Читать книгу Multimedia Security, Volume 1 - William Puech - Страница 20

The first step of acquiring a raw image consists of counting the number of incident photons over the sensor along the exposure time. There are two different technologies used in camera sensors: charge coupled devices (CCDs) and complementary metal-oxide-semiconductors (CMOS). Although their operating principles differ, both can be modeled in a very similar way (Aguerrebere et al. 2013). Both sensors transform incoming light photons into electronic charge, which interacts with detection devices to produce electrons stored in a potential light well. When the latter is full, the pixels become saturated. The final step is to convert the analog voltage measurements into digital quantized values.