Chrominance: Chii Chiri Mukugadzira Vhidhiyo?

by kim Updated: June 27, 2022

Chrominance ndechimwe chezvinhu zvakakosha zve Video production. Iyo ine simba guru pamabatirwo anoonekwa pavhidhiyo uye inogona kushandiswa kuwedzera kunaka kwemifananidzo yemavhidhiyo.

Chrominance inoreva iyo hue, saturation, uye kusimba ye mavara muvhidhiyo.

Muchikamu chino, tichakurukura chrominance zvakadzama uye titarise basa rayo mukugadzira vhidhiyo.

Tsanangudzo yeChrominance

Chrominance (inozivikanwawo seruvara) chinhu chekugadzirwa kwevhidhiyo chinoburitsa hue uye kuzara kwemufananidzo. Icho chimwe chezvikamu zviviri zvechiratidzo chevhidhiyo, imwe yacho iri yayo luminance (kupenya). Chrominance inomiririrwa nemavara maviri ekuronga - Cb uye Cr - iyo pamwe chete inomiririra yakasarudzika pendi yeruvara mukuenzanisa neyayo kupenya kurongeka Y.

Chrominance ine ruzivo nezve kunaka, mumvuri, tint uye kudzika kwemavara muchiratidzo chevhidhiyo. Semuenzaniso, chrominance inogona kushandiswa kupatsanura matani eganda kubva kune mamwe mavara mumufananidzo nekuzivisa mapixel ane mamwe mavara emhando. Saizvozvo, chrominance inogona kushandiswa kuwedzera ruzivo senge mavara kana misiyano midiki mukupenya, mu digitaalinen mavhidhiyo mafomati, chrominance inochengetwa yakaparadzana kubva kumararamiro ekuvhenekera, zvichibvumira kudzvanya kwakanyanya kwedata pasina kukanganisa pamhando yemifananidzo.

Nhoroondo yeChrominance

Chrominance, kana Chroma, ndechimwe chezvikamu zviviri zvemavara zvinoshandiswa mukugadzirwa kwevhidhiyo (pamwe neruvheneko). Inoverengwa nekuyera kusimba kwechiedza pane mamwe mavara - kazhinji tsvuku, girini uye bhuruu. Kujeka kweimwe hue inova, iyo inowedzera chroma iyo ine.

Izwi rekuti 'chrominance' yakatanga kugadzirwa naWalter R. Gurney muna 1937 uye yakaramba isina kushanduka kubva ipapo. Kubva ipapo, yakashandiswa zvakanyanya mukugadzirwa kweterevhizheni semavara ayo matatu ekutanga (tsvuku, girinhi nebhuruu) achinyatsoenderana neaya eterevhizheni mavara machubhu kubvira payakavambwa. Nepo materevhizheni emazuva ano haasisiri machubhu e<em>cathode-ray akavakirwa pa<em>chroma ne<em>luma mashoko, makamera akawanda emazuva ano anopfuurira kushandisa zvinhu izvi kurekodha mifananidzo yeruvara.

Chrominance inobvumira kurekodha kwakaringana kweruvara kupfuura izvo zvaivepo kubva kumonochrome (dema nechena) firimu kusati kwave nekugadzirwa kweanosanganiswa mavhidhiyo masisitimu muna 1931. Chrominance inowanzoyerwa pachishandiswa oscilloscope kana waveform monitor inoratidza kushanduka kusinganzwisisike kwemavara emavara munzvimbo dzese. yemufananidzo wevhidhiyo - kunyangwe iwo asingaonekwe neziso rakashama - kuve nechokwadi chekuti mavara anoramba achienderana pakati pemakamera nemidziyo panguva yekumashure-yekugadzira maitiro sekugadzirisa uye encoding yemafomati ekuparadzira edhijitari senge internet yekufambisa masevhisi kana disc media senge. Blu-Ray discs kana maDVD.

Zvikamu zveChrominance

Chrominance irwo ruzivo rweruvara mumufananidzo kana vhidhiyo inobatsira kugadzira pfungwa yekusikwa. Chrominance inosanganisira zvikamu zviviri: hue uye kuzadza.

• Hue ndiwo chaiwo ruvara rwemufananidzo.
• Saturation chiyero chemavara akachena aripo mumufananidzo.

Ose ari maviri akakosha maficha ekugadzirwa kwevhidhiyo uye achakurukurwa zvakadzama pazasi.

