Chrominance: Menene Yake A cikin Samar da Bidiyo?

da kim An sabunta: Yuni 27, 2022

Chrominance yana daya daga cikin muhimman al'amuran video samarwa. Yana da babban tasiri akan yadda abubuwan gani suke bayyana akan bidiyo kuma ana iya amfani dasu haɓaka ingancin hotunan bidiyo.

Chrominance yana nufin hue, jikewa, da tsanani na launuka a bidiyo.

A cikin wannan labarin, za mu tattauna chrominance daki-daki kuma mu dubi rawar da yake takawa wajen samar da bidiyo.

Ma'anar Chrominance

Chrominance (wanda kuma aka sani da launi) shine ɓangarorin samar da bidiyo wanda ke ba da launi da saturation na hoton. Yana daya daga cikin abubuwa biyu na siginar bidiyo, ɗayan kuma shine nata luminance (haske). Chrominance yana wakilta da daidaitawar launi guda biyu - Cb da Cr - wanda tare ke wakiltar palette mai launi na musamman idan aka kwatanta da daidaitawar hasken sa na Y.

Chrominance ya ƙunshi bayanai game da inganci, inuwa, tint da zurfin launuka a cikin siginar bidiyo. Misali, ana iya amfani da chrominance don raba sautunan fata daga wasu launuka a cikin hoto ta hanyar gano pixels tare da wasu ƙimar launi. Hakanan, ana iya amfani da chrominance don haɓaka cikakkun bayanai kamar laushi ko ƙananan bambance-bambance a cikin haske. a digital Tsarin bidiyo, chrominance ana adana shi daban daga ƙimar haske, yana ba da damar ƙarin ingantaccen matse bayanai ba tare da lalata ingancin hoto ba.

Tarihin Chrominance

Chrominance, ko Chroma, yana ɗaya daga cikin sassa biyu na launi da ake amfani da su wajen samar da bidiyo (tare da haske). Ana ƙididdige shi ta hanyar auna ƙarfin haske a wasu launuka - sau da yawa ja, kore da shudi. Da haske na musamman ya zama, ƙarin chroma yana da.

Ajalin 'chrominanceWalter R. Gurney ne ya fara kirkiro shi a cikin 1937 kuma ya kasance baya canzawa tun lokacin. Tun daga wannan lokacin, ana amfani da shi sosai a cikin samar da talabijin kamar yadda launukansa na farko guda uku (ja, kore da shuɗi) suka yi daidai da na bututun kalar talabijin tun farkonsa. Yayin da talabijin na yau ba su da bututun cathode-ray dangane da bayanan chroma da luma, yawancin kyamarori na zamani suna ci gaba da amfani da waɗannan abubuwan don yin rikodin hotuna masu launi.

Chrominance yana ba da damar ingantaccen rikodin launi fiye da abin da yake samuwa daga fim ɗin monochrome (baki da fari) kafin haɓaka tsarin tsarin bidiyo mai haɗaka a cikin 1931. Yawancin lokaci ana auna chrominance ta amfani da oscilloscope ko na'ura mai saka idanu wanda ke gano canje-canje na dabara a cikin matakan launi a duk sassa. na hoton bidiyo - har ma da waɗanda ba a iya gani da ido tsirara - tabbatar da cewa launuka sun kasance daidai tsakanin kyamarori da na'urori yayin aiwatar da ayyukan bayan samarwa kamar gyare-gyare da ɓoye don tsarin rarraba dijital kamar sabis na yawo na intanet ko kafofin watsa labaru kamar su. Blu-ray fayafai ko DVD.

Abubuwan da ke cikin Chrominance

Chrominance shine bayanin launi a cikin hoto ko bidiyo wanda ke taimakawa haifar da ma'anar halitta. Chrominance ya ƙunshi abubuwa biyu: hue da kuma jikewa.

• Ya dafa shine ainihin launi na hoton.
• Jikewa shine adadin tsarkakakken launi da ke cikin hoton.

Dukansu abubuwa ne masu mahimmanci na samar da bidiyo kuma za a tattauna su dalla-dalla a ƙasa.

Ya dafa

Ya dafa yana daya daga cikin abubuwan da suka hada da chrominance. Kalmar da ake amfani da ita wajen samar da bidiyo don wakiltar matsayin launi tare da bakan daga ja zuwa kore zuwa shuɗi. Hoton yana ƙayyade ko wane launi yake da kuma yadda cikakken satut yake bayyana a hoto. Ana iya wakilta Hue azaman lamba tsakanin 0 da 360 digiri, tare da 0 yana ja, 120 kore ne, 240 kuma shuɗi ne. Kowane digiri ya kasu kashi 10, tare da ƙimar hexadecimal kamar 3FF36F wakiltar launuka na musamman.

Baya ga ma'anar hue mai tashoshi uku na gargajiya, wasu tsarin hoto suna amfani da ma'anar hue-hudu ko biyar don ƙarin ingantattun kwatancen bambancin hue.

Jikewa

Jikewa, wani lokacin ana magana da shi chroma or chrominance, wani bangare ne na launi a cikin samar da bidiyo. Saturation yana auna adadin launin toka a cikin launi. Alal misali, koren lemun tsami yana da ƙarin jikewa fiye da launin toka-kore. Koren iri ɗaya na iya samun saturation daban-daban dangane da yadda haske ya bayyana. Lokacin da aka ƙara jikewa don hoto, launinsa da haskakarsa suna ƙara ƙarfi; idan ya ragu, launi da haske suna raguwa.

Ma'aunin da ke bayyana matakin jikewa a cikin hoto an san shi da matakan chrominance; wannan yana nufin sautuna daga baki (babu chrominance) ta hanyar zuwa cikakkun launuka masu haske a iyakar ƙarfinsu. Ta hanyar daidaita waɗannan matakan za ku iya yin gyare-gyaren launi ko kawai haɓaka launuka a cikin hotonku ta ƙara wasu sautuna ko ƙirƙirar babban bambanci tsakanin duhu da haske. Ana iya amfani da wannan a ko'ina cikin duk launukan da ke cikin hotonku, ko rushewa da daidaita su ta takamaiman tashoshi masu launi waɗanda suka ƙunshi kowane yanki da abin ya shafa na firam ɗin (kamar ja ko blue).

Luminance

Luminance wani muhimmin sashi ne na chrominance kuma yana da alaƙa da tsinkayen haske. A kowane sarari launi da aka ba, haske shine ma'aunin ma'auni na yadda wani launi mai haske ko maras kyau ya bayyana. Matsayin haske na iya rinjayar yadda abun ciki ya bayyana cikin sharuɗɗan bambanci, jikewa, da matakan launi.

A cikin samar da bidiyo, haskakawa yana taka muhimmiyar rawa wajen tantancewa haske na hoto. Misali, idan hoton yana da girman haske fiye da kima, zai bayyana an wanke shi kuma ya dushe, yayin da hoton da yake da ƙarancin haske zai bayyana ya fi duhu da laka. Don haka, masu yin bidiyo dole ne su daidaita matakan haske don cimma sakamakon da ake so don kowane yanayi.

Yawancin ayyukan aikin bidiyo sun haɗa da a "luma curve" wanda ke ba da damar ƙwararrun bidiyo don yin gyare-gyare masu sauƙi don daidaita hotuna masu kyau don na'urorin fitarwa kamar allon talabijin ko na'urorin dijital waɗanda ke da halaye daban-daban don fassarar bayanin launi. Luma masu lankwasa sun ƙunshi maki goma sha shida waɗanda ke wakiltar matakai 16 da aka raba daidai da ma'aunin haske-Duhu (daga 0-3) a cikin kewayon kewayon ke wakiltar sifili baƙar fata a hagu da fari a gefen dama yana nuna daidaitaccen sautin gabaɗayan hotuna a cikin jeri ko shirin. .

Nau'in Chrominance

Chrominance kalma ce da ake amfani da ita wajen samar da bidiyo don bayyana bambanci tsakanin haske da chromaticity. Ana amfani da shi don auna saturation na launuka a cikin bidiyo, kuma ana iya amfani da shi don gano canje-canje a haske da launi.

