Chrominance: Kodi Mukupanga Makanema Ndi Chiyani?

pa kim Zasinthidwa: June 27, 2022

Chrominance ndi chimodzi mwa zinthu zofunika kwambiri za kanema kupanga. Zimakhudza kwambiri momwe zowonera zimawonekera pavidiyo ndipo zitha kugwiritsidwa ntchito kukulitsa mtundu wa zithunzi zamakanema.

Chrominance amatanthauza mtundu, machulukitsidwe, ndi mphamvu wa mitundu mu kanema.

Munkhaniyi, tikambirana mwatsatanetsatane za chrominance ndikuwona gawo lake pakupanga makanema.

Tanthauzo la Chrominance

Chrominance (yomwe imadziwikanso kuti mtundu) ndi chinthu chomwe chimapangidwa pamakanema omwe amawonetsa mtundu wake komanso mawonekedwe ake. Ndi chimodzi mwa zigawo ziwiri za chizindikiro cha kanema, china kukhala chake kuwala (kuwala). Chrominance imayimiridwa ndi mitundu iwiri yamitundu - Cb ndi Cr - zomwe pamodzi zikuyimira phale lapadera poyerekeza ndi kulumikizana kwake ndi Y.

Chrominance ili ndi zambiri za khalidwe, mthunzi, tint ndi kuya kwa mitundu mu kanema kanema. Mwachitsanzo, chrominance ingagwiritsidwe ntchito kulekanitsa khungu ndi mitundu ina pachithunzi pozindikira ma pixel okhala ndi mitundu ina. Mofananamo, chrominance ingagwiritsidwe ntchito kupititsa patsogolo zambiri monga mawonekedwe kapena kusintha kwakung'ono pakuwala, mu digito Makanema, ma chrominance amasungidwa mosiyana ndi makulidwe a kuwala, zomwe zimaloleza kuphatikizika koyenera kwa data popanda kusokoneza mtundu wa chithunzi.

Mbiri ya Chrominance

Chrominancekapena Chroma, ndi chimodzi mwa zigawo ziwiri za utoto zomwe zimagwiritsidwa ntchito popanga makanema (pamodzi ndi kuwala). Imawerengedwa poyesa kukula kwa kuwala pamitundu ina - nthawi zambiri wofiira, wobiriwira ndi wabuluu. Kuwala kwambiri kwa mtundu winawake, m'pamenenso kumakhala ndi chroma.

Teremuyo 'chikondi' idapangidwa koyamba ndi Walter R. Gurney mu 1937 ndipo yakhala yosasinthika kuyambira pamenepo. Kuyambira pamenepo, yakhala ikugwiritsidwa ntchito kwambiri popanga wailesi yakanema monga mitundu yake itatu yayikulu (yofiira, yobiriwira ndi yabuluu) ikufanana kwambiri ndi machubu amtundu wa kanema wawayilesi kuyambira pomwe idakhazikitsidwa. Ngakhale kuti ma TV amakono salinso machubu a cathode-ray ozikidwa pa deta ya chroma ndi luma, makamera ambiri amakono akupitirizabe kugwiritsira ntchito zigawo zimenezi kujambula zithunzi zamitundu.

Chrominance imalola kujambula kolondola kwa mtundu kusiyana ndi zomwe zinalipo kuchokera ku filimu ya monochrome (yakuda ndi yoyera) isanapangidwe kachitidwe kamavidiyo kaphatikizidwe mu 1931. Chrominance nthawi zambiri imayesedwa pogwiritsa ntchito oscilloscope kapena waveform monitor yomwe imasonyeza kusintha kosaoneka bwino kwa milingo yamitundu kumadera onse. ya chithunzi cha kanema - ngakhale zomwe sizikuwoneka ndi maso - kuwonetsetsa kuti mitundu ikukhalabe yosasinthika pakati pa makamera ndi zida panthawi yomwe yapangidwa pambuyo pakupanga monga kusintha ndi encoding pamawonekedwe ogawa digito monga ntchito zotsatsira pa intaneti kapena ma disc media monga Blu-Ray zimbale kapena DVDs.

