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 for the sensor to include a mosaic of tiny color filters over individual pixels, typically in the 2×2 grid pattern developed by [[Kodak]] engineer ''' | + | 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 for the sensor to include a mosaic of tiny color filters over individual pixels, typically in the 2×2 grid pattern developed by [[Kodak]] engineer '''Bryce 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 recorded, 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. | ||
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| + | Bryce Bayer died 13 November 2012, having retired from Kodak in the 1990s<REF>[http://www.imaging-resource.com/news/2012/11/20/bryce-bayer-who-created-bayer-filter-for-digital-cameras-has-died Bryce Bayer obituary] from [http://www.imaging-resource.com Imaging Resource].</REF>. | ||
==Notes== | ==Notes== | ||
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==Links== | ==Links== | ||
*[http://en.wikipedia.org/wiki/File:Bayer_pattern_on_sensor.svg Diagram illustrating Bayer pattern] at [http://en.wikipedia.org/wiki/Main_Page Wikipedia] | *[http://en.wikipedia.org/wiki/File:Bayer_pattern_on_sensor.svg Diagram illustrating Bayer pattern] at [http://en.wikipedia.org/wiki/Main_Page Wikipedia] | ||
| + | *[http://image-sensors-world.blogspot.com/2012/11/bruce-bayer-died.html Bryce Bayer obituary] at [http://image-sensors-world.blogspot.com Image Sensors World], featuring original Kodak lab notebook page proposing a RGBG sensor filter array. | ||
[[Category:Glossary]] [[Category:Camera parts]] | [[Category:Glossary]] [[Category:Camera parts]] | ||
Revision as of 03:25, 22 November 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 for the sensor to include a mosaic of tiny color filters over individual pixels, typically in the 2×2 grid pattern developed by Kodak engineer Bryce 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 recorded, 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.
Bryce Bayer died 13 November 2012, having retired from Kodak in the 1990s[2].
Notes
- ↑ US Patent 3,971,065 "Color Imaging Array," at Google patents.
- ↑ Bryce Bayer obituary from Imaging Resource.
Links
- Diagram illustrating Bayer pattern at Wikipedia
- Bryce Bayer obituary at Image Sensors World, featuring original Kodak lab notebook page proposing a RGBG sensor filter array.
