chhavi nirmaan

chhavi nirmaan kaa adhyayan radiometric aur jyaamitiya prakriyaon koo shamil kartaa haye jinake dwara 3 dee vastuon kii 2 dee chhaviyaan banati hain. digital chhaviyon key mamle mein, chhavi nirmaan prakriya mein analogue seey digital roopaantaran aur namunakaran bhee shamil haye.
imaging.
imaging prakriya ack chhavi tala key liye ack vastu kaa maanchitran haye. chhavi parr pratyek bindu vastu parr ack bindu seey mell khaata haye. ack prakaashit vastu ack lens kii or prakaash koo bikher degi aur lens chhavi banaane key liye prakaash koo ekatra karega aur kendrit karega. chhavi kii oonchaai aur vastu kii oonchaai kaa anupaat aavardhan haye. chhavi kii satah kii sthaanik seema aur lens kii kendra kii lambai lens key drishya kshetra koo nirdhaarit karati haye. darpan kii chhavi key gathan mein vakrata kaa kendra hotaa haye aur darpan kii isaki kendra lambai vakrata key kendra kaa aadhaa hotaa haye.
roshni.
ack vastu koo utsarjak srot jaise kii soorya, ack prakaash bulb yaa ack prakaash utsarjak diode seey prakaash seey prakaashit kiya jaa sakata haye. vastu parr prakaash ghatana vastu key satah gunon parr nirbhar tareeke seey paraavartit hoti haye. khurdari satahon key liye, paraavartit prakaash satah key dwi-dishaatmak paraavartan vitaran kaary (bee. aar. dee. aff.) dwara varnit tareeke seey bikhare hue haye. ack satah kaa bee. aar. dee. aff. prati varg meater prati steradian (vikiran) seey baahar nikalane kii shakti aur prati varg meater (vikiran) ghatana shakti kaa anupaat haye. bee. aar. dee. aff. aamtaur parr konn key saath bhinn hotaa haye aur tarang dairdhya key saath bhinn hoe sakata haye, lekin ack vishisht mahatvapurna mamla ack aisee satah haye jisamen sthir bee. aar. dee. aff. hotaa haye. iss satah key prakaar koo lambertian key roop mein sandarbhit kiya jaataa haye aur bee. aar. dee. aff. kaa parimaan r/π haye, jahan r satah kii paravartansheelta haye. lens kii or failane vaale bikhare hue prakaash kaa hissa drishya key kshetra mein imaging lens key pravesh putali dwara ekatra kiya jaataa haye.
drishya aur kalpana kaa kshetra.
lens key drishya kaa kshetra chhavi tala key aakar aur lens kii kendra lambai seey seemit haye. chhavi parr ack sthaan aur vastu parr ack sthaan key beach sambandh y = f * ٹین (θ) haye, jahan y chhavi tala kii adhikatam seema haye, f lens kii kendra lambai haye aur θ drishya kshetra haye. yadi y chhavi kaa adhikatam radial aakar haye tou θ lens key drishya kaa kshetra haye. jabaki ack lens dwara banaai gaee chhavi nirantar haye, ise asatat kshetra binduon key ack samooh key roop mein model kiya jaa sakata haye, pratyek vastu parr ack bindu kaa pratinidhitva kartaa haye. chhavi kii gunavatta lens mein vichalan aur seemit aperture stop dwara banaae gaye vivartan dwara seemit haye.
chhaatr aur rukte hain.
lens kaa aperture stop ack yaantrik aperture haye joe pratyek kshetra bindu key liye prakaash sangrah koo seemit kartaa haye. pravesh putali lens key object side parr optical tatvon dwara banaae gaye aperture stop kii chhavi haye. ack vastu dwara bikhare hue prakaash koo pravesh putali dwara ekatra kiya jaataa haye aur apavartak tatvon kii ack shrinkhala key madhyam seey chhavi tala parr kendrit kiya jaataa haye. chhavi tala parr kendrit prakaash kaa shanku pravesh putali key aakar aur lens kii kendra lambai dwara nirdhaarit kiya jaataa haye. ise aksar lens key aff-stop yaa aff-number key roop mein sandarbhit kiya jaataa haye. f/#= f/d jahan d pravesh putali kaa vyaas haye.
pixellation aur rung banaam monochrom.
