The idea of a CCD is simple. We can imagine it as a memory chip without a "top". Photons encountering the memory cells create electrons in these cells (photoelectric effect) thereby the number of photons is proportional to the number of electrons. The photon's wavelength, however, is not 'transferred' to the electrons. Hence CCD chips are color blind.
Therefore, during the last step of the production of a color CCD every pixel EITHER obtains a red OR a green OR a blue 'coating'. Nowadays the distribution of these red, green and blue color spots is mainly based on the ideas of Mr. Bayer and thus the widely used tecnical term 'Bayer filter'.
We usually expect that a 'normal' color camera outputs pixels consisting of a red value AND a green value AND a blue value although the CCD actually only provides us with one of these values. The two missing values are 'estimated' by the camera electronics using a so-called color space interpolation algorithm.
In the context of measurement applications it is obviously not recommendable to work with interpolated data. Therefore, more and more so-called 'Bayer cameras' are used for such applications. They provide the CCD's 'raw content' and hence a monochrome image with 8 bit/pixel at first glance.
Actually we have three additional bits for every pixel indicating WHETHER it is a red OR a green OR a blue However, we are not forced to have this information 'in tow' since it is determined by the pixel's coordinate.
Learn More About Bayer Cameras
- Download Bayer Demonstrator
Software that educates about Bayer cameras; what they are; how they work etc.
- Download 'How Color Cameras Work' Whitepaper
Technical whitepaper that describes how Bayer cameras work.
The Imaging Source Bayer Cameras
The Imaging Source manufactures the following kinds of Bayer camera: