Makina Opangira Mitundu pa Ma TV a LED
Ma TV a LED (Light Emitting Diode) akhala muyezo wagolide wa zida zowonetsera m'nyumba ndi m'malo opezeka anthu ambiri chifukwa amapereka zithunzi zowala, ndi ochepa thupi, osagwiritsa ntchito mphamvu zambiri, komanso otsika mtengo. Ngakhale nthawi zambiri amatchedwa "Ma TV a LED," zida zambirizi kwenikweni ndi ma TV a LCD omwe amagwiritsa ntchito magetsi akumbuyo a LED. Ubwino wa chithunzi chomwe timawona—makamaka kulondola kwa mitundu, kusiyana kwa mitundu, ndi ma gradations—siwumatsimikiziridwa ndi gulu lowonetsera lokha, komanso ndi makina opangira mitundu omwe amagwira ntchito kumbuyo kwa zochitika. Nkhaniyi ikufotokoza momwe utoto pa TV ya LED umakonzedwera kuchokera ku gwero la chizindikiro kuti pamapeto pake uwoneke ngati chithunzi cholemera, chachilengedwe.
1. Kuchokera ku Chizindikiro cha Kanema kupita ku Mtundu Wowoneka
Kwenikweni, wailesi yakanema imalandira chizindikiro cha chithunzi mu mawonekedwe a digito kapena analogi (monga HDMI, mawayilesi a digito, kapena zoulutsira mawu). Chizindikirochi chimakhala ndi chidziwitso cha kuwala (kuwala) ndi chrominance (mtundu), nthawi zambiri mumitundu ngati YCbCr kapena RGB. Deta iyi isanawonetsedwe pazenera, iyenera kukonzedwa ndi purosesa yazithunzi (purosesa yamavidiyo). Purosesa iyi imayang'anira zinthu zambiri: kuchepetsa phokoso, kukulitsa kuthwa, kukulitsa mayendedwe, ndipo chofunika kwambiri pankhaniyi - kusintha mitundu ndi mapu kuti zigwirizane ndi mawonekedwe a gululo.
Mu magwero ambiri a makanema, zambiri za utoto zimayikidwa ndi zitsanzo zochepa, monga 4:2:0, kuti zigwire bwino ntchito. Izi zikutanthauza kuti tsatanetsatane wa utoto umakanikizidwa kuposa tsatanetsatane wa kuwala. Kenako TV imachita chroma upsampling kuti "ibwezeretse" mawonekedwe a utoto, kuletsa chiwonetserocho kuwoneka chojambulidwa ndi zilembo zazing'ono kapena mizere yopyapyala yamitundu.
2. LCD Panel, LED Backlight, ndi Ntchito ya Zosefera za Mitundu
Ma TV a LED nthawi zambiri amagwiritsa ntchito mapanelo a LCD (Liquid Crystal Display). Mapanelo a LCD samatulutsa kuwala okha, koma m'malo mwake amawongolera kuchuluka kwa kuwala kochokera ku LED backlight komwe kumalowetsa. Kuwala kochokera ku backlight iyi nthawi zambiri kumakhala koyera (LED yoyera) kapena kuphatikiza kwapadera kwa spectrum. Kuwalako kumadutsa mu fyuluta yamtundu wa RGB (wofiira, wobiriwira, ndi wabuluu) pa subpixel iliyonse. Kuphatikizika kwa ma subpixel atatuwa kumapanga mitundu yambirimbiri.
Ubwino wa mtundu umakhudzidwa kwambiri ndi:
– Kuwala kwa LED kumbuyo: Kuwala kwa LED "koyera" kwambiri, kumabweretsa mitundu yosiyanasiyana (gamut) yomwe ingapezeke.
- Ubwino wa fyuluta ya utoto: Fyuluta yabwino imatha kupanga utoto wofiira, wobiriwira, ndi wabuluu woyera.
- Kugwira ntchito kwa panel: Kumaphatikizapo kuthekera koletsa kuwala kwa mitundu yakuda komanso kukhazikika kwa ngodya yowonera.
Mu ma TV apakatikati ndi apamwamba, opanga ambiri amagwiritsa ntchito ukadaulo monga Quantum Dot (QLED) kuti awonjezere kuyera kwa kuwala kotero kuti mitundu imakhala yokongola komanso kuti mitundu yosiyanasiyana ikhale yokulirapo.
