Editing Digital camera (section)

=== Filter mosaics, interpolation, and aliasing ===
[[File:Bayer pattern on sensor.svg|thumb|left|The Bayer arrangement of color filters on the pixel array of an image sensor.]]
Most current {{Clarify timeframe|date=February 2020}} consumer digital cameras use a Bayer filter mosaic in combination with an optical [[anti-aliasing filter]] to reduce the aliasing due to the reduced sampling of the different primary-color images.
A demosaicing algorithm is used to [[interpolation|interpolate]] color information to create a full array of RGB image data.

Cameras that use a beam-splitter single-shot [[3CCD]] approach, three-filter multi-shot approach, color co-site sampling or [[Foveon X3 sensor]] do not use anti-aliasing filters, nor demosaicing.


[[Firmware]] in the camera, or a software in a raw converter program such as [[Adobe DNG Converter|Adobe Camera Raw]], interprets the raw data from the sensor to obtain a full-color image, because the [[RGB color model]] requires three intensity values for each pixel: one each for the red, green, and blue (other color models, when used, also require three or more values per pixel).
A single sensor element cannot simultaneously record these three intensities, so a color filter array (CFA) must be used to selectively filter a particular color for each pixel.

The Bayer filter pattern is a repeating 2x2 [[mosaic]] pattern of light filters, with green ones at opposite corners and red and blue in the other two positions. The high proportion of green takes advantage of the properties of the human visual system, which determines brightness mostly from green and is far more sensitive to brightness than to hue or saturation. Sometimes a 4-color filter pattern is used, often involving two different hues of green. This provides potentially more accurate color, but requires a slightly more complicated interpolation process.<ref>{{Cite journal |last1=Cheremkhin |first1=P A |last2=Lesnichii |first2=V V |last3=Petrov |first3=N V |date=2014-09-17 |title=Use of spectral characteristics of DSLR cameras with Bayer filter sensors |journal=Journal of Physics: Conference Series |volume=536 |issue=1 |page=012021 |doi=10.1088/1742-6596/536/1/012021 |bibcode=2014JPhCS.536a2021C |s2cid=31560384 |issn=1742-6588|doi-access=free }}</ref>

The color intensity values not captured for each pixel can be [[interpolate]]d from the values of adjacent pixels which represent the color being calculated.<ref>{{Cite book|last=Malvar|first=Henrique|title=High Quality Linear Interpolation for Demosaicing of Bayer-Patterned Color Images|year=2004}}</ref>