Akwai nau'ikan Chrominance guda biyu: luminance da kuma chrominance. Kowane nau'in yana da nasa halaye na musamman da fa'idodi don samar da bidiyo. Za mu bincika iri biyu a cikin wannan labarin.

RGB

RGB (ja, kore, blue) samfuri ne mai launi da aka yi amfani da shi da yawa a cikin samar da bidiyo na dijital da ƙira yayin haɗa launuka na farko don hoto ko bidiyo. RGB yana ƙirƙirar farin haske daga maɓuɓɓugar haske masu launi uku waɗanda aka haɗa don ƙirƙirar katako guda ɗaya. Wannan tsarin launi yana haifar da launuka masu kama da rai ta hanyar nuna matsakaicin adadin launuka tare don yin koyi da abin da idon ɗan adam zai iya gani sosai.

An saita tushen ta amfani da mai rikodin tashoshi uku don daidaitawa tsakanin jikewa da haske, ƙyale kowane launi na farko (ja, blue da kore) a sarrafa ba tare da sauran ba. Babban fa'idar wannan ƙirar ita ce ƙwararren aikin sa dangane da haske da daidaito idan ya zo ga samar da launuka masu haske.

YUV

YUV, wanda kuma aka sani da YCbCr, shine hasken (Yda kuma nau'ikan chrominance guda biyu (U da kuma V). Abubuwan chrominance na sararin launi na dijital suna nuna yadda siginar ke da launi. YUV, wanda aka saba amfani dashi a cikin daukar hoto na dijital da faifan bidiyo, haɗin haske ne da ƙimar chrominance guda biyu waɗanda ke wakiltar siginar bambance-bambance na ja da shuɗi. Wannan tsarin yana ba da damar rage buƙatun bandwidth idan aka kwatanta da sarrafa siginar RGB na gargajiya a cikin samar da bidiyo.

A cikin ƙirar YUV, ana wakilta siginar ja azaman "KO" yayin da siginar blue ke wakilta kamar "V", tare da haske (Y). Ana cire siginar U da V daga hasken gaba ɗaya don wakiltar cikakkun bayanai masu launi a hoto. Haɗa waɗannan dabi'u guda uku yana ba mu sauƙi akan buƙatun bandwidth yayin da muke kiyaye ingancin inganci yayin aiwatar da rikodin bidiyo / yawo.

Tsarin launi na YUV yana samun tallafi ta asali ta yawancin kyamarorin bidiyo na mabukaci da kuma fayilolin hoton JPG waɗanda wayoyin hannu suka ɗauka waɗanda galibi suna ɗaukar hotuna ta amfani da tsarin YUV kafin matsa su cikin JPEGs. A ƙasan layi, lokacin yawo ko ɓoye waɗannan hotuna yana taimakawa sosai tunda ƙaramin bayanai yana buƙatar watsawa saboda mafi kyawun sa. Properties rabon ingancin-zuwa-bandwidth. Saboda waɗannan halayen an fi son RGB don dalilai na watsa shirye-shirye inda za a iya sa ran asarar ƙarancin inganci saboda ta ƙananan buƙatun bandwidth lokacin da ake karɓa don tsarin ɓoyewa / yawo.

YIQ

YIQ wani nau'in chrominance ne da aka saba amfani da shi tare da tsofaffin tsarin bidiyo na analog na NTSC. Bangaren Y yana ɗaukar hasken hoton, yayin da abubuwan I da Q suna ɗaukar launi ko chrominance. Yana aiki ta hanyar rarraba wani launi da aka ba da shi cikin sassansa tare da axis xy, in ba haka ba da aka sani da Hue (H) da Saturation (S). Ana amfani da ƙimar YIQ don samar da matrix na RGB wanda ke ba da damar ƙarin ingantaccen haifuwar launi akan tsarin daban-daban.

YIQ da gaske yana ɗaukar siginar RGB kuma ya raba shi zuwa sassa uku:

• Y (haske)
• I (launi a cikin lokaci)
• Q (launi huɗu)

Bambance-bambancen da ke tsakanin in-phase da quadrature ɓangarorin suna da dabara, amma da gaske na ɗauki nau'i biyu na launuka na farko, yayin da Q ya ɗauki nau'i na biyu. Tare waɗannan tashoshi guda uku suna da ikon ƙirƙirar bambance-bambance masu kama da ƙarewa cikin launi, jikewa, da haske waɗanda ke baiwa masu kallo damar sake ƙirƙira nasu ƙwarewar kallo.

YCbCr

YCbCr (wanda aka fi sani da Y'CbCr) wani nau'in chrominance ne wanda ya ƙunshi tashoshi uku. Wadannan tashoshi sune luma (Y), chroma blue-bambanci (Cb) da kuma chroma ja-bambanci (Cr). YCbCr ya dogara ne akan nau'in analog mai suna YPbPr, yana mai da shi kama da wasu hanyoyi zuwa sararin launi na RGB. Kodayake ana amfani da YCbCr sau da yawa wajen samar da bidiyo, ana iya sanya hotunan dijital da tsari iri ɗaya.

Manufar da ke bayan YCbCr ita ce tana rage adadin bayanan da ake buƙata don wakiltar hoton launi. Ta hanyar keɓance bayanan da ba su da haske zuwa wasu tashoshi biyu, ana iya rage jimillar adadin bayanai na hoto gaba ɗaya. Wannan damar don bidiyo mai inganci ko hotuna na dijital tare da ƙananan girman fayil, yana sauƙaƙa adanawa da watsawa.

Don cimma wannan raguwar girman bayanai, ana amfani da matakan daidaito daban-daban tsakanin kowane tashoshi. Luma na iya samun ƙuduri na 8 bits da chrominance 4 ko 5 bits. Dangane da nau'in kayan aikin da kuke amfani da su akwai matakai da yawa da ake samu, gami da:

• 4:4:4 da kuma 4:2:2 (4 bits ga kowane tashar),
• 4:2:0 (4 ragowa don luma, 2 na shuɗi da 2 don ja).

Aikace-aikace na Chrominance

Chrominance, lokacin da aka yi amfani da shi wajen samar da bidiyo, yana nufin amfani da launi a cikin bidiyo. Chrominance kayan aiki ne mai mahimmanci don ƙirƙirar bayyananniyar gani da gani, kyale daraktoci don haɓaka yanayi da motsin zuciyar wurin.

Wannan labarin zai bincika hanyoyi daban-daban waɗanda za a iya amfani da chrominance wajen samar da bidiyo, gami da amfani da:

• Ƙididdigar launi
• Maɓallin launi
• Launuka masu launi

Girman Launi

Ɗaya daga cikin mahimman aikace-aikacen chrominance a cikin samar da bidiyo shine launi. Girman launi hanya ce ta haɓaka hoton bidiyo. Kamar yadda sunan ke nunawa, yana amfani da dabaru daban-daban don daidaitawa launuka, saturation da sauran halaye don sanya harbi ya yi fice ko ya gauraya cikin kewayensa. Matakan chrominance suna da mahimmanci musamman ga wannan tsari, saboda ana iya amfani da su don ƙirƙirar wani yanayi ko sauti.

Misali, idan an saita wuri ta bakin teku da wayewar gari kuma yana buƙatar samun jin daɗi, ana iya daidaita matakan chrominance daidai don haɓaka hasken rana mai dumi da ƙara inuwar shuɗi don jin iska. Hakazalika, idan yanayin yana buƙatar ƙarin motsin rai ko wasan kwaikwayo, ana iya ƙara matakan jikewa yayin da ake ci gaba da kiyaye amincin ainihin hoton hoto ta hanyar daidaitawa ta hanyar sarrafa chrominance.

Ƙididdigar launi yana taimakawa tabbatar da cewa duk hotuna a cikin aikin da aka bayar sun bayyana daidai cikin sharuddan sautuna da ji ta yadda gyarawa da haɓakawa ke tafiya cikin santsi.

Video matsawa

Matsawar bidiyo shine tsarin cire bayanai daga siginar bidiyo don rage girman fayil ko bandwidth watsawa. Wannan ya ƙunshi rage daki-daki da/ko ƙudurin kowane bidiyo da aka bayar. Chrominance yana da mahimmanci musamman ga wannan tsari yayin da yake ƙayyade abubuwan launi a cikin siginar bidiyo.