Zigawo za Chrominance

Chrominance ndi chidziwitso chamtundu mu chithunzi kapena kanema chomwe chimathandiza kupanga chidziwitso chachilengedwe. Chrominance ili ndi zigawo ziwiri: hue ndi kukhuta.

• lokongola ndi mtundu weniweni wa chithunzicho.
• machulukitsidwe ndi kuchuluka kwa mtundu woyera womwe ulipo pachithunzichi.

Zonsezi ndizofunikira pakupanga makanema ndipo tidzakambirana mwatsatanetsatane pansipa.

lokongola

lokongola ndi chimodzi mwa zigawo zomwe zimapanga chrominance. Ndiwo mawu omwe amagwiritsidwa ntchito popanga makanema kuyimira mawonekedwe amtundu motsatira sipekitiramu wofiira mpaka wobiriwira mpaka wabuluu. Mtunduwu umatsimikizira mtundu womwe ulipo komanso momwe ukuwonekera pachithunzichi. Hue ikhoza kuyimiridwa ngati nambala pakati 0 ndi 360 madigiri, 0 kukhala wofiira, 120 kukhala wobiriwira, ndi 240 kukhala buluu. Digiri iliyonse imagawidwa mu increments ya 10, yokhala ndi ma hexadecimal values ​​monga 3FF36F kuyimira mitundu inayake.

Kuphatikiza pa kutanthauzira kwamtundu wa monochrome hue wamayendedwe atatu, makina ena ojambulira amagwiritsa ntchito matanthauzidwe amitundu inayi kapena isanu kuti afotokoze zolondola zamitundu yosiyanasiyana.

machulukitsidwe

machulukitsidwe, nthawi zina amatchedwa chroma or chikondi, ndi gawo la mtundu pakupanga makanema. Machulukidwe amayesa kuchuluka kwa imvi mumtundu. Mwachitsanzo, laimu wobiriwira amakhala ndi machulukitsidwe kwambiri kuposa imvi-wobiriwira; wobiriwira womwewo ukhoza kukhala ndi machulukitsidwe osiyanasiyana malinga ndi momwe amawonekera. Pamene machulukitsidwe akuchulukidwa kwa fano, maonekedwe ake ndi kuwala kwake kumakhala kwakukulu; ikachepa, mtundu ndi kuwala zimachepa.

Mulingo womwe umalongosola kuchuluka kwa machulukitsidwe pachithunzichi umadziwika kuti milingo ya chrominance; izi zikutanthauza ma toni ochokera kukuda (palibe chrominance) kupyola mumitundu yodzaza ndi mphamvu zake zazikulu. Mukasintha magawowa, mutha kusintha mitundu kapena kungowonjezera mitundu mkati mwa chithunzi chanu powonjezera matani ena kapena kupanga kusiyana kwakukulu pakati pa mitundu yakuda ndi yopepuka. Izi zitha kugwiritsidwa ntchito ponseponse pamitundu yonse yachithunzi chanu, kapena kuphwanyidwa ndi kusinthidwa ndi matchanelo amitundu omwe ali ndi gawo lililonse lokhudzidwa la chimango (monga zofiira kapena blues).

Luminance

Kuwala ndi gawo lofunikira la chrominance ndipo limalumikizidwa ndi kawonedwe ka kuwala. Pamalo amtundu uliwonse, kuwala ndizomwe zimayesa momwe zimakhalira chowala kapena chofiyira mtundu winawake umawoneka ngati. Mulingo wa kuwala ukhoza kukhudza momwe zomwe zilimo zimawonekera mosiyanitsa, machulukidwe, ndi mitundu.

