Chroma Keying and Working with Green Screens > Creating and Refining a Key in the Master Keyer >

# Removing Grain

After you have set your blend parameters for the front and back clips, you may want to remove grain from your clips. Graininess can make it difficult to pull a clean and effective key. Use the Degrain tools in the Master Keyer to remove grain from clips.

NoteDegrain parameters are animatable. Degrain samples are also animatable and appear in the Channel Editor as the Degrain_Matrix channel, located in the Key_Degrain folder. See Animating Keyframes.

To remove grain:

1. In the Master Keyer menu, select Degrain from the Sampling box.
2. Set the view to Result view.
3. Sample a grainy area of the image. To sample a single pixel, click the image. To sample an area of the image, Command-drag a selection box.

   The Degrain button is enabled and the algorithm is applied to the image—grain is removed from the image.

   NoteThe Degrain button is either enabled or disabled for the entire clip—you cannot turn it on and off for different frames in the clip.
4. Drag in the Degrain fields to modify the grain size and restore edge sharpness.

   (a) Size field(b) Edges field

   Drag: | To:
   --- | ---
   Size | Estimate the size of the grain in the image.
   Edges | De-sharpen the edge of the image. By default, Degrain sharpens the edges. Use the Edges field to restore the natural look of the edges in the image.

5. If you are not satisfied with the result, you can start over with a new sample, and then adjust the Degrain fields. To resample an area of the image, Command+Option-drag the image.

   The sample is outlined in green, indicating that you are resampling the image.

   NoteYou can also reset Degrain parameters. To reset Degrain parameters, click the Reset button, next to the sampling box.
6. If resampling the image and adjusting the Degrain fields does not sufficiently remove grain, enable More to increase the overall effect of Degrain.
   NoteThe More button is either enabled or disabled for the entire clip—you cannot turn it on and off for different frames in the clip. When you enable More, processing speed slows down.

After you have removed grain from your clips, you may still have to remove unwanted greys.

#### Related Information

- Creating and Refining a Key in the Master Keyer
- Chroma Keying and Working with Green Screens