Histogram yog dab tsi? Histogram hauv kev yees duab: yuav siv li cas?

2024 Tus sau: Sierra Becker | [email protected]. Kawg hloov kho: 2024-02-26 05:10

Ntau tus kws yees duab pib pom tias nws nyuaj rau siv histogram hauv kev yees duab, thiab qee tus txawm tsis xav tias nws tsim nyog siv nws txhua. Dab tsi yog histogram, nws ua haujlwm li cas hauv kev coj ua ntawm cov kws tshaj lij, thiab dab tsi muab cov duab? Dab tsi yog txoj hauv kev zoo tshaj plaws los kho nws - los ntawm lub koob yees duab nws tus kheej lossis tom qab thaum ua cov duab los ntawm tus editor? Tus kws yees duab yuav tsum paub dab tsi txog qhov raug, qhov sib piv, chiaroscuro thiab lwm yam tseem ceeb ntawm kev yees duab? Xav paub ntxiv txog qhov no hauv kab lus.

Qhov no yog dab tsi?

Yog li, histogram - nws yog dab tsi? Ntau zaus, thaum thaij duab ib yam ntawm panorama lossis portrait, koj xa cov duab mus rau lub computer thiab xav paub yog vim li cas, nrog rau lub teeb ci ntsa iab zoo li no, lawv tig mus rau qhov tsaus ntuj dhau los lossis, qhov sib txawv, overexposed? Nws yog qhov nyuaj heev los tswj qhov ci ntawm daim duab ntawm lub koob yees duab me me "los ntawm qhov muag", tab sis koj tuaj yeem teeb tsa qhov pom kev zoo. Daim duab histogram yog ib qho cuab yeej uas qhia txog kev faib tawm lub teeb thiab tsaus tones hauv daim duab thiab tso cai rau koj kom ua tiav lawv qhov kev faib tawm.

Muaj ntau ntauhom histograms ntawm cov koob yees duab - nrog cov gradient du, nrog txhua kab, nrog cov xim thiab cov kab dub-thiab-dawb kab rov tav. Qhov nrov tshaj plaws yog nyob rau hauv daim ntawv ntawm lub tswb. Tab sis lub hauv paus ntsiab lus ntawm kev ua haujlwm yog tib yam rau txhua tus - qhov no yog daim duab qhia qhov ci ntawm daim duab los ntawm qhov tsaus ntuj tshaj plaws (sab laug) mus rau qhov pom kev (txoj cai).

Ua ntej peb xav paub yuav ua li cas nyeem cov histogram hauv ib daim duab, yuav ua li cas siv cov txiaj ntsig ntawm 0 txog 255, cia peb tau txais cov kev xav ntawm cov kws yees duab thiab txiav txim siab rau peb tus kheej seb nws puas xav tau rau lub siab- daim duab zoo, lossis koj tuaj yeem ua yam tsis muaj nws.

Myths thiab misconceptions txog histogram

Muaj ntau qhov kev sib cav txog seb puas yuav siv cov duab ci ntsa iab no. Kom nkag siab qhov no, cia peb debunk ob peb lus dab neeg hais txog yuav ua li cas thiab thaum twg siv lub koob yees duab histogram.

• Cov kws yees duab kws tshaj lij txiav txim siab chiaroscuro qhov nyiaj tshuav "los ntawm qhov muag", yam tsis muaj kev cia siab rau lub koob yees duab processor.
• Nyob ntawm qib ntawm lub koob yees duab, cov ntaub ntawv tso tawm yuav tsis raug.
• Ib daim duab tsis tas yuav tsum ntsuas kom pom qhov raug, qee zaum overexposure lossis darkening yog ib feem ntawm lub tswv yim muaj tswv yim.
• Daim duab histogram feem ntau tsuas yog siv rau kev txhaj tshuaj dub thiab dawb xwb.
• Cov kws tshaj lij feem ntau ntseeg kev ua cov duab RAW hauv Adobe Photoshop, Adobe Lightroom thiab qee qhov kho kom raug.

Nyob rau hauv qhov no, kev xav ntawm kev siv cov kab kos tau muab faib ua qhov zoo thiab qhov tsis zoo.

Kev xav tawm tsam

Cov kws tshaj lij nrog lub qhov muag tau kawmtsis tshua siv lub sijhawm no, vim tias nws siv sijhawm ntev thiab tsis tas yuav ua rau qhov xav tau. Rau ib tug pib, nws yog ib qho nyuaj heev los nyeem tam sim ntawd thiab nkag siab nyob rau hauv qhov kev taw qhia los hloov cov metering qhov tseem ceeb, ntxiv rau, ib co erroneous values thaum yees duab yuav nyuaj heev rau kho txawm nrog kev kho yav tom ntej.

Tsis yog txhua lub koob yees duab, tsuas yog cov kws tshaj lij xwb, tuaj yeem muab cov txiaj ntsig chiaroscuro tiag tiag, tab sis lawv tuaj yeem ua yuam kev. Txawm li cas los xij, yav tom ntej, daim duab yuav tsum raug kho hauv Photoshop thiab Lightroom editors, yog li ua haujlwm nrog cov histogram tsuas yog siv sijhawm zoo xwb.

Pro kev xav

Cov txiaj ntsig zoo li cas rau cov neeg paub tias histogram yog dab tsi?

• Txawm tias koj yog tus kws yees duab tshaj lij, ib pliag ob ntawm daim duab yuav qhia koj tias daim duab nplua nuj npaum li cas ntawm kev hloov pauv ntawm tonal. Ntxiv mus, hauv ntau lub koob yees duab digital koj tuaj yeem coj nws ncaj qha mus rau cov zaub thiab saib nws yam tsis tau saib los ntawm cov txheej txheem muaj tswv yim.
• Yog tias qhov kev tua tsis yog sab hauv tsev (piv txwv li, hauv qhov chaw teeb pom kev zoo), tab sis nyob rau hnub ci hauv lub tiaj ua si, nws yuav nyuaj heev rau tus kws yees duab los ntsuas cov duab ntawm lub vijtsam, vim nws tuaj yeem ci thiab qhia cov xim ntau dua faded dua li lawv muaj nyob. Thaum tsaus ntuj, ntawm qhov tsis sib xws, daim duab tuaj yeem tig mus rau qhov ci ntsa iab. Nws kuj yog ib qho nyuaj rau kev nkag siab qhov tseeb ntawm cov xim dub thiab dawb ntawm qhov screen thiab nws tsis yooj yim rau kev paub txog cov cheeb tsam twg tau "tua" los ntawm qhov sib txawv. Rau qhov no, cov cuab yeej ntsuas nruj yog qhov zoo dua - histogram hauv daim duab.
• Qee zaum nrog kev pablub histogram tuaj yeem xaiv los ntawm lub koob yees duab, nws qhia qhov dav ntawm qhov dynamic ntau yam, piv txwv li muaj pes tsawg xim lub koob yees duab tuaj yeem npog thaum tua. Tom qab tag nrho, thaum yuav lub koob yees duab, nws tsis yog ib txwm ua tau kom thaij duab uas yuav qhia tag nrho cov xim los ntawm qhov feem ntau txais ntawm 0-255.

Summarizing tag nrho cov saum toj no, to taub dab tsi ib tug histogram nyob rau hauv kev yees duab yog dab tsi, yuav ua li cas siv nws (kev siv tswv yim) tsis yog ib txwm tsim nyog, tab sis tsis superfluous, vim muaj cov xwm txheej thaum qhov kev paub no yog indispensable. Yog li cia peb kawm nyeem thiab coj mus xyaum.

Yuav ua li cas nyeem tus histogram

Yog li, dab tsi yog histogram hauv lub koob yees duab thiab vim li cas nws thiaj xav tau? Visually, nws zoo li ib daim duab. Ntawm kab rov tav axis, los ntawm sab laug mus rau sab xis, muaj qhov ntxoov ntxoo ntawm dub (tsaus) mus rau midtones (mid-brightness ntxoov) thiab dawb (lub teeb). Lub axis ntsug qhia tus naj npawb ntawm pixels ntawm txhua lub xim hauv daim duab. Yog li ntawd, peb tau txais ob peb kab ntawm qhov siab sib txawv, qhov siab dua ntawm kab, qhov ntau qhov no lossis lub teeb. Cia peb xyaum ua.

Underexposed ncej

Underexposure txhais tau tias tus ncej yuav tsaus dhau. Ntawm daim duab, lub histogram ntawm lub koob yees duab tau hloov mus rau sab laug. Yuav ua li cas rau qhov no? Qhov no txhais tau hais tias muaj ntau lub suab tsaus, cov khoom tsaus, cov xim dub, thiab yuav luag tsis muaj teeb pom kev zoo. Yog tias qhov no tsis yog lub hom phiaj ntawm daim duab, thiab koj tsis tau tua ib qho tsaus ntuj, mus rau hauv qhov chaw raug thiab ntxiv 1-2 cov ntsiab lus nce (tus nqi 1, 3; 1, 7).

Ntau tshaj tus ncej

Overexposure qhia qhov txawv, tias lub thav duab tau dhau los ua dhau los (ntau lub teeb, kev xav ntawm dej, daus hauv thav duab), lossis koj thaij duab dawb (lub teeb). Ib zaug ntxiv, yog tias qhov no tsis yog muab los ntawm cov phiaj xwm, mus rau qhov raug thiab txo nws cov nqi rau 0.7.

Qhov "yog" ncej

Tam sim no, paub tias qhov histogram zoo li cas hauv lub koob yees duab uas muaj qhov tsis raug, cia peb saib tus ncej raug raug. Visually, nws zoo li ib tug boa constrictor uas tau noj lub kaus mom. Qhov no txhais tau hais tias cov duab ntxoov ntxoo thiab lub teeb yog tam sim no thiab raug calibrated, thiab halftones yeej nyob rau hauv daim duab. Xws li ib tug ncej zoo li nthuav qhia, sib piv, meej thiab ci. Ntxiv rau nws yuav yooj yim dua.

Txoj kev phem

Qhov tsis muaj qhov tsaus ntuj thiab lub teeb, hauv lwm lo lus, sib piv, zoo li qhov no. Cov duab los yog cov tuav yog nyob rau hauv nruab nrab thiab tsis tuaj ntawm cov npoo. Qhov no tsis txhais tau hais tias tus ncej raug nthuav tawm tsis raug, tej zaum qhov no yog tus sau lub tswv yim thiab cov ntsiab lus sib txawv yuav tsum tsis txhob muaj nyob hauv daim duab. Txawm li cas los xij, qhov piv txwv no tuaj yeem kho tau yooj yim hauv kev ua tiav tom qab.

Peaks ntawm daim duab

Tus histogram muaj ob lub ncov ntse ntawm ntug. Nws yog dab tsi? Qhov kev xaiv no feem ntau tau txais thaum tua cov khoom sib txawv - hauv av nrog cov nyom tsaus thiab lub ntuj xiav, piv txwv li. Qhov kev raug mob no tsis tas yuav raug kho,vim nws yuav tsis qhia lwm yam nqi.

High key frame

Cov duab zoo li no tau txais thaum tua cov xim ci - tom qab dawb, lub ntuj ci ntsa iab hauv tshav ntuj, khaub ncaws hauv cov xim teeb. Cov histograms hauv cov duab zoo li no tau nkag mus rau sab xis, tab sis qhov no tsis yog qhov yuam kev. Daim duab hloov tawm qhov kaj, airy thiab tso cai rau koj kom mloog zoo rau lub ntsiab lus ntawm kev yees duab - ib yam khoom lossis ib tus neeg, tsis muaj kev cuam tshuam los ntawm cov ntsiab lus tsis tsim nyog.

Nyob rau hauv rooj plaub no, nws yog qhov zoo dua kom tawm ntawm qhov raug ntawm 1, vim tias cov nqi siab dua yuav ua rau muaj kev cuam tshuam ntau dhau. Qhov ci ntawm daim duab tuaj yeem nce ntxiv thaum lub sijhawm ua haujlwm.

Frame in low key

Tseem kuj muaj qhov sib txawv, thaum daim duab mus rau sab laug - piv txwv li, lub neej tseem raug yees duab tawm tsam keeb kwm dub. Ntawm no, ib yam nkaus thiab, koj yuav tsum tsis txhob ntshai ntawm qhov kev hloov pauv no, thiab kho tag nrho cov ntsiab lus, ci ntsa iab thiab qhov sib txawv uas twb muaj lawm hauv cov txheej txheem ua haujlwm. Los ntawm txoj kev, txog nws.

