You can combine up to five matrix or procedural filter elements into a custom filter. Procedural filters use a predefined procedure instead of matrix calculations to alter the image.

To customize a filter using a procedural filter:

1. Select the filter element: Filter 1, Filter 2, Filter 3, Filter 4, or Filter 5.
2. Select Procedural from the Filter Type box.

   The Procedural Filter menu appears.

   
   

3. Select the procedural filter you want to use.

   Enable:	To:
   Invert	Invert the image.
   Rect	Blur the image. Use the Height and Width fields that appear to adjust the direction and intensity of the blur.
   Sobel	Use an edge-detection filter. Select the direction in which the filter is applied from the field that appears in the menu. The options are Diagonal Right, Diagonal Left, and Horizontal/Vertical.
   Prewitt	Use an edge-detection filter. As with the Sobel filter, you can select the direction in which the filter is applied.

4. Click Enable to select the filter element.
5. To bypass the chrominance (hue and saturation) channels or the luminance (brightness) channel of an image, enable Bypass Chroma or Bypass Luminance.
6. Repeat these steps for each element you want to include in the custom filter.
7. Select Result view to preview the effect of the new filter on the source clip. You can continue to adjust the filter elements as required.
8. Save the new filter in the filter library. See Saving Custom Filters.
9. To apply the new filter to the clip, click Process in the Filter menu.

   The original image

   After applying the Sobel procedural filter