Content deleted Content added
Changed "Bayer sensors" (which is just one type of filter pattern) to "Integral color sensors", which is the correct term, and provided an improved, properly referenced description. |
Added URL for reference 15 and made minor changes to Bayer Pattern description |
||
Line 35:
[[File:Absorption-X3.svg|right|thumb|200px|Foveon's scheme of vertical filtering for color sensing]]
There are several main types of color image sensors, differing by the type of color-separation mechanism:
* '''Integral color sensors'''<ref>{{Cite journal |last=Dillon |first=Peter |date=Dec 1976 |title=Integral color filter arrays for solid-state imagers |url=https://ieeexplore.ieee.org/document/1478779 |journal=Technical Digest International Electron Device Meeting (IEDM), Washington, DC, Dec 1976 |pages=400-403 |via=IEEE}}</ref> use a [[color filter array]] fabricated on top of a single monochrome CCD or CMOS image sensor. The most common color filter array pattern, the [[Bayer pattern]], uses a checkerboard arrangement of two green pixels for each red and blue pixel, although many other color filter patterns have been developed, including patterns using cyan, magenta, yellow, and white pixels<ref>{{Cite web |last=Parulski |first=Kenneth |date=August 1985 |title=Color Filters and Processing Alternatives for One-chip Cameras |url=https://ieeexplore.ieee.org/document/1484879}}</ref>. Integral color sensors were initially manufactured by transferring colored dyes through photoresist windows onto a polymer receiving layer coated on top of a monochrome CCD sensor.<ref>{{Cite web |last=Dillon |first=Peter |date=February 1978 |title=Fabrication and performance of color filter arrays for solid-state imagers |url=https://ieeexplore.ieee.org/document/1479439}}</ref> Since each pixel provides only a single color (such as green), the "missing" color values (such as red and blue) for the pixel are interpolated using neighboring pixels.<ref>{{Cite web |last=Dillon |first=Peter |date=February 1978 |title=Color imaging system using a single CCD area array |url=https://ieeexplore.ieee.org/document/1479440}}</ref> This processing is also referred to as [[demosaicing]] or de-bayering.
* '''[[Foveon X3 sensor]]''', using an array of layered pixel sensors, separating light via the inherent wavelength-dependent absorption property of silicon, such that every ___location senses all three color channels. This method is similar to how color film for photography works.
* '''[[Three-CCD camera|3CCD]]''', using three discrete image sensors, with the color separation done by a [[dichroic prism]]. The dichroic elements provide a sharper color separation, thus improving color quality. Because each sensor is equally sensitive within its [[passband]], and at full resolution, 3-CCD sensors produce better color quality and better low light performance. 3-CCD sensors produce a full [[Chroma subsampling|4:4:4]] signal, which is preferred in [[television broadcasting]], [[video editing]] and [[chroma key]] visual effects.
| |||