Difference between revisions of "Bayer filter"
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| − | The light-sensitive silicon material in a digital [[sensor]] responds to all wavelengths (colors) of visible light. In order to represent the color of a scene being photographed, some method of separating the red, blue, and green primaries must be introduced, to achieve natural [[colour reproduction|color reproduction]]. The method almost universally used (as of 2012) is to place a mosaic of tiny color filters over individual pixels, typically in the 2×2 grid pattern developed by [[Kodak]] engineer Bruce Bayer and patented 1976<REF>[http://www.google.com/patents/US3971065?printsec=abstract#v=onepage&q&f=false US Patent 3,971,065] "Color Imaging Array," at [http://www.google.com/patents Google patents].</REF> In this arrangement, there are twice as many green-filtered pixels as red- or blue-filtered ones, corresponding to the greater sensitivity of the human eye to yellow-green light. After the brightness values of the individual, filtered pixels are read out, a software [[demosaicing]] process interpolates R, G, and B values for all the pixels in the sensor. | + | The light-sensitive silicon material in a digital [[sensor]] responds to all wavelengths (colors) of visible light. In order to represent the color of a scene being photographed, some method of separating the red, blue, and green primaries must be introduced, to achieve natural [[colour reproduction|color reproduction]]. The method almost universally used (as of 2012) is to place a mosaic of tiny color filters over individual pixels, typically in the 2×2 grid pattern developed by [[Kodak]] engineer Bruce Bayer and patented in 1976<REF>[http://www.google.com/patents/US3971065?printsec=abstract#v=onepage&q&f=false US Patent 3,971,065] "Color Imaging Array," at [http://www.google.com/patents Google patents].</REF>. In this arrangement, there are twice as many green-filtered pixels as red- or blue-filtered ones, corresponding to the greater sensitivity of the human eye to yellow-green light. After the brightness values of the individual, filtered pixels are read out, a software [[demosaicing]] process interpolates R, G, and B values for all the pixels in the sensor. |
Alternate '''color filter array''' arrangements are possible, and have been used, e.g. by [[Fuji|Fujifilm]]; in fact Kodak itself developed sensors with some unfiltered ("clear") pixels in the array, to permit greater overall sensitivity. [[Foveon]] sensors use a different technology, able to discriminate separate RGB values at each pixel location. | Alternate '''color filter array''' arrangements are possible, and have been used, e.g. by [[Fuji|Fujifilm]]; in fact Kodak itself developed sensors with some unfiltered ("clear") pixels in the array, to permit greater overall sensitivity. [[Foveon]] sensors use a different technology, able to discriminate separate RGB values at each pixel location. | ||
Revision as of 19:41, 2 March 2012
The light-sensitive silicon material in a digital sensor responds to all wavelengths (colors) of visible light. In order to represent the color of a scene being photographed, some method of separating the red, blue, and green primaries must be introduced, to achieve natural color reproduction. The method almost universally used (as of 2012) is to place a mosaic of tiny color filters over individual pixels, typically in the 2×2 grid pattern developed by Kodak engineer Bruce Bayer and patented in 1976[1]. In this arrangement, there are twice as many green-filtered pixels as red- or blue-filtered ones, corresponding to the greater sensitivity of the human eye to yellow-green light. After the brightness values of the individual, filtered pixels are read out, a software demosaicing process interpolates R, G, and B values for all the pixels in the sensor.
Alternate color filter array arrangements are possible, and have been used, e.g. by Fujifilm; in fact Kodak itself developed sensors with some unfiltered ("clear") pixels in the array, to permit greater overall sensitivity. Foveon sensors use a different technology, able to discriminate separate RGB values at each pixel location.
Notes
- ↑ US Patent 3,971,065 "Color Imaging Array," at Google patents.
