what is a ccd :: machines that see

It is remarkable that machines that “see” are everywhere. Most obvious, of course, are the digital still picture and video cameras that record our fondest moments and play them back instantly. Things we think about less include: the scanners that check us out of grocery stores, the bank machines that read the special characters at the bottom of each check so our accounts are updated properly (and the check ends up back at our banks), the sensors that automatically turn lights on and off during the day, cameras for controlling a robot’s motion.

We are making a distinction between these machines and machines that only “record” things that it sees, like traditional film cameras. While they are similar in many ways, a key distinguishing characteristic is whether, after “seeing” something, a machine can act on it or cause something else to happen. In today’s technology, that means converting an image into some electrical representation that can be used inside a computer or some other set of electronics.