Editing RAW format

Tau paub tias tus histogram yog dab tsi hauv kev yees duab, siv nws li cas thaum ua daim duab? Txhua tus kws yees duab yuav tsum paub tias daim duab thaij hauv RAW hom khaws cov chaw uas nws tau coj. Yog li ntawd, nrog kev pab los ntawm Photoshop, tus tswv muaj lub sijhawm los kho qhov yuam kev.

Txawm li cas los xij, muaj qee qhov subtleties. Ib qho thav duab underexposed yog yooj yim los kho nyob rau hauv ntxiv raug, thaum lub overexposed ib tug yuav luag tsis yooj yim sua kom kho. Yog li ntawd, teeb pom kev zoozoo dua tsis mus. Txhawm rau ua qhov no, tshawb xyuas qhov raug ntawm tus ncej ntawm txhua daim duab tom qab ua haujlwm thiab siv qhov taw qhia backlight hauv lub koob yees duab teeb tsa.

Yuav ua li cas nrog cov histogram hauv Lightroom

Vim li cas siv histogram ntawm lub computer yog tias koj twb tau kho cov duab los ntawm lub koob yees duab thaum lub sijhawm tua? Nws yog qhov yooj yim, qhov no yog qhov tsim nyog txhawm rau ntsuas seb daim duab yuav zoo li cas ntawm lub khoos phis tawj nruab nrab. Tom qab tag nrho, ntawm koj phau ntawv mac nws yuav zoo tag nrho, tab sis ntawm tus phooj ywg lub laptop nws yog qhov tsaus ntuj, thiab ntawm cov ntawv luam nws txawv kiag li, tsis yog qhov koj xav tau.

Nrog Lightroom's histogram, koj tuaj yeem tau txais txhua yam ntaub ntawv koj xav tau txog duab ntxoov ntxoo, qhov sib piv, qhov ci, thiab ntau dua.

Yog li, tus histogram hauv daim duab. Yuav siv li cas thaum ua cov duab? Nyob rau hauv qhov kev pab cuam, nws zoo li ib tug zaj sawv graph. Sab xis, ib yam li hauv lub koob yees duab, yog lub luag haujlwm rau lub teeb, sab laug yog lub luag haujlwm rau cov duab ntxoov ntxoo. Qhov ntom ntawm ib qho xim tshwj xeeb yog pom nyob rau hauv ncov, qhov sib zog ntawm daim duab, qhov siab dua pixels ntawm sab xis yuav yog.

Qhov tseem ceeb tshaj plaws uas yuav tsum tau saib xyuas thaum ua tiav yog poob hauv lub teeb lossis duab ntxoov ntxoo. Yog tias tsis muaj qhov tseem ceeb ntawm ntug ntawm ib sab, ces daim duab tau poob qee cov ntsiab lus. Piv txwv li, cov plaub hau tsaus muab tso rau hauv ib qho lossis lub ntuj xiav tig mus ua dawb.

Yuav kho qhov no li cas? Hauv daim duab, koj yuav pom ob daim duab peb sab ntawm sab xis thiab sab laug. Yog tias koj nyem rau ntawm sab laug, qhov poob hauv cov duab ntxoov ntxoo yuav raug pom hauv xiav hauv daim duab. Yog tias koj nyem rau ntawm qhov yog, qhov poob yuav tig liab.

Txhawm rau kho cov kev poob no, Lightroom muaj ob pebcov cuab yeej uas nyob hauv qab daim duab yog:

• fill light;
• exposure;
• contrast;
• ntsuab;
• ntse;
• hloov xim thiab lwm yam.

Piv txwv li, qhov sib piv yuav pab kho daim ntawv qhia qhov twg tag nrho cov pixels siab nyob rau hauv ib qho kev coj, xws li daim duab muaj qhov sib txawv tsawg heev. Tus hump hauv nruab nrab hais tib yam. Tab sis qhov ntse peaks ntawm ob sab ntawm daim duab, ntawm qhov tsis sib xws, qhia qhov sib txawv ntau dhau, uas yuav tsis mob kom txo tau.

