You use the Noise Reduction Quick Brush adjustment to remove digital noise in the area of the image the adjustment is brushed on.

Select an image.
Do one of the following:
In the Adjustments inspector or the Adjustments pane of the Inspector HUD, choose Quick Brushes > Noise Reduction from the Adjustments pop-up menu.
In the tool strip, choose Noise Reduction from the Quick Brush pop-up menu (with a brush icon).
The Noise Reduction Brush HUD appears, and the Noise Reduction adjustment controls appear in the Adjustments inspector and the Adjustments pane of the Inspector HUD, if both are shown.
Specify the brush stroke settings using the controls in the Noise Reduction Brush HUD.
For more information about the controls in the Brush HUD, see Controls in the Brush HUD. For more information about applying brush strokes to an image, see Working with Brushes.
Brush the adjustment on the area of the image where you want to reduce the digital noise.
The digital noise is removed from the area of the image where the Noise Reduction Quick Brush adjustment is applied.
Select an image with the Noise Reduction adjustment applied to it.
In the Noise Reduction area of the Adjustments inspector or the Adjustments pane of the Inspector HUD, modify the Noise Reduction adjustment by specifying the following settings:
Specify the area over which the Noise Reduction adjustment is applied using the Radius slider and value slider.
Specify the amount of edge detail you want to preserve in areas of high contrast using the Edge Detail slider and value slider.

The previously applied Noise Reduction adjustment is modified.