A Bayer color image is a type of color image that uses the Bayer filter array pattern to capture color information. It is a widely used method in digital image sensors.


In a Bayer color image sensor, individual pixels are sensitive to only one color channel: red, green, or blue. The sensor arranges these pixels in a specific pattern known as the Bayer pattern, which typically consists of alternating rows of green and red pixels, with the remaining rows containing blue and green pixels.


The Bayer filter array allows the image sensor to capture color information by interpolating the missing color channels for each pixel. This interpolation process, known as demosaicing, estimates the missing color values based on the known color values of neighboring pixels.


Phoranso automatically recognizes Bayer color FITS files by the presence of the FITS keyword BAYERPAT. It converts Bayer color images to full-color images using a technique known as demosaicing. Once completed, the full-color image is converted to a greyscale image, ready for photometric processing.

Example of a Bayer color image showing the typical Bayer pattern:



Same image after demosaicing and conversion to greyscale: