22/04/29Rashin daidaituwa na Hotuna (PRNU) wakilci ne na daidaituwar amsawar kyamara ga haske, mai mahimmanci a wasu aikace-aikacen haske mai haske.
Lokacin da kyamara ta gano haske, ana auna adadin na'urorin lantarki na hoto da kowane pixel ya ɗauka yayin fallasa, kuma a ba da rahoto ga kwamfuta azaman ƙimar launin toka na dijital (ADU). Wannan jujjuyawar daga electrons zuwa ADUs yana biye da wani ƙayyadaddun rabo na ADU akan kowane electron da ake kira riba mai canzawa, da ƙayyadaddun ƙimar biya (yawanci 100 ADU). Ana ƙayyade waɗannan ƙimar ta Mai canza Analogue-zuwa-dijital da Amplifier da aka yi amfani da su don juyawa. Kyamarorin CMOS suna samun saurin saurin su da ƙananan halayen surutu ta hanyar aiki a layi daya, tare da ɗaya ko fiye analog-zuwa-dijital masu juyawa kowane ginshiƙi na kyamara, da amplifier ɗaya akan pixel. Duk da haka, wannan yana gabatar da dama ga ƙananan bambance-bambancen samun riba da kashewa daga pixel zuwa pixel.
Bambance-bambance a cikin wannan ƙimar biya na iya haifar da ƙayyadaddun hayaniyar ƙirar ƙira a ƙaramin haske, wakilta taDSNU. PRNU tana wakiltar kowane bambance-bambancen samun riba, rabon electrons da aka gano zuwa nunin ADU. Yana wakiltar daidaitaccen karkatar da ƙimar ribar pixels. Ganin cewa bambance-bambancen da aka haifar a cikin ƙimar ƙima zai dogara da girman sigina, ana wakilta shi azaman kashi.
Mahimman ƙimar PRNU sune <1%. Ga duk ƙananan ƙananan haske da matsakaicin haske, tare da sigina na 1000e- ko žasa, wannan bambance-bambancen zai zama maras muhimmanci idan aka kwatanta da karanta sauti da sauran hanyoyin amo.
Har ila yau, lokacin da ake yin hotunan matakan haske mai girma, ba zai yiwu ba bambancin ya zama mahimmanci idan aka kwatanta da sauran hanyoyin amo a cikin hoton, kamar amo harbin photon. Amma A cikin aikace-aikacen hoto mai haske waɗanda ke buƙatar madaidaicin ma'auni, musamman waɗanda ke amfani da matsakaicin matsakaici ko firam-summing, ƙananan PRNU na iya zama da fa'ida.