Hue

Hue chimwe chezvikamu zvinoumba chrominance. Ndiro izwi rinoshandiswa mukugadzirwa kwevhidhiyo kumiririra chinzvimbo cheruvara pamwe nechero spectrum kubva tsvuku kusvika kugirinhi kusvika kubhuruu. Iyo hue inosarudza kuti ndeupi ruvara rwuripo uye kuti yakazara sei mumufananidzo. Hue inogona kumiririrwa senhamba pakati 0 uye 360 madhigirii, 0 ari mutsvuku, 120 ari girinhi, uye 240 ari bhuruu. Dhigirii rega rega rakakamurwa kuita maincrements egumi, ane hexadecimal values ​​senge 3FF36F inomiririra mamwe mavara.

Pamusoro pechinyakare chetatu-channel monochrome hue tsananguro, mamwe masisitimu ekufungidzira anoshandisa ina- kana shanu-chaneru hue tsananguro kune dzakanyatsorongeka tsananguro yekusiyana kwemavara.

Saturation

Saturation, dzimwe nguva kunonzi chroma or chrominance, chikamu chemavara mukugadzirwa kwevhidhiyo. Saturation inoyera huwandu hwegrey muruvara. Semuenzaniso, lime yegirini ine zvakawanda saturation kupfuura greyish-girini zvingadaro; girini imwe cheteyo inogona kuve nekuzara kwakasiyana zvichienderana nekupenya kwayo. Kana saturation ichiwedzerwa kumufananidzo, hue uye kupenya kwayo kunowedzera kusimba; kana yadzikira, hue uye kupenya kunoderera.

Chikero chinotsanangura chiyero chekuzara mumufananidzo chinozivikanwa se chrominance levels; izvi zvinoreva toni kubva mutema (hapana chrominance) kusvika kumavara akazara pakusimba kwawo. Nekugadzirisa mazinga aya, unokwanisa kugadzirisa mavara kana kungo wedzera mavara mukati memufananidzo wako nekuwedzera mamwe toni kana kugadzira musiyano wakafara pakati perima nechiedza. Izvi zvinogona kuiswa pasi rose pamavara ese ari mumufananidzo wako, kana kuputswa nekugadziridzwa nemachaneli eruvara anosanganisira chero nzvimbo yakapihwa yakakanganisika yefuremu (senge zvitsvuku kana zvitema).

Luminance

Luminance chinhu chakakosha chechrominance uye inosanganiswa nekuona kwekupenya. Mune chero yakapihwa nzvimbo yeruvara, luminance ndiyo inomiririra chiyero chekuti sei kupenya kana kugomara rumwe ruvara runoratidzika kuva. Chiyero chekupenya chinogona kukanganisa kuti zvirimo zvinoonekwa sei maererano nekusiyanisa, saturation, uye mazinga eruvara.

Mukugadzira vhidhiyo, luminance inoita basa rakakosha pakusarudza iyo kupenya kwechifananidzo. Semuyenzaniso, kana chifananidzo chiine kupenya kwakanyanya, chinozoonekwa chasukwa uye chisina kujeka, nepo chifananidzo chine kupenya kwakaderera chichizooneka chakasviba uye chine madhaka. Saka nekudaro, vagadziri vevhidhiyo vanofanirwa kugadzirisa mazinga ekuvhenekera kuti vawane mhedzisiro inodiwa kune yega yega chiitiko.

Mazhinji mavhidhiyo workflows anosanganisira a "Luma curve" izvo zvinobvumira nyanzvi dzevhidhiyo kuti dzigadzirise zvinyoro-nyoro kugadziridza zvakanaka mifananidzo yezvishandiso zvinobuda sezvikirini zveterevhizheni kana mapurojekita edhijitari ane maitiro akasiyana ekududzira ruzivo rwemavara. Luma curves inoumbwa nemapoinzi gumi nematanhatu anomiririra nhanho gumi nenhanhatu dzakapatsanurwa zvakaenzana pachiyero-chakasviba (kubva pa16-0) mukati meimwe nzvimbo inomiririra zero nhema kuruboshwe uye chena kudivi rekurudyi zvichiratidza kurongeka kwese kwese kwemifananidzo mukati mekutevedzana kwese kana chirongwa. .

Mhando dzeChrominance

Chrominance ishoko rinoshandiswa mukugadzira vhidhiyo kutsanangura mutsauko uripo pakati pechiedza uye chromaticity. Inoshandiswa kuyera kuzara kwemavara muvhidhiyo, uye inogona zvakare kushandiswa kuona shanduko mukupenya uye ruvara.

Kune marudzi maviri eChrominance: luminance uye chrominance. Mhando yega yega ine yayo yakasarudzika maitiro uye mabhenefiti ekugadzirwa kwevhidhiyo. Tichaongorora marudzi ese ari maviri muchinyorwa chino.

RGB

RGB (tsvuku, girini, bhuruu) imhando yemavara inoshandiswa zvakanyanya mukugadzirwa kwevhidhiyo yedhijitari uye dhizaini kana uchibatanidza mavara ekutanga emufananidzo kana vhidhiyo. RGB inogadzira mwenje chena kubva kune matatu mavara emwenje masosi anosanganiswa kugadzira danda rimwe chete. Iyi gadziriro yeruvara inogadzira mavara akafanana nehupenyu nekuratidzira huwandu hwehuwandu hwemavara pamwe chete kuti vatevedzere zvakanyanya sezvinobvira izvo zvinogona kuonekwa neziso remunhu.

Iyo sosi inomisikidzwa uchishandisa matatu-channel encoder yekuenzanisa pakati pekuzadza uye kupenya, ichibvumira yega yega yekutanga ruvara (tsvuku, bhuruu uye girini) kudzorwa pasina vamwe. Kubatsira kukuru kweiyo modhi ndiko kuita kwayo kunoshamisa maererano ne kupenya uye nemazvo kana zvasvika pakuburitsa mavara anoyevedza.

YUV

YUV, inozivikanwawo seYCbCr, ndiyo inopenya (Y) uye zvikamu zviviri zvechrominance (U uye V) Izvo zvikamu zvechrominance zvenzvimbo yemavara edhijitari zvinoratidza kuti chiratidzo chine mavara sei. YUV, inowanzoshandiswa mukutora mafoto edhijitari uye kutora vhidhiyo, musanganiswa wekupenya uye maviri chrominance hunhu hunomiririra misiyano masiginecha kune tsvuku nebhuruu. Iyi sisitimu inobvumira kuderedzwa bandwidth zvinodiwa zvichienzaniswa neyechinyakare RGB chiratidzo chekugadzirisa mukugadzirwa kwevhidhiyo.

Mumuenzaniso weYUV, chiratidzo chitsvuku chinomiririrwa se "KANA" nepo chiratidzo chebhuruu chichimiririrwa se "V", pamwe chete nechiedza (Y) Iwo maU uye V masaini anobviswa kubva pakupenya kwese kuti amiririre mavara ane mavara mumufananidzo. Kubatanidza izvi zvitatu zvakakosha zvinotipa zororo pane bandwidth inodiwa tichichengeta mhando yakasimba panguva yevhidhiyo encoding / kuyerera maitiro.

YUV color fomati inotsigirwa neakawanda evatengi vhidhiyo makamera pamwe neJPG mafaera emifananidzo anotorwa nenharembozha ayo anowanzo kutora mafoto achishandisa YUV fomati isati yaamanikidza muJPEGs. Kuenderera mberi pasi pemutsara, kana uchitenderera kana kukodha mifananidzo iyi inobatsira zvakanyanya sezvo data shoma ichida kufambiswa nekuda kwekunaka kwayo. kunaka-kune-bandwidth ration zvivakwa. Nekuda kwehunhu uhu inofarirwa pamusoro peRGB nekuda kwenhepfenyuro uko kurasikirwa kwemhando kushoma kunogona kutarisirwa nekuda kwayo yakaderera bandwidth chinodiwa painogamuchirwa kune encoding / kuyerera maitiro.

YIQ

YIQ imhando yechrominance inowanzo shandiswa neyekare NTSC analog vhidhiyo mafomati. Iyo Y chikamu chinotora kupenya kwemufananidzo, nepo I uye Q zvikamu zvinotora ruvara kana chrominance. Inoshanda nekuparadzanisa ruvara rwakapihwa muzvikamu zvaro pamwe neiyo xy axis, neimwe inozivikanwa seHue (H) yayo uye Saturation (S). Iyo YIQ tsika dzinobva dzashandiswa kugadzira RGB matrix iyo inobvumira kunyatsoita kubereka kwemavara pane akasiyana masisitimu.

