The Median Blur filter broadens colour regions in the image. At low settings it’s useful for removing noise, especially as it retains edges better than Gaussian Blur. At much higher intensities it introduces flat areas of colour.
This filter can be found in the Filters panel, in the Blurs category. It can also be applied as a non-destructive, live filter.
The following settings can be adjusted on the vertical slider:
The following settings can be adjusted on the context toolbar: