Chroma Subsampling 4:4:4, 4:2:2 thiab 4:2:0
Tej zaum koj tau pom 4: 4: 4, 4: 2: 2 thiab 4: 2: 0 tus lej thiab lwm yam hloov pauv, ntau dua yog qhov zoo dua?
Txhawm rau nkag siab qhov tseem ceeb ntawm cov npe no, koj yuav tsum paub tias cov lej no txhais li cas thiab lawv cuam tshuam li cas video. Hauv tsab xov xwm no peb txwv peb tus kheej rau 4: 4: 4, 4: 2: 2 thiab 4: 2: 0 chroma subsampling algorithms.
Hauv kab ntawv no peb yuav npog:
Luma thiab Chroma
Cov duab digital yog tsim los ntawm pixels. Txhua pixel muaj qhov ci thiab xim. Luma stands rau clarity thiab Chroma stands rau xim. Txhua pixel muaj nws tus nqi Luminance.
Subsampling yog siv nyob rau hauv Chrominance siv tus nqi ntawm cov ntaub ntawv nyob rau hauv ib tug duab sparingly.
Koj siv Chroma ntawm ib pixel los xam tus nqi ntawm cov pixels nyob sib ze. Ib daim phiaj feem ntau siv rau qhov no uas pib ntawm 4 cov ntsiab lus siv.
Piv txwv ntawm Chroma subsampling
Lub chroma subsampling yog qhia nyob rau hauv cov piv txwv nram qab no: J: a:b.
J = tag nrho cov pixels hauv qhov dav ntawm peb cov qauv siv thaiv
a = tus naj npawb ntawm cov qauv chroma hauv thawj (sab saum toj) kab
b = tus naj npawb ntawm cov qauv chroma hauv kab thib ob (hauv qab).
Saib daim duab hauv qab no rau qhov 4: 4: 4 chroma subsampling
4:4:4
Hauv cov matrix no, txhua pixel muaj nws cov ntaub ntawv Chroma. Cov codec Tsis tas yuav kwv yees qhov Chroma tus nqi yuav tsum yog vim nws tau sau tseg hauv txhua pixel.
Qhov no muab cov duab zoo tshaj plaws, tab sis tshwj tseg rau cov koob yees duab hauv ntu siab tshaj plaws.
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
4:2:2
Thawj kab tsuas tau txais ib nrab ntawm cov ntaub ntawv no thiab yuav tsum suav cov seem. Cov kab thib ob kuj tau txais ib nrab thiab yuav tsum suav cov seem.
Vim tias cov codecs tuaj yeem ua qhov kwv yees zoo heev, koj yuav pom yuav luag tsis muaj qhov sib txawv nrog 4: 4: 4 duab. Ib qho piv txwv nrov yog ProRes 422.
4:2:0
Thawj kab ntawm pixels tseem tau txais ib nrab ntawm Chroma cov ntaub ntawv, uas yog txaus. Tab sis kab thib ob tsis muaj cov ntaub ntawv ntawm nws tus kheej, txhua yam yuav tsum tau suav nrog nyob ib puag ncig pixels thiab cov ntaub ntawv luminance.
Tsuav muaj qhov sib txawv me me thiab cov kab ntse hauv cov duab, qhov no tsis yog teeb meem, tab sis yog tias koj yuav hloov kho cov duab hauv kev tsim khoom tom qab, koj tuaj yeem khiav mus rau qhov teeb meem.
Yog tias cov ntaub ntawv Chroma tau ploj ntawm daim duab, koj yuav tsis tau rov qab. Hauv kev muab qhab nia xim, pixels yuav tsum "kwv yees" ntau npaum li pixels tsim nrog Chroma qhov tseem ceeb, lossis thaiv cov qauv nrog cov xim zoo sib xws uas tsis sib haum rau qhov tseeb.
Nrog a Chroma yuam sij Nws dhau los ua nyuaj heev kom cov npoo nruj, cia ib leeg haus luam yeeb thiab cov plaub hau, cov ntaub ntawv ploj lawm kom paub cov xim kom raug.
A 4: 4: 4 daim phiaj tsis yog ib qho tseem ceeb, tab sis yog tias koj xav kho cov duab tom qab, nws yuav pab kom muaj cov ntaub ntawv Chroma ntau npaum li sai tau.
Ua hauj lwm nrog qhov zoo tshaj plaws subsampling qhov tseem ceeb kom ntev li ntev tau, thiab tsuas yog hloov mus rau tus nqi qis dua ua ntej tshaj tawm, piv txwv li hauv online.
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.