YIQ inonyatso inotora chiratidzo cheRGB uye ichitsemura kuita zvinhu zvitatu:

• Y (Chiedza)
• I (mu-chikamu ruvara)
• Q (quadrature color)

Misiyano pakati pe-mu-chikamu uye quadrature zvikamu zvidiki, asi chaizvo ini ndinotora peya imwe yemavara ekutanga, nepo Q inotora peya yechipiri. Pamwe chete aya machanera matatu anokwanisa kugadzira misiyano inoita senge isingaperi muhue, saturation, uye kupenya izvo zvinoita kuti vataridzi vagadzire zvakare yavo yemunhu maonero ekuona.

YCbCr

YCbCr (inowanzo kunzi Y'CbCr) imhando yechrominance iyo inoumbwa nematanho matatu. Zviteshi izvi simba (Y), blue-difference chroma (Cb) uye red-difference chroma (Cr). YCbCr yakavakirwa pane analog vhezheni inonzi YPbPr, ichiita kuti ive yakafanana mune dzimwe nzira kune RGB ruvara nzvimbo. Kunyangwe YCbCr ichinyanya kushandiswa mukugadzira vhidhiyo, mifananidzo yedhijitari inogona kuvharirwa nefomati imwechete.

Pfungwa iri kuseri kweYCbCr ndeyekuti inoderedza huwandu hwe data inodiwa kumiririra mufananidzo weruvara. Nekuparadzanisa ruzivo rwusiri rweruvheneko mune mamwe maviri chiteshi, huwandu hwe data hwemufananidzo wese hunogona kuderedzwa zvakanyanya. Izvi zvinobvumira vhidhiyo yemhando yepamusoro kana mifananidzo yedhijitari ine masaizi madiki efaira, zvichiita kuti zvive nyore kuchengeta uye kutumira.

Kuti uwane kuderedzwa uku kwehukuru hwe data, mazinga akasiyana ekururama anoshandiswa pakati pega yega chiteshi. Iyo luma inogona kunge iine resolution ye8 bits uye chrominance 4 kana 5 bits. Zvichienderana nemhando yemidziyo yauri kushandisa pane akati wandei mazinga aripo, anosanganisira:

• 4:4:4 uye 4:2:2 (4 bits pachiteshi chimwe nechimwe),
• 4:2:0 (4 bits for luma, 2 for blue and 2 for red).

Zvishandiso zveChrominance

Chrominance, kana ichishandiswa mukugadzira vhidhiyo, inoreva kushandiswa kwe penda muvhidhiyo. Chrominance chishandiso chakakosha pakugadzira zvinoratidzira uye zvakajeka zvinoonekwa, zvichibvumira vatungamiriri kuti vawedzere mafambiro uye manzwiro echiitiko.

Ichi chinyorwa chichaongorora nzira dzakasiyana siyana dzinogona kushandiswa chrominance mukugadzira vhidhiyo, kusanganisira kushandiswa kwe:

• Ruvara rwekuisa
• Color keying
• Mavara palettes

Ruvara Kuchengeta

Imwe yeanonyanya kukosha maapplication echrominance mukugadzira vhidhiyo ndeye ruvara grading. Colour grading inzira yekusimudzira mufananidzo wevhidhiyo. Sezvinoreva zita, rinoshandisa nzira dzakasiyana-siyana kugadzirisa hues, saturations uye humwe hunhu hwekuita kuti pfuti ibude pachena kana kusanganisa zvakaikomberedza. Chrominance levels zvinonyanya kukosha kune iyi nzira, sezvo inogona kushandiswa kugadzira imwe mamiriro kana toni.

Semuyenzaniso, kana chiitiko chikaiswa pamhenderekedzo yegungwa mambakwedza uye ichida kuve nekunzwa ethereal, mazinga echrominance anogona kugadziridzwa zvinoenderana nekuwedzera kudziya kwezuva uye nekuwedzera madiki matema eblue kuti anzwe mweya. Saizvozvo, kana chiitiko chichida mamwe manzwiro kana mutambo, iwo saturation mazinga anogona kuwedzerwa uchiri kuchengetedza kutendeseka kweiyo yekutanga mufananidzo mhando nekugadzirisa kuburikidza nechrominance control.

Kugadzika kwemavara kunobatsira kuona kuti mapfuti ese ari mukati mepurojekiti yakapihwa anooneka achienderana maererano nematoni uye anonzwa kuitira kuti kugadzirisa uye kugadzirwa kwemashure kuenderere mberi.

Video Compression

Vhidhiyo compression ndiyo maitiro ekubvisa ruzivo kubva pachiratidzo chevhidhiyo kuitira kuderedza saizi yefaira kana kutapurirana bandwidth. Izvi zvinosanganisira kudzikisira ruzivo uye/kana kugadziriswa kwechero vhidhiyo yakapihwa. Chrominance inonyanya kukosha pakuita uku sezvo ichisarudza zvinhu zvemavara mukati mechiratidzo chevhidhiyo.

Nekudzikisira chrominance, kudzvanywa kwevhidhiyo kunogona kuita budiriro yakakosha maererano nekuchengetedza data uye kufambisa kutapurirana, pasina mhedzisiro pamhando. Chrominance inogona kuiswa kune akawanda akasiyana marudzi enhau, akadai senhepfenyuro yeterevhizheni, mavhidhiyo ekutepfenyura uye Blu-ray discs.

Sezvo chrominance inotakura ruzivo rwakakosha rwekuona rwatinodaidza ruvara, kuikodha zvishoma asi zvinobudirira kunotitendera kudzvanya mavhidhiyo pasina kupa kurongeka kwemavara kana kuzara - zvinhu zviviri zvakakosha mukugadzira. zvinhu zvinooneka. Chrominance inokanganisa kuti yakawanda sei data inodiwa kuchengetedza uye/kana kufambisa zvinonzwika-zvinoonekwa zvemukati; nekuishandisa zvizere, tinoratidza kuramba tiri vashoma tichichengeta a yepamusoro yehutano mukuona kwedu.

Ratidza Kururamisa

Chiratidzo chechrominance ndiyo inotsanangura huwandu hweruvara mumufananidzo, pane kupenya. Mukugadzira vhidhiyo uye post-kugadzirisa, kuona yakabudirira chrominance chiyero kunosanganisira kushandisa software kugadzirisa iyo tembiricha yeruvara rwechifananidzo kana chifananidzo. Iyi inzira inozivikanwa se ruvara kururamisa.

Kugadziriswa kwemavara muvhidhiyo post-kugadzirwa kazhinji kunoreva chero shanduko yeiyo iripo mifananidzo senge kuwedzera kana kuderedza kuzara, kugadzirisa chiyero chechena, nekushandura mamwe maitiro ekusiyanisa. Aya magadzirirwo anogona kusandura chitarisiko chepikicha zvakanyanya nekushandura magadzirirwo akajeka uye akasviba zvikamu, kuti mavara akasanganiswa sei, kusimba kwemavara akasiyana pane zvinoonekwa, nezvimwe.

Muchidimbu, gadziriso kuchrominance inoshanda sechishandiso chekupa chero chiitiko inzwi uye manzwiro akafanotemerwa. Kugadziriswa kweruvara kunowanzoitika kana paine mavara asiri iwo kana asingawirirane pamufananidzo izvo zvinogona kukonzera kuvhiringika kana uchiedza kududzira zvazvinoreva kana chinangwa. Semuyenzaniso, kana kuvheneka paseti kusinganyatsoenderana kubva pachiitiko-ku-chinoitika saka izvi zvinogona kutungamira kune misiyano yemavara pakati pemapfuti maviri anotorwa maminetsi akasiyana kubva kune mumwe nemumwe. Nekugadzirisa chrominance iyi nyonganiso inogona kudzikiswa nekudzosa zvese mukuwirirana nazvo - kunyanya nezvemavara ayo - saka inoratidzika kunge yakavhenekerwa zvakanaka uye inopindirana neyakange yambofungidzirwa sechikamu chechinangwa chechidimbu.

mhedziso

Kupfupisa, chrominance inhengo yeruvara inogona kuchinjwa uye kushandiswa paunenge uchigadzira vhidhiyo. Chrominance, kana chroma muchidimbu, inotemwa nekuyera hue uye saturation reruvara kuti ripe chimiro chayo chakasiyana. Manipulating chrominance chishandiso chine simba kune vanogadzira mafirimu, sezvavanogona kuishandisa kugadzira surreal uye yakanaka mifananidzo neunyanzvi hwekuvhenekesa michina.

Nekunzwisisa izvo zvakakosha zvechrominance, vagadziri vemafirimu vanogona kuve nekutonga kwakawanda pamusoro pemamiriro ekunze emapurojekiti avo.

Mhoroi, ndini Kim, amai uye munhu anofarira zvekumira-famba ane ruzivo mukugadzira midhiya nekuvandudzwa kwewebhu. Ndine chido chikuru chekudhirowa uye mifananidzo, uye ikozvino ndiri kunyura nemusoro munyika yekumira-kufamba. Neblog rangu, ndiri kugovera zvandinodzidza nemi varume.