3. Malo Opaka Mitundu ndi Gamut
Makina okonzera mitundu a pa TV ayenera kusintha chowonetseracho kuti chigwirizane ndi muyezo winawake wa malo amitundu. Miyezo ina yodziwika bwino ndi iyi:
– sRGB / Rec.709: Yodziwika bwino pa ma TV a HD komanso zinthu zambiri za SDR (Standard Dynamic Range).
– DCI-P3: Imagwiritsidwa ntchito kwambiri muzojambula zamakanema ndi zina za HDR.
– Rec.2020: Cholinga cha zinthu za UHD/HDR zomwe zili ndi mitundu yosiyanasiyana, ngakhale kuti si ma TV onse omwe angathe kuchita izi mokwanira.
Zinthu zikafika mu Rec.709, TV imajambula mitundu kuti iwonekere bwino pa panel. Komabe, ngati zomwe zili mkati mwake ndi HDR yokhala ndi cholinga chachikulu cha gamut, TV iyenera kuchita mapping a mitundu kuti igwirizane ndi luso la panel. Ngati mapping awa si olondola, mitundu imatha kuwoneka yodzaza kwambiri kapena yotayidwa.
4. Kuzama kwa Zing'onozing'ono ndi Kugawa Mitundu
Mitundu ya digito imayimiridwa ndi manambala. Kuzama kwa biti kukakwera, kumayenda bwino kwambiri. Ma TV amakono nthawi zambiri amathandizira:
– 8-bit (pafupifupi mitundu 16,7 miliyoni) ya SDR,
- 10-bit (mitundu yoposa 1 biliyoni) ya HDR,
- Palinso gulu la "8-bit + FRC" (Frame Rate Control) lomwe limafanana ndi 10-bit ndi temporal dithering.
Njira yokonzera mitundu imagwiranso ntchito pochepetsa kupendekeka kwa mitundu, mizere yowoneka bwino mumlengalenga kapena mithunzi yofewa. Zinthu monga kupendekeka kwa kuwala ndi kupendekeka kwa kuwala zingathandize kupanga kusintha kwa mitundu kosalala.
5. Kulinganiza Koyera, Kutentha kwa Mtundu, ndi Gamma
Kulondola kwa mitundu sikungokhala kofiira-wobiriwira-buluu, komanso koyenera "koyera." Zoyera zomwe zili zabuluu kwambiri zimapangitsa chithunzicho kuoneka chozizira, pomwe zoyera zomwe zili zachikasu kwambiri zimapangitsa kuti chikhale chofunda. Ma TV nthawi zambiri amapereka mitundu yotenthetsera utoto monga "Kuzizira," "Kwabwinobwino," ndi "Kutentha." Mwachisawawa, poonera makanema ndi zina molondola, cholinga chofanana ndi D65 (pafupifupi 6500K).
Kuphatikiza apo, pali gawo lofunika lotchedwa gamma (ya SDR) kapena transfer curve, monga PQ (ST.2084) ndi HLG (ya HDR). Gamma imalamulira momwe ma midtone amawonetsedwera. Ngati gamma ili yokwera kwambiri, chithunzicho chimawoneka chakuda komanso chosiyana kwambiri; ngati chili chotsika kwambiri, chithunzicho chimawoneka chopanda kanthu.
Dongosolo lokonza mitundu lidzaphatikiza makonda oyera, gamma, ndi kasamalidwe ka mitundu kuti zitsimikizire kuti zotsatira zomaliza zikukwaniritsa miyezo kapena zokonda za ogwiritsa ntchito.
6. Dongosolo Loyang'anira Mitundu (CMS)
Ma TV ambiri amakono amapereka CMS, yomwe ndi njira yosinthira magawo amitundu mwatsatanetsatane, nthawi zambiri imakhala ndi:
– Mtundu (mtundu),
- Kukhuta,
– Kuwala (kuwala kwa mitundu).
CMS imalola kusintha mitundu yoyambirira (RGB) ndi yachiwiri (CMY) kuti igwirizane ndi miyezo yoyerekeza. Pakulinganiza kwaukadaulo, akatswiri amagwiritsa ntchito colorimeter kapena spectroradiometer kuti ayesere kutulutsa kwa gululo, kenako amasintha CMS ndi balance yoyera kuti apeze cholakwika chochepa cha mtundu (Delta E).
