Grayscale images do not have enough information to handle some inspection tasks like identification, sorting, and process control. In other cases, a solution is possible with the grayscale image, but is greatly simplified by taking into account color information. Below are some examples of inspection and sorting tasks that are facilitated by the use of color analysis:
A continuous acquisition streamed to disk would fill up a 6 GB hard drive in a matter of minutes!
A prism is commonly used in color cameras to split the light into its component wavelengths. The plot below shows a typical color line profile split into its red, green, and blue components.
The natural color space used by display monitors matches the way the human eye perceives colors. Cones in the retina of the human eye contain three pigments, each sensitive to either red, green, or blue light. Each color, though, can have a range of appearances based on its richness (saturation). In the figure below, each box contains only one "color" (hue), but illustrates a range of saturation values:
In the RGB representation, adding white light to the image will change all three of the components. A representation based on hue, however, is independent of lighting conditions--a red object has a red hue whether it is dimly or brightly lit.