Problematika senzorjev v digitalnih fotoaparatih

Osećanski Despić, Ivana (author), Boh Podgornik, Bojana (mentor)

Diplomsko delo se ukvarja s problematiko analognih senzorjev, ki so integrirani v digitalne fotoaparate. Teoretični del najprej predstavi, kaj je svetloba, nato arhitekturo CCD- in CMOS-senzorjev in glavno razliko med obema tipoma. Poglavje o problematiki digitalnih fotoaparatov predstavi najbolj pogoste dejavnike, ki vplivajo na kakovost fotografije. Prične se z opisom digitalnega šuma, njegovega videza in izvora. Sledi barvni artefakt, t. i. vijolični robovi, ki so pogosti na kontrastnih delih fotografije in uporabnikom bolj znani pod nazivom kromatična aberacija. Ker kromatična aberacija ni edini vzrok tega artefakta, sta omenjena še druga dva dejavnika, ki vplivata nanj, in sicer cvetenje pikslov ter demozaiciranje. Na kakovost barvne fotografije vplivata še barvna kvantizacija, ki določa število bitov, s katerim bo predstavljen piksel, in napačno ravnotežje beline, ki je posledica temperature barve svetlobnega vira. Zaključek poglavja o problematiki senzorjev v digitalnih fotoaparatih opisuje pojav zakasnitve zaklopa, ki je problem predvsem pri digitalnih aparatih cenejšega razreda. Za eksperimentalni del sta uporabljena dva digitalna fotoaparata z istim letnikom izdelave: Canon EOS 30D, ki ima CMOS-senzor, in Nikon Coolpix P3 s CCD-senzorjem. Za naknadno obdelavo fotografij sta bila izbrana plačniška programa Adobe Lightroom in Adobe Photoshop. Na osnovi rezultatov raziskave lahko zaključimo, da imajo fotografije, zajete s kompaktnim aparatom, več možnosti za pojav težav, opisanih pri problematiki digitalne fotografije, kot fotografije, zajete z zrcalnorefleksnim aparatom. Uporabnikom predlagamo učenje programov za naknadno obdelavo fotografij, saj omogočajo razvijanje kreativnosti in so odločilnega pomena pri popravljanju artefaktov.

• Language: Slovenian
• Keywords: digitalna fotografija, CMOS, CCD, problematika, Adobe Lightroom, Adobe Photoshop.
• Work type: Bachelor thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2018
• PID: 20.500.12556/RUL-101531
• Publication date in RUL: 14.06.2018

Secondary language

• Language: English
• Title: Sensor issues in digital cameras

Abstract

This thesis deals with issues of analog sensors, which are integrated into digital cameras. The theoretical part introduces what light really is, the architecture of CCD and CMOS sensors and main difference between them. The chapter about issues in digital cameras presents most common factors which can affect the quality of an image. It begins with the description of digital noise, its appearance and its origin. Next is the color artifact purple fringing which is commonly known as chromatic aberration. Since chromatic aberration itself is not the only cause of this artifact, I have mentioned other two factors that contribute to this problem: blooming and demosaicking. The quality of color photography is also influenced by color quantization, which determines the number of bits to represent a pixel and wrong white balance (due to different color temperatures of light sources). The chapter ends with describing the occurrence of shutter lag which is common in cheaper devices. For the experimental part, two digital cameras have been used: Canon EOS 30 with a CMOS sensor and Nikon Coolpix P3 with a CCD sensor. Adobe Lightroom and Adobe Photoshop were selected as post processing equipment. Based on the results we can conclude that images taken with a compact camera are more prone to the described issues of digital photography than DSLRs. We propose to users to learn more about post processing programs as they develop creativity and are of crucial importance for the correction of artifacts.

• Keywords: digital photography, CCD, CMOS, issues, Adobe Lightroom, Adobe Photoshop.