7. Kukonza ndi Kujambula Mapu a HDR
HDR (High Dynamic Range) imakulitsa kuwala ndi mitundu, zomwe zimapangitsa kuti kuwala ndi mdima ziwonekere bwino. Komabe, si ma TV onse omwe ali ndi mphamvu zofanana zowunikira. Chifukwa chake, ma TV amachita ma toni: kupanga ma toni a chizindikiro cha HDR, mwina chopangidwira ma nit 1000–4000 (kapena kuposerapo), kuti chigwirizane ndi luso la gululo, monga ma nit 500–1000.
Kujambula ma toni kumagwirizana kwambiri ndi mtundu, chifukwa mu HDR, kuchuluka kwa mitundu nthawi zambiri kumasintha pamene kuwala kukuwonjezeka. Ichi ndichifukwa chake makina opangira mitundu ya HDR ayenera kusunga mitundu yooneka ngati yachilengedwe m'malo owala, kuti isatsukidwe kapena "kutenthedwa."
Mawonekedwe ofala a HDR ndi awa:
– HDR10 (metadata yosasinthika),
- HDR10+ ndi Dolby Vision (dynamic metadata),
– HLG (nthawi zambiri imagwiritsidwa ntchito poulutsa mawu).
Metadata yosinthika imalola TV kusintha mapikidwe a mawu pa chochitika chilichonse kapena pa chimango chilichonse kuti mitundu ndi tsatanetsatane zisungidwe bwino.
8. Kuchepa kwa Maonekedwe a M'deralo ndi Mmene Kumakhudzira Mtundu
Ma TV a LED okhala ndi kuwala kwapafupi (makamaka Full Array Local Dimming/FALD) amatha kuziziritsa madera enaake a kuwala kwakumbuyo kuti awonjezere kusiyana. Komabe, dongosololi limakhudzanso momwe mitundu imaonekera. Ngati njira yoziritsira yakunja ndi yoopsa kwambiri, tsatanetsatane wa mitundu m'malo amdima ukhoza kutayika kapena kuphuka kungachitike (kuwala "kutuluka" mozungulira zinthu zowala). Chifukwa chake, kukonza mitundu ndi kuwongolera kuwala kwakumbuyo kuyenera kugwira ntchito mogwirizana kuti mitundu yowala ikhalebe mumthunzi popanda kuwononga kusiyana.
9. Chithunzi ndi Mtundu wa "Kukoma"
Ma TV ambiri amapereka njira monga Vivid, Standard, Cinema, kapena Filmmaker Mode. Njira yowoneka bwino nthawi zambiri imawonjezera kukhuta, kusiyana, ndi kuthwa kuti iwoneke bwino m'malo ogulitsira owala kwambiri, koma nthawi zambiri imasiya kulondola kwa mitundu. Njira ya Cinema kapena Filmmaker nthawi zambiri imakhala pafupi ndi miyezo yopanga mafilimu ndipo imapereka mitundu yachilengedwe.
Kuphatikiza apo, ma TV ena ali ndi zinthu zina monga "Live Colour," "Color Enhancer," kapena "Dynamic Contrast," zomwe zimasintha mitundu mosavuta. Zinthuzi zitha kukhala zothandiza pazinthu zina, koma kwa ogwiritsa ntchito omwe amayang'ana kwambiri kulondola, nthawi zambiri zimakhala bwino kuzisiya.
10. Kesimpulan
Dongosolo lokonza mitundu mu wailesi yakanema ya LED ndi njira zovuta zomwe zimasintha deta ya kanema kukhala chiwonetsero chabwino, cholondola, komanso chokongola cha mitundu. Kuyambira kusintha mtundu wa mitundu, kupanga ma gamut, makonda oyera, gamma, CMS, mpaka kukonza ma HDR ndi kupanga ma tone—zonsezi zimagwira ntchito pozindikira mtundu wa mawonekedwe. Zotsatira zake zimakhudzidwanso ndi luso la chipangizochi: mawonekedwe a backlight, mtundu wa color filter, kuya kwa panel bit, ndi algorithm ya local dimming.
Kumvetsetsa momwe kukonza mitundu kumagwirira ntchito kumathandiza ogwiritsa ntchito kusankha njira yoyenera yojambulira zithunzi, kupanga makonda odziwa zambiri, kapena ngakhale kusintha kuti apeze mitundu yofanana ndi yomwe ikupezeka. Mwanjira imeneyi, ma TV a LED samangowonetsa zithunzi "zowala", komanso mitundu yowala komanso yolinganizika yomwe ikugwirizana ndi cholinga cha wopanga zomwe zili mkati.
