The basic job of CCD (charge coupled device) and CMOS (complementary metal oxide semiconductor) sensors is to convert light (photons) into electronic signals (electrons). The main difference between the two sensor types is the technical design of the sensor itself.

CCD sensors have been available for more than 25 years and they have been very successful in the industrial and consumer markets. A variety of technical advantages have made CCD sensors the preferred choice in the industrial marketplace for quite some time. But many recent improvements in CMOS technology have been a great benefit to CMOS sensor performance.

In general, the low noise level, high fill factor, and good signal-to-noise ratio exhibited by CCD sensors result in very high quality images. These characteristics make cameras based on CCD sensors a good fit for machine vision applications. CMOS sensors have made a path into machine vision based largely on their advantage in speed (frame rate) and resolution (number of pixels) compared to CCD imagers. Improvements in CMOS technology and demand from high volume users such as the automotive market are making CMOS image sensors more and more attractive for machine vision applications. When some basic corrections are made to the images from CMOS sensors, an image quality equivalent to CCD sensors can be achieved.