vishisht digital imaging pranaliyon mein, ack samvedak chhavi tala parr rakhaa jaataa haye. prakaash samvedak parr kendrit hotaa haye aur nirantar chhavi pixellated hoti haye. samvedak mein pratyek pixel parr prakaash ghatana pixel key bheetar ekikrit kii jaayegi aur ack aanupaatik electronic sanket utpann kiya jaayega. pixel kaa koniya jyaamitiya sankalp ataan (pee/aff) dwara diyaa jaataa haye, jahan pee pixel kii pitch haye. ise pixel feeled off vyu bhee kahaa jaataa haye. samvedak monochrom yaa rung kaa hoe sakata haye. ack monochrom samvedak key mamle mein, pratyek pixel parr prakaash ghatana ekikrit hoti haye aur parinami chhavi chitra kii tarah ack grayscale hoti haye. rangeen chhaviyon key liye, ack rung chhavi banaane key liye aam taur parr pixel parr ack mozek rung filter rakhaa jaataa haye. ack udaaharan bayer filter haye. pratyek pixel parr sanket ghatana koo phir ack bitt stream mein digitise kiya jaataa haye.
chhavi kii gunavatta.
chhavi kii gunavatta jyaamitiya aur bhautik donon vastuon parr nirbhar karati haye. jyaamitiya roop seey, ack chhavi mein pixel kaa uchch ghanatva cumm avarodhit pixellation dega aur iss prakaar ack behtar jyaamitiya chhavi gunavatta dega. lens vichalan bhee chhavi kii gunavatta mein yogdan karate hain. bhautik roop seey, chhidra key rukane key kaaran vivartan f-sankhya key kaary key roop mein hull karane yogya sthaanik aavrittiyon koo seemit curr dega.
aavritti kshetra mein, modulan sthanantaran kaary (aim. tii. aff.) imaging pranali kii gunavatta kaa ack upaay haye. aim. tii. aff. chhavi tala parr vikiran mein ack signsoidal bhinnata kii drishyata kaa ack upaay haye joe signsoid kii aavritti key ack kaary key roop mein haye. isamen vivartan, vichalan aur pixellation key prabhaav shamil hain. lens key liye, aim. tii. aff. putali kaary kaa swa-sambandh haye, isaliye yeh seemit putali seema aur lens vichalan key liye jimmedaar haye. samvedak aim. tii. aff. pixel jyaamiti kaa forier parivartan haye. ack varg pixel key liye, mtf (φ) = sin (πxp)/πxp jahan p pixel kii chaudaai haye aur φ sthaanik aavritti haye. lens aur detector key sanyojan kaa aim. tii. aff. dou ghatak aim. tii. aff. aiss. kaa utpaad haye.
dhaarana.
rangeen chhaviyon koo dou tarikon seey dekhaa jaa sakata haye. computer drishti key mamle mein samvedak parr prakaash ghatana mein chhavi shamil hoti haye. drishya dhaarana key mamle mein, maanav aankh kii prakaash key liye ack rung nirbhar pratikriya hoti haye isaliye iska hisab rakhaa jaanaa chaahiye. grayscale mein parivartit karate samay yeh mahatvapurna vichaar haye.
aankh mein chhavi kaa nirmaan.
aankh key lens aur ack sadharan optical lens key beach mukhya antar yeh haye kii pahala lachila haye. lens kii poorvavarti satah kii vakrata kii trijya isaki pashchavarti satah kii trijya seey adhik hoti haye. lens kaa aakar pitt shareer key tantuon mein tanaav dwara niyantrit hotaa haye. door kii vastuon parr dhyaan kendrit karane key liye, niyantrit karane vaali maanspeshiyon key kaaran lens apekshaakrit chapata hoe jaataa haye. isi tarah, yeye maanspeshiyaan lens koo motee honey detee hain taaki aankh key paas kii vastuon parr dhyaan kendrit kiya jaa sakey.
lens key kendra aur retina (fokal lambai) key beach kii doori lagbhag 17 mimi seey lagbhag 14 mimi taka hoti haye, kyonki lens kii apavartak shakti apane nyuntam seey adhikatam taka badh jaati haye. jaba aankh lagbhag 3 meater seey adhik door kissy vastu parr dhyaan kendrit karati haye, tou lens apani sabse cumm apavartak shakti pradarshit kartaa haye. jaba aankh kissy karibi vastu parr dhyaan kendrit karati haye, tou lens sabse adhik prabal roop seey apavartak hotaa haye.

