Image-Processing Algorithms
Kazuhiro Sato · 2017
This chapter describes image-processing algorithms used in digital still cameras from a theoretical point of view, as well as the many peripheral functions needed to work in a real camera, such as viewfinder, focus and exposure control, joint photographic expert group compression, and storage media. The lens focuses incident light on a charge-coupled device (CCD) sensor to form an image, which is converted to an analog signal. This signal is read out, digitized, and sent to the digital signal-processing block. The number of photons striking the sensor is linearly proportional to the incident light intensity. The number of electrons displaced, and thus the output signal, is proportional to the number of photons. It is best to digitize the input data value between black and maximum levels so as to utilize the dynamic range of a sensor fully. Most CCDs generate some noise signal like thermal noise even when no input light signal is present.