Bayer filter mosaic is a color filter array (CFA) for arranging RGB color filters on a square grid of photo sensors. Its particular arrangement of color filters is used in most single-chip digital image sensors with CMOS technology used in digital cameras, camcorders, and scanners to create a color image. The filter pattern is 50% green, 25% red and 25% blue, hence is also called RGB or other permutation such as RGB.
It is named after its inventor, Dr. Bryce E. Bayer of Eastman Kodak. Bryce Bayer’s patent called the green photo sensors luminance-sensitive elements and the red and blue ones chrominance-sensitive elements. He used twice as many green elements as red or blue to mimic the human eye’s greater resolving power with the green light. The elements are referred to as sensor elements, pixel sensors, or simple pixels; sample values detected by them, after interpolation, become image pixels.
The raw output of Bayer-filter cameras is referred to as a Bayer pattern image. Since each pixel is filtered to record only one of three colors, the data from each pixel cannot fully determine color on its own. To obtain a full-color image, various demosaicing algorithms can be used to interpolate a set of complete red, green and blue values for each pixel.
Generally with a Bayer pattern sensor, actual resolution will be somewhere between the "native" value and half this figure, with different demosaicing algorithms producing different results. Additionally, most digital cameras (both Bayer and three-chip designs) employ optical low-pass filters to avoid aliasing. Such filters also reduce resolution.
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