Creative Effects > Image Filters > Customizing Filters >

# Using Matrix Filter Elements

A matrix specifies the relative influence of each pixel's colour value in the filter calculation. Each matrix consists of a grid of fields. The field at the centre of the grid represents the pixel currently being evaluated (the current pixel). The remaining fields represent the pixels surrounding the current pixel. The value you set in each field determines the relative influence of the corresponding pixel in the filter calculations. A pixel with a higher value is more influential in the calculations than a pixel with a lower value.

(a) Filter Type(b) Symmetry Type(c) Matrix

To customize a filter using matrix elements:

1. Select the current filter element: Filter 1, Filter 2, Filter 3, Filter 4, or Filter 5.

   You can use up to five filter elements in a single custom filter.

2. Select Matrix from the Filter Type box and select the matrix dimensions.

   The 3 x 3 button opens a matrix of three rows by three columns; the 5 x 5 button opens a matrix of five rows by five columns, and so on.

3. Enable Use Filter to activate the filter element.
4. Enter a numeric value in the matrix fields for all the pixels you want to consider. For information on balancing the matrix, see Balancing the Matrix.

   The matrix fields are numeric. Permissible values range from -255 to +255 in 8-bit mode, and from -4095 to +4095 in 12-bit mode.

   NoteClick Reset Matrix to reset all the values in the matrix.
5. To bypass the chrominance (hue and saturation) channels or the luminance (brightness) channel of an image, enable Bypass Chroma or Bypass Luminance.
6. If required, set the Symmetry options. See Using Symmetry Options.
7. Enable Automatic to preserve the average luminance of the clip. To boost or reduce the colours in the image, adjust the value in the Gain field. Values less than 100% subdue the colours and values greater than 100% boost the colours.
8. Repeat these steps for each element you want to include in the custom filter.
9. 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.
10. Save the new filter in the filter library. See Saving Custom Filters.
11. To apply the new filter to the clip, click Process.

Balancing the Matrix

You can create a balanced matrix to create various custom effects. Enable Balanced and then enter a value in a matrix field. An algorithm divides the number you entered by the total number of fields and then subtracts the result from each value in the matrix.

NoteGenerally, using this option also prevents colours in the clip from becoming too bright or too dark.

Using Symmetry Options

When changing values in the matrix, you can use the Symmetry options to change multiple elements in various symmetrical arrangements to produce different effects.

To use symmetry:

1. Set up a matrix filter element using the procedure in the previous section.
2. Select an option from the Symmetry Type box.

   Select: | To:
   --- | ---
   None | Change each element in the matrix individually without using the symmetry principle.
   Horizontal | Change two horizontally symmetrical elements.
   Vertical | Change two vertically symmetrical elements.
   Diagonal Positive | Change two diagonally symmetrical elements in the positive direction (lower left to upper right).
   Diagonal Negative | Change two diagonally symmetrical elements in the negative direction (lower right to upper left).
   All | Change four horizontally and vertically symmetrical elements.

3. Select the value shifting method.

   Enable: | To:
   --- | ---
   Same | Change all symmetrical elements to the same value.
   Invert | Change the symmetrical element by the same amount but in the opposite direction (either positive or negative) of the input value.

   NoteYou cannot use Invert in All mode.

Copying and Pasting Filter Settings

Use the Copy and Paste commands in the Filter Matrix menu to copy a setup from one filter and apply it to a custom filter. The Copy command copies the displayed matrix as well as the status of the Bypass Chroma and Bypass Luminance buttons.

To copy and paste filter settings:

1. Load the filter you want to modify.
2. Display the matrix setup you want to copy and click Copy.
3. Select the filter element to which you want to paste the settings: Filter 1, Filter 2, Filter 3, Filter 4, or Filter 5.
4. Select Matrix from the Filter Type box.
5. Click Paste.

   The setup you copied is pasted into the current filter element.