BayerFilter

A Bayer filter is a color filter array (CFA) placed on the image sensor of most digital cameras to capture color information with a single sensor. It was developed by Bryce E. Bayer at Eastman Kodak in 1976 and became the standard approach for digital color imaging. The filter mosaic sits directly on top of the sensor’s photosites and determines which color light is recorded at each pixel location.

The standard Bayer pattern is called RGGB. In a 2x2 block, there is one red, one blue, and two green filters. The green filters outnumber the others because the human visual system is more sensitive to green light, and because luminance information (detail) is more strongly carried by green pixels. Each sensor pixel therefore records only one color component, and the missing colors are recovered later through a process called demosaicing, which interpolates the full RGB values from neighboring samples.

In practice, the raw data from a Bayer-filtered sensor undergoes processing to reconstruct a complete color image. Demosaicing algorithms vary in complexity, from simple interpolation to advanced edge-aware and noise-reduction methods. The green channel often drives luminance, while red and blue provide chrominance information. The approach enables high spatial resolution at a relatively low cost but can introduce color artifacts and require careful processing to achieve accurate color and detail.

While Bayer RGGB remains the dominant CFA in consumer devices, variations and alternative patterns exist (such as RGBW or CYGM), though they are far less common. The Bayer filter’s widespread use underpins the vast majority of modern digital photography and video capture.