A Gaussian filter is a type of image processing technique used to reduce noise and detail in images. It works by applying a mathematical function, known as the Gaussian function, which creates a bell-shaped curve. This curve helps to smooth out variations in pixel values, making the image appear softer and less cluttered. The filter operates by averaging the pixels in a neighborhood around each pixel, weighted by their distance from the center pixel. This means that closer pixels have a greater influence on the final value than those further away. Gaussian filters are widely used in various applications, including computer vision and image editing.