nr Noise Reduction Sharpen Bound

Reduces the noise in the image. Valid values are in the range -100 to 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.

The 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.