Image Capture and Processing
Charles S. Johnson · 2017
In order to understand what photons do in film photography, it is necessary to look at the photochemistry and photophysics at the atomic level. Sensors have all but replaced film for image capture, but this is just the tip of a mountain of advances in science and technology. Sensors and their use would be impossible without the microelectronics industry and the plethora of new products, especially microprocessors and memory chips. This chapter focuses on the way sensors work and their relative advantages, at least at this stage of their development. In both CCD and CMOS sensors the pixel array can be thought of as an array of small buckets designed to catch photons. The use of randomly distributed pixels in an image sensor appears to be an impractical solution because of problems with pixel readout and image processing. The human brain requires years to learn how to process the visual signals from randomly distributed cones and rods in the retina.