The cameras and recording media available for modern digital image processing applications are changing at a significant pace. To dwell too long in this section on one major type of camera, such as the CCD camera, and to ignore developments in areas such as charge injection device (CID) cameras and CMOS cameras is to run the risk of obsolescence. Nevertheless, the techniques that are used to characterize the CCD camera remain "universal" and the presentation that follows is given in the context of modern CCD technology for purposes of illustration.