[ DSNU ] – Yintoni isignali emnyama engafaniyo (DSNU) ?

Isibonisi esiMnyama esingeyonto iUniformity (DSNU) ngumlinganiselo wenqanaba lenguqu ezimeleyo yexesha ngasemva kumfanekiso wekhamera. Inika inkcazo yamanani erhabaxa yomgangatho waloo mfanekiso ungasemva, ngokumalunga neepateni okanye izakhiwo ezinokuthi zibekho ngamanye amaxesha.

Kwimifanekiso yokukhanya okuphantsi, umgangatho ongasemva wekhamera unokuba yinto ebalulekileyo. Xa kungekho fotoni kwikhamera, imifanekiso efunyenweyo ayizukubonisa amaxabiso epixel ka-0 grey level (ADU). Ixabiso 'le-offset' lihlala likhona, elifana nemigangatho engwevu eyi-100, apho ikhamera iya kubonisa xa kungekho kukhanya, kunye okanye thabatha impembelelo yengxolo kumlinganiselo. Nangona kunjalo, ngaphandle kokulungelelaniswa ngononophelo kunye nokulungiswa, kusenokubakho ukwahluka ukusuka kwipikseli ukuya kwipikseli kweli xabiso limiselweyo. Olu lwahlulo lubizwa ngokuba 'yiNgxolo yePateni eFixiweyo'. I-DNSU imele ubungakanani bale ngxolo yepateni esisigxina. Imele ukutenxa okusemgangathweni kwexabiso le-pixel offset, elilinganiswa kwii-electron.

Kwiikhamera ezininzi zokukhanya okuphantsi, i-DSNU ihlala ingaphantsi kwe-0.5e-. Oku kuthetha ukuba usetyenziso oluphakathi okanye oluphezulu olunamakhulu okanye amawaka eefotoni ezithathiweyo ngepixel nganye, eli galelo lengxolo alinamsebenzi kwaphela. Ngokwenene, kwizicelo zokukhanya okuphantsi kwakhona, ukubonelela nge-DSNU isezantsi kunengxolo yokufunda yekhamera (ngokuqhelekileyo i-1-3e-), le ngxolo yepateni esisigxina ayinakwenzeka ukuba idlale indima kumgangatho womfanekiso.

Nangona kunjalo, i-DSNU ayisiyiyo umboniso ogqibeleleyo wengxolo yepateni esisigxina, njengoko isilela ukubamba izinto ezimbini ezibalulekileyo. Okokuqala, iikhamera ze-CMOS zinokubonisa iipateni ezicwangcisiweyo kolu tshintsho lwe-offset, rhoqo zikwimo yeekholamu zeepikseli ezahlukileyo enye kwenye ngexabiso labo lokulinganisa. Le ngxolo 'yePhatheni yeKholamu eZinzileyo' ibonakala kakhulu emehlweni ethu kunengxolo engamiselwanga, kodwa lo mahluko awumelwa lixabiso le-DSNU. Ezi zixhobo zobugcisa zikholamu zinokuvela ngasemva kwimifanekiso yokukhanya ephantsi kakhulu, njengaxa isignali efunyenweyo ingaphantsi kwe-100 yeefoto-electron. Ukujonga umfanekiso 'womkhethe', umfanekiso oveliswa yikhamera ngaphandle kokukhanya, uya kukuvumela ukuba ujonge ubukho besandi sepateni eyakhiweyo.

Okwesibini, kwezinye iimeko, ukwahluka okucwangcisiweyo kwi-offset kunokuxhomekeka kwixesha, ukuhluka ukusuka kwesinye isakhelo ukuya kwesinye. Njengoko i-DSNU ibonisa kuphela inguqu ezimeleyo yexesha, ezi azifakwanga. Ukujonga ulandelelwano lwemifanekiso enomkhethe kuya kukuvumela ukuba ujonge ubukho besandi sepateni exhomekeke kwixesha elicwangcisiweyo.

Njengoko kuphawuliwe, nangona kunjalo, i-DSNU kunye nokwahluka kwe-background offset akuyi kuba yinto ebalulekileyo kwi-medium-to-high-light-applications kunye namawaka eefotoni nge-pixel nganye, njengoko le miqondiso iya kuba namandla kakhulu kunokwahluka.