Yuav ua li cas nrog tus histogram hauv Photoshop

Cov kws yees duab tshaj lij feem ntau yuav siv Lightroom kom raug thiab kho chiaroscuro, vim tias qhov program no muaj cov cuab yeej ua tiav ntau dua thiab yooj yim dua. Txawm li cas los xij, cov duab tuaj yeem hloov kho siv Photoshop. Ntawm no tus histogram zoo li qub. Tab sis nrog kev pab los ntawm "Photoshop" nws yog qhov yooj yim los kho qhov kev daws teeb meem thiab nam piv ntawm cov duab kom ntseeg tau tias cov xim zoo dua qub thaum luam tawm cov duab. Nws kuj yog qhov yooj yim heev rau siv cov lim dej, kho qhov tsis xws luag thiab hloov cov qib ntawm cov duab.

Yog tias koj tab tom kho thiab rov kho cov duab qub, Adobe Photoshop yuav pab koj pom cov xim raug uas yuav tsum muaj nyob rau hauv qhov tseeb, qhov twg qhov tseem ceeb lossis duab ntxoov ntxoo muaj ntau.

Yuav ua li cas qhib lub histogram hauv qhov program no? Mus rau "Duab", "Kho", "Levels" tab. Koj yuav pom cov duab dub-thiab-dawb nyob rau hauv daim ntawv ntawm cov roob nrog ib thaj tsam ntawm 0 (dub ntshiab) txog 255 (dawb lub teeb). Txhawm rau hloov qhov raug, koj yuav tsum tau scroll lub stripgradient hauv qab, nrog rau cov cim hauv qab daim ntawv nws tus kheej.

Kev kawm los ntawm kev ua

Txoj cai tseem ceeb uas yuav pab koj nkag siab qhov histogram txhais li cas hauv lub koob yees duab yog xyaum ntau dua, thaij duab nrog cov ntsuas sib txawv, nyob rau hauv cov teeb pom kev sib txawv thiab niaj hnub soj ntsuam cov duab uas tshwm sim.

Ntawm ob peb daim duab zoo ib yam - ib qho ntawm +1 raug, lwm qhov ntawm +0.3, qhov thib peb ntawm -0.7. Saib seb lawv qhov sib txawv li cas. Sim hloov mus rau lwm hom kev tua. Lub sijhawm hloov pauv li cas?

Kos cov duab tib yam nrog cov duab kho kom zoo, saib seb lawv txawv ntawm lub koob yees duab li cas. Tsuas yog kev xyaum tuaj yeem ua rau koj nkag siab zoo dua thiab xav tau siv histogram.

Siv qhov xaus

Tau kawg, tsis yog tsuas yog paub tias lub histogram yog dab tsi, tab sis kev paub siv thiab kho nws kom raug yuav pab koj ua cov duab zoo thiab zoo. Tab sis kev tshaj lij yog tsim los ntawm ntau qhov kev paub me me txog kev tsis txaus ntseeg ntawm kev yees duab.

Tau kawg, txhua tus kws yees duab ntse yuav tsum paub cov cai rau kev tsim kom muaj kev vam meej, nkag siab tias yog vim li cas qee qhov kev qhia ntawv xav tau, xws li shutter speed, aperture, focus and autofocus, dynamic range, depth of field xam thiab ntau ntxiv.. Nws yuav tsum nkag siab tias qhov histogram yuav tsum zoo li cas thaum tua hauv qhov qub, qis thiab siab, thiab thaum chiaroscuro poob yog qhov qub. Qhov twg los thov overexposure rauunderlining muaj pes tsawg leeg, thiab qhov twg yog qhov tsis zoo ntawm daim duab? Tus nqi ntawm cov xim dub nyob qhov twg tiv thaiv koj los ntawm kev tsom mus rau qhov tseem ceeb ntawm daim duab?

Ib yam yog qhov tseeb, tsis paub tias tus histogram yog dab tsi, nws yuav nyuaj heev rau koj los kho cov chaw kom tau txais kev txhaj tshuaj zoo meej. Thiab seb puas yuav siv qhov kev paub no tas li lossis tsuas yog qee zaum yog koj xaiv. Hmoov zoo nrog koj cov duab tua!