A Bayer filter is a color filter array used in digital image sensors to create a color image. It is composed of a mosaic of tiny red, green, and blue filters placed over the pixel sensors. Each pixel sensor captures only one color component of the light. The Bayer filter pattern has twice as many green filters as red or blue ones because the human eye is more sensitive to green light, which enhances perceived image sharpness. This color information is then interpolated to produce a full-color image through a process called demosaicing. The Bayer filter is crucial in digital photography because it allows cameras to capture color images using monochromatic sensors.