Pakupanga makanema, kuwala kumagwira ntchito yofunika kwambiri pakuzindikira kuwala kwa chithunzi. Mwachitsanzo, ngati chithunzi chili ndi kuwala kochulukira, chimaoneka ngati chatsukidwa komanso chosawoneka bwino, pomwe chithunzi chocheperako chidzawoneka chakuda komanso chamatope. Chifukwa chake, opanga makanema amayenera kusintha milingo yowunikira kuti akwaniritse zomwe akufuna pachiwonetsero chilichonse.

Makanema ambiri amakanema amaphatikiza a "luma curve" zomwe zimathandiza akatswiri amakanema kupanga masinthidwe obisika kuti asinthe bwino zithunzi za zida zotulutsa monga zowonera pa TV kapena ma projekita a digito omwe ali ndi mawonekedwe osiyanasiyana omasulira zambiri zamitundu. Ma curve a Luma ali ndi mfundo khumi ndi zisanu ndi imodzi zomwe zikuyimira masitepe 16 ogawidwa mofanana pa sikelo yakuda kwambiri (kuchokera 0-3) mkati mwamtundu wina woyimira ziro wakuda kumanzere ndi woyera kumanja kusonyeza kamvekedwe koyenera pazithunzi zonse mkati mwa ndondomeko kapena pulogalamu. .

Mitundu ya Chrominance

Chrominance ndi mawu omwe amagwiritsidwa ntchito popanga makanema kufotokoza kusiyana pakati pa kuwala ndi chromaticity. Amagwiritsidwa ntchito kuyeza kuchuluka kwa mitundu muvidiyo, komanso angagwiritsidwe ntchito kuzindikira kusintha kwa kuwala ndi mtundu.

Pali mitundu iwiri ya Chrominance: kuwala ndi chikondi. Mtundu uliwonse uli ndi mawonekedwe ake apadera komanso zopindulitsa pakupanga makanema. Tifufuza mitundu iwiriyi m'nkhaniyi.

RGB

RGB (wofiira, wobiriwira, wabuluu) ndi mtundu wamitundu womwe umagwiritsidwa ntchito kwambiri popanga makanema apa digito ndi kapangidwe kake pophatikiza mitundu yoyambirira ya chithunzi kapena kanema. RGB imapanga kuwala koyera kuchokera kumagwero amitundu atatu omwe amaphatikizidwa kuti apange mtengo umodzi. Dongosolo la mitundu imeneyi limapanga mitundu yonga yamoyo mwa kusonyeza unyinji wochuluka wa mitundu pamodzi kuti utsanzire kwambiri zimene zingawonedwe ndi maso a munthu.

Gwero limakhazikitsidwa pogwiritsa ntchito encoder yanjira zitatu kuti ikhale pakati pa machulukitsidwe ndi kuwala, kulola mtundu uliwonse woyambirira (wofiira, buluu ndi wobiriwira) kulamulidwa popanda ena. Ubwino waukulu wa chitsanzo ichi ndi ntchito zake zabwino kwambiri ponena za kuwala ndi kulondola ikafika popanga mitundu yowoneka bwino.

YUV

YUV, yomwe imadziwikanso kuti YCbCr, ndiye kuwala (Y) ndi zigawo ziwiri za chrominance (U ndi V). Zigawo za chrominance za malo amtundu wa digito zimawonetsa kukongola kwa chizindikirocho. YUV, yomwe imagwiritsidwa ntchito kwambiri pojambula zithunzi za digito ndi kujambula mavidiyo, ndi kuphatikiza kwa kuwala ndi zikhalidwe ziwiri za chrominance zomwe zimayimira zizindikiro zosiyana zofiira ndi zabuluu. Dongosololi limalola kuchepetsa zofunikira za bandwidth poyerekeza ndi machitidwe achikhalidwe a RGB pakupanga makanema.

Muchitsanzo cha YUV, chizindikiro chofiira chimayimiridwa ngati "KAPENA" pamene chizindikiro cha buluu chikuyimiridwa ngati "V", pamodzi ndi kuwala (Y). Ma siginecha a U ndi V amachotsedwa pakuwala konseko kuti awonetse zambiri pazithunzi. Kuphatikizira mfundo zitatuzi kumatipatsa mpumulo pa zomwe zimafunikira pa bandwidth pomwe tikusunga mawonekedwe osasinthika panthawi yosunga mavidiyo / kutsitsa.

Mtundu wamtundu wa YUV umathandizidwa ndi makamera ogula ambiri komanso mafayilo azithunzi a JPG omwe amatengedwa ndi mafoni am'manja omwe nthawi zambiri amajambula zithunzi pogwiritsa ntchito mtundu wa YUV asanawakanikize kukhala ma JPEG. Kupitilira apo, mukamatsitsa kapena kuyika zithunzi izi zimathandiza kwambiri chifukwa chidziwitso chocheperako chimafunika kufalitsidwa chifukwa chabwinoko. khalidwe-to-bandwidth ration katundu. Chifukwa cha mawonekedwe awa amakondedwa kuposa RGB pazofalitsa zowulutsira pomwe kutayika kocheperako kungayembekezeredwe chifukwa chake kufunikira kochepa kwa bandwidth potengera njira zama encoding/streaming.

YIQ

YIQ ndi mtundu wa chrominance womwe umagwiritsidwa ntchito ndi makanema akale a analogi a NTSC. Chigawo cha Y chimajambula kuwala kwa chithunzicho, pomwe zigawo za I ndi Q zimagwira mtundu kapena chrominance. Imagwira ntchito polekanitsa mtundu womwe wapatsidwa m'zigawo zake motsatira xy axis, yomwe imadziwikanso kuti Hue (H) ndi Saturation (S). Miyezo ya YIQ imagwiritsidwa ntchito kupanga matrix a RGB omwe amalola kutulutsa kolondola kwamitundu pamakina osiyanasiyana.

YIQ kwenikweni amatenga chizindikiro cha RGB ndikuchigawa m'zigawo zitatu:

• Y (Kuwala)
• I (mtundu wapakati)
• Q (mtundu wa quadrature)

Kusiyanitsa pakati pa magawo apakati ndi ma quadrature ndikosavuta, koma kwenikweni ndimajambula mitundu yoyambirira, pomwe Q imagwira yachiwiri. Zonse pamodzi matchanelo atatuwa amatha kupanga masinthidwe owoneka ngati osatha amtundu, machulukidwe, ndi kuwala komwe kumathandizira owonera kukonzanso zomwe amawonera.

YCbCr

YCbCr (yomwe nthawi zambiri imatchedwa Y'CbCr) ndi mtundu wa chrominance womwe umapangidwa ndi njira zitatu. Njira izi ndi luma (Y), blue-difference chroma (Cb) ndi red-difference chroma (Cr). YCbCr imachokera ku mtundu wa analogi wotchedwa YPbPr, ndikupangitsa kuti ikhale yofanana m'njira zina ndi malo amtundu wa RGB. Ngakhale YCbCr imagwiritsidwa ntchito nthawi zambiri popanga makanema, zithunzi zama digito zitha kusindikizidwa ndi mtundu womwewo.

Lingaliro kumbuyo kwa YCbCr ndikuti limachepetsa kuchuluka kwa deta yomwe ikufunika kuti iwonetsere chithunzi chamtundu. Polekanitsa zidziwitso zosawunikira munjira zina ziwiri, kuchuluka kwa data pachithunzi chonse kumatha kuchepetsedwa kwambiri. Izi zimalola makanema apamwamba kwambiri kapena zithunzi za digito zokhala ndi mafayilo ang'onoang'ono, kupangitsa kuti zikhale zosavuta kusunga ndi kutumiza.

