Median Blur

This transformation applies a median filter to the input image. Each pixel in the input image is replaced by the median of its neighbors. A 3x3 or 5x5 median filter is useful for reducing image noise – especially isolated light or dark pixels that stand out against the background.

Amount

The amount control lets you control how much of the median blur transformation is applied to the input image. You can apply a percentage of the transformation to the entire image, or you can specify an amount mask to restrict the effects of the transformation to only part of the input image.

Method

This control lets you choose the size of the neighborhood used by the median filter.

3 X 3 -- replaces each pixel with the median of a 3x3 neighborhood.

5 X 5 -- replaces each pixel with the median of a 5x5 neighborhood.

Variable -- lets you select larger radius sizes and performs a fast approximation to the true median. When Variable is selected, the Radius slider is displayed. Variable only works for 8-bit black and white or 24-bit color images -- if the input image is 16-bit black and white or 48-bit color, it is first converted internally to 8-bit black and white or 24-bit color before applying the median filter.

Radius

This slider is displayed when Method is set to Variable. The larger the radius value you select, the more the image is blurred. Whenever Variable is selected, the output image is always 8 bits/channel, even if the input image is 16 bits/channel.