm chrominance.
Kev muab qhab nia xim pab kom ntseeg tau tias txhua qhov kev txhaj tshuaj nyob rau hauv ib qhov project tshwm sim zoo ib yam ntawm cov suab nrov thiab hnov zoo li kev kho thiab tom qab kev tsim khoom mus smoother.
Video Compression
Video compression yog txheej txheem ntawm tshem tawm cov ntaub ntawv los ntawm lub teeb liab video thiaj li yuav txo tau cov ntaub ntawv loj los yog kis tau tus mob bandwidth. Qhov no suav nrog txo qhov nthuav dav thiab / lossis kev daws teeb meem ntawm ib qho video muab. Chrominance yog qhov tseem ceeb tshwj xeeb rau cov txheej txheem no vim nws txiav txim siab cov ntsiab lus xim hauv lub teeb liab video.
Los ntawm kev txo cov chrominance, video compression tuaj yeem ua rau muaj txiaj ntsig zoo ntawm kev txuag cov ntaub ntawv thiab kev sib kis tau yooj yim, nrog me ntsis cuam tshuam rau qhov zoo. Chrominance tuaj yeem siv rau ntau hom kev tshaj tawm, xws li kev tshaj tawm hauv TV, streaming yeeb yaj duab thiab Blu-duab tshav discs.
Raws li chrominance nqa cov ntaub ntawv tseem ceeb uas peb hu rau xim, encoding nws sparingly tab sis zoo tso cai rau peb kom compress cov yeeb yaj duab yam tsis tau txi cov xim raug lossis saturation - ob qho tseem ceeb hauv kev tsim. kev pom tseeb. Chrominance cuam tshuam ntau npaum li cas cov ntaub ntawv yuav tsum khaws thiab / lossis xa cov ntsiab lus audio-visual; los ntawm kev siv nws tag nrho, peb qhia tau tias nyob twj ywm tsawg heev thaum tswj a qib siab zoo hauv peb qhov kev pom.
xim Kho
Ib chrominance teeb liab yog ib qho uas piav txog cov xim ntawm cov duab, tsis yog qhov ci. Hauv kev tsim cov yeeb yaj kiab thiab kev ua tiav tom qab, kev txiav txim siab zoo chrominance sib npaug suav nrog kev siv software los kho cov xim kub ntawm ib daim duab lossis footage. Qhov no yog txheej txheem hu ua xim kho.
Kev kho xim hauv video tom qab tsim khoom feem ntau xa mus rau kev hloov pauv ntawm cov duab uas twb muaj lawm xws li nce lossis txo qis saturation, kho qhov nyiaj tshuav dawb, thiab hloov qee yam ntawm qhov sib txawv. Cov kev kho no tuaj yeem hloov kho cov duab zoo nkauj los ntawm kev hloov kho qhov teeb thiab qhov tsaus ntuj li cas, cov xim sib xyaw ua ke, siv cov xim sib txawv ntawm qhov pom, thiab ntau dua.
Nyob rau hauv luv luv, kev hloov kho rau chrominance yog ib qho cuab yeej rau muab txhua qhov chaw rau lub suab thiab lub siab xav uas tau txiav txim siab ua ntej. Kev kho xim feem ntau tshwm sim thaum muaj cov xim tsis raug lossis tsis sib xws ntawm cov duab uas tuaj yeem ua rau tsis meej pem thaum sim txhais nws lub ntsiab lus lossis lub hom phiaj. Piv txwv li, yog tias teeb pom kev ntawm teeb tsis zoo ib yam los ntawm scene-rau-scene ces qhov no tuaj yeem ua rau muaj qhov sib txawv ntawm cov xim ntawm ob qhov kev txhaj tshuaj coj feeb sib nrug ntawm ib leeg. Nrog chrominance hloov kho qhov tsis meej pem no tuaj yeem daws tau los ntawm kev coj txhua yam rov qab rau hauv kev sib haum xeeb nrog nws tus kheej - tshwj xeeb txog nws cov xim - yog li nws zoo nkaus li teeb pom kev zoo thiab ua kom zoo raws li qhov uas tau pom los ua ib feem ntawm lub hom phiaj zoo nkauj.
xaus
Los xaus, chrominance yog ib qho ntawm cov xim uas tuaj yeem hloov pauv thiab hloov pauv thaum tsim cov yeeb yaj kiab. Chrominance, los yog chroma luv luv, yog txiav txim los ntawm kev ntsuas lub xim thiab saturation ntawm ib qho xim los muab nws qhov txawv txav. Manipulating chrominance yog cov cuab yeej muaj zog rau cov neeg ua yeeb yaj kiab, vim lawv tuaj yeem siv los tsim surreal thiab zoo nkauj scenes nrog cov txuj ci teeb pom kev zoo.
Los ntawm kev nkag siab txog cov hauv paus ntsiab lus ntawm chrominance, cov neeg ua yeeb yaj kiab tuaj yeem muaj kev tswj xyuas ntau dua ntawm cov cua ntawm lawv cov haujlwm.
Nyob zoo, Kuv yog Kim, niam thiab ib tus neeg nyiam nres nrog keeb kwm yav dhau los hauv kev tshaj tawm thiab kev txhim kho lub vev xaib. Kuv muaj kev mob siab rau kev kos duab thiab kev ua yeeb yam, thiab tam sim no kuv tab tom dhia taub hau ua ntej mus rau hauv lub ntiaj teb nres. Nrog rau kuv qhov blog, Kuv tabtom qhia kuv cov kev kawm nrog koj.