Pofuna kukwaniritsa kuchepetsa uku kwa kukula kwa deta, milingo yolondola yosiyana imagwiritsidwa ntchito pakati pa njira iliyonse. Luma ikhoza kukhala ndi kusintha kwa 8 bits ndi chrominance 4 kapena 5 bits. Kutengera ndi mtundu wanji wa zida zomwe mukugwiritsa ntchito pali magawo angapo omwe alipo, kuphatikiza:

• 4:4:4 ndi 4:2:2 (4 bits pa tchanelo chilichonse),
• 4:2:0 (4 bits for luma, 2 for blue and 2 for red).

Mapulogalamu a Chrominance

Chrominance, ikagwiritsidwa ntchito popanga makanema, imatanthawuza kugwiritsa ntchito kongoletsani muvidiyo. Chrominance ndi chida chofunikira kwambiri popanga zowoneka bwino komanso zowoneka bwino, zomwe zimalola owongolera kuti aziwongolera zomwe zikuchitika komanso momwe akumvera.

Nkhaniyi iwunika njira zosiyanasiyana zomwe chrominance ingagwiritsire ntchito kupanga makanema, kuphatikiza kugwiritsa ntchito:

• Kuyika mitundu
• Color keying
• Mitundu yamitundu

Kukongoletsa Mtundu

Chimodzi mwazinthu zofunika kwambiri pakugwiritsa ntchito chrominance pakupanga makanema ndi kujambula mitundu. Kusankha mitundu ndi njira yowonjezerera chithunzi cha kanema. Monga momwe dzinalo likusonyezera, amagwiritsa ntchito njira zosiyanasiyana kuti asinthe mitundu, ma saturations ndi mikhalidwe ina kuti kuwomberako kuwonekere kapena kuphatikizika mozungulira. Miyezo ya Chrominance ndizofunikira kwambiri panjira iyi, chifukwa zitha kugwiritsidwa ntchito kupanga malingaliro kapena kamvekedwe kake.

Mwachitsanzo, ngati chochitika chakhazikitsidwa m'mphepete mwa nyanja m'bandakucha ndipo chikufunika kukhala ndi kumverera kwamphamvu, milingo ya chrominance imatha kusinthidwa moyenera kuti iwonjezere kuwala kwa dzuwa ndikuwonjezera mithunzi yowoneka bwino ya buluu kuti mumve bwino. Mofananamo, ngati chochitika chikufunika kutengeka kapena sewero, kuchuluka kwa machulukidwe kumatha kuonjezedwa ndikusungabe kukhulupirika kwa chithunzi choyambirira mwakusintha kudzera muzowongolera ma chrominance.

Kusankha mitundu kumathandiza kuwonetsetsa kuti zojambulidwa zonse mkati mwa pulojekiti yomwe mwapatsidwa zimawoneka zofananira malinga ndi matani komanso momwe zimamvekera kuti kusintha ndi kupanga pambuyo pake kukhale bwino.

Kulimbana kwa Mavidiyo

Kuphatikizika kwamakanema ndi njira yochotsera zidziwitso pa kanema wa kanema kuti muchepetse kukula kwa fayilo kapena bandwidth yotumizira. Izi zikuphatikizapo kuchepetsa tsatanetsatane ndi/kapena kusintha kwa kanema aliyense. Chrominance ndizofunikira kwambiri panjirayi chifukwa zimatsimikizira mitundu yamtundu mkati mwa kanema.

Pochepetsa chrominance, kuphatikizika kwamavidiyo kumatha kupanga phindu lalikulu pakusunga deta ndikuwongolera kufalitsa, osakhudza kwambiri khalidwe. Chrominance ingagwiritsidwe ntchito pamitundu yosiyanasiyana ya media, monga kuwulutsa pawailesi yakanema, makanema akukhamukira ndi ma Blu-ray disc.