Ta hanyar rage chrominance, damfara bidiyo na iya samun gagarumar nasara ta fuskar adana bayanai da daidaitawa, tare da ɗan ƙaramin tasiri akan inganci. Ana iya amfani da Chrominance zuwa nau'ikan kafofin watsa labaru daban-daban, kamar watsa shirye-shiryen talabijin, bidiyo mai yawo da fayafai na Blu-ray.

Kamar yadda chrominance ke ɗauke da mahimman bayanan gani da muke kira launi, ɓoye shi cikin ɗan lokaci amma yadda ya kamata ya ba mu damar damfara bidiyo ba tare da sadaukar da daidaiton launi ko jikewa ba - abubuwa biyu masu mahimmanci wajen ƙirƙirar. abubuwan gani na zahiri. Chrominance yana rinjayar adadin bayanai da ake buƙata don adanawa da/ko watsa abun ciki mai jiwuwa; ta hanyar yin cikakken amfani da shi, muna nuna zama kaɗan yayin da muke riƙe da a babban matakin inganci a cikin abubuwan da muke gani.

Ƙirƙirar Launi

Alamar chrominance shine wanda ke bayyana adadin launi a cikin hoto, maimakon haske. A cikin samar da bidiyo da aiwatarwa bayan aiki, ƙayyade ma'aunin chrominance mai nasara ya haɗa da amfani da software don daidaitawa zafin launi na hoto ko fim. Wannan tsari ne da aka sani da gyaran launi.

gyare-gyaren launi a cikin bidiyo bayan samarwa sau da yawa yana nufin kowane canji na hotunan da ke akwai kamar karuwa ko rage jikewa, daidaita ma'auni na fari, da canza wasu nau'ikan bambanci. Waɗannan gyare-gyare na iya canza kamannin fim ɗin sosai ta hanyar canza yadda ake yin haske da sassa masu duhu, yadda launuka ke gauraye da juna, tsananin launuka daban-daban a cikin abubuwan gani, da ƙari.

A takaice, daidaitawa ga chrominance yana aiki azaman kayan aiki don ba kowane yanayi sauti da yanayin da aka ƙaddara. Gyaran launi yawanci yana faruwa ne lokacin da launuka marasa daidai ko rashin daidaituwa a cikin hoto wanda zai iya haifar da rudani yayin ƙoƙarin fassara ma'anarsa ko manufarsa. Misali, idan hasken wuta akan saitin bai yi daidai ba daga fage-zuwa-bangaren to wannan na iya haifar da bambance-bambancen launuka tsakanin harbe-harbe guda biyu da aka dauki mintuna ban da juna. Tare da gyare-gyaren chrominance wannan rikicewar za a iya ragewa ta hanyar dawo da komai cikin jituwa tare da kanta - musamman game da launukansa - don haka ya bayyana da kyau da kyau kuma ya yi daidai da abin da aka fara hasashe a matsayin wani ɓangare na manufar ƙayataccen yanki.

Kammalawa

Don taƙaitawa, chrominance wani bangare ne na launi wanda za'a iya canza shi da sarrafa shi lokacin samar da bidiyo. Chromance, ko chroma a takaice, an ƙaddara ta hanyar aunawa launi da jikewa na launi don ba shi kamanninsa na musamman. Yin amfani da chrominance kayan aiki ne mai ƙarfi ga masu yin fim, saboda suna iya amfani da shi don ƙirƙirar surreal da kyawawan al'amuran tare da ƙwararrun dabarun haske.

Ta hanyar fahimtar mahimmancin chrominance, masu yin fina-finai na iya samun ƙarin ikon sarrafawa akan yanayin ayyukan su.

Barka dai, Ni Kim, mahaifiya ce kuma mai sha'awar tsayawa motsi tare da kwarewa a ƙirƙirar kafofin watsa labarai da haɓaka yanar gizo. Ina da sha'awar zane da raye-raye, kuma yanzu na fara nutsewa a cikin duniyar tasha-motsi. Tare da bulogi na, Ina raba abubuwan da na koya tare da ku mutane.