nr Noise Reduction Sharpen Bound
Reduces the noise in the image. Valid values are in the range
100. If no value is supplied,
nrs will be set to the default value of
20. If only
nrs is set, then
nr will be set to its default value.
nr value sets the threshold at which noise is removed. Pixels that fall below this threshold will be blurred. Pixels above the threshold will be sharpened according to the
nrs parameter value. If neither value is supplied, then no noise reduction will be applied.