Pamene chrominance imanyamula zidziwitso zowoneka bwino zomwe timatcha mtundu, kuziyika pang'onopang'ono koma mogwira mtima zimatilola kukakamiza makanema osataya kulondola kwamtundu kapena kutulutsa - zinthu ziwiri zofunika kwambiri pakupanga zowoneka zenizeni. Chrominance imakhudza kuchuluka kwa deta yomwe imafunika kusunga ndi/kapena kutumiza zomvera; pochigwiritsa ntchito mokwanira, tikuwonetsa kukhalabe ochepa posunga a mlingo wapamwamba wa khalidwe mu mawonekedwe athu.

Kukonzekera Makina

Chizindikiro cha chrominance ndi imodzi yomwe imalongosola kuchuluka kwa mtundu wa chifaniziro, osati kuwala. Pakupanga mavidiyo ndi kukonza pambuyo pake, kudziwa bwino bwino kwa chrominance kumaphatikizapo kugwiritsa ntchito mapulogalamu kuti asinthe. kutentha kwamtundu wa chithunzi kapena kanema. Iyi ndi njira yomwe imadziwika kuti kukonzekera mtundu.

Kusintha kwamitundu pakapangidwe kakanema nthawi zambiri kumatanthawuza kusintha kulikonse kwazithunzi zomwe zilipo monga kuchulukitsa kapena kuchepetsa machulukitsidwe, kusintha kuyera bwino, ndikusintha mbali zina zosiyanitsa. Zosinthazi zitha kusintha mawonekedwe a kanema posintha momwe kuwala ndi magawo akuda amaperekera, momwe mitundu imaphatikizidwira, kukula kwamitundu yosiyanasiyana pazithunzi, ndi zina zambiri.

Mwachidule, kusintha kwa chrominance kumagwira ntchito ngati chida choperekera chithunzi chilichonse kamvekedwe ndi malingaliro omwe adakonzedweratu. Kukonza mitundu kumachitika pakakhala mitundu yolakwika kapena yosagwirizana pachithunzipa zomwe zimatha kuyambitsa chisokonezo poyesa kumasulira tanthauzo kapena cholinga chake. Mwachitsanzo, ngati kuyatsa pa seti sikukugwirizana kwenikweni ndi zochitika-ndi-zochitika ndiye izi zitha kubweretsa kusiyana kwa mitundu pakati pa kuwombera kuwiri komwe kumatengedwa mphindi motalikirana. Ndi kusintha kwa chrominance chisokonezo ichi chitha kuchepetsedwa pobweretsa chilichonse kuti chigwirizane nacho chokha - makamaka zokhudza mitundu yake - kotero imawoneka yowala bwino komanso yogwirizana ndi zomwe poyamba zinkaganiziridwa ngati gawo lachindunji chokongoletsera.

Kutsiliza

Mwachidule, chrominance ndi mbali ya mtundu yomwe ingasinthidwe ndikusinthidwa popanga kanema. Chrominance, kapena chroma mwachidule, zimatsimikiziridwa ndi kuyeza hue ndi machulukitsidwe la mtundu kuti lizipatsa mawonekedwe ake apadera. Kuwongolera chrominance ndi chida champhamvu kwa opanga mafilimu, chifukwa amatha kuchigwiritsa ntchito kupanga mawonekedwe a surreal komanso okongola ndi njira zaluso zowunikira.

Pomvetsetsa zoyambira za chrominance, opanga mafilimu amatha kukhala ndi mphamvu zowongolera chilengedwe cha projekiti zawo.

Moni, ndine Kim, mayi komanso wokonda kuyimitsa zoyenda komanso wodziwa zambiri pakupanga media komanso kakulidwe ka intaneti. Ndili ndi chikhumbo chachikulu chojambula ndi makanema ojambula, ndipo tsopano ndikudumphira molunjika kudziko loyimitsa. Ndi blog yanga, ndikugawana zomwe ndaphunzira ndi inu anyamata.