• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL

Lesson 13. Applying Filters > Matting Portions of an Image

Matting Portions of an Image

Mattes are filters that mask out a portion of an image. They can be used to create a simple letterbox or wide-screen effect for your entire sequence, or to mask a portion of an image you don't want to see, perhaps because of an unwanted object in the background. In fact, some mattes are referred to as garbage mattes for this reason. When you add a matte to create a wide-screen effect, you can save several steps by combining the video clips into a nest, and then applying the matte to the nested sequence.

From the Browser, open the Intro with Matte sequence, and play it.

To matte or mask the number information in the images and to see a letterbox or widescreen version of this sequence, you could add a matte filter to each clip. But then, if you wanted to make a change to the matte parameters, you would have to change the parameters for each clip. An easier way is to create a nest of the video clips.

Select all the video clips in this sequence. Choose Sequence > Nest Items, or press Option-C. In the Nest Items window, enter the name Intro NEST, and click OK.

In the Timeline, one single clip appears where the individual clips used to be. This is a nest of the clips you selected. In the Browser, there is a new Intro NEST sequence.


If you want to get back to the individual clips, just double-click the sequence in the Browser, or the nest in the Timeline, and a sequence opens with just the individual clips you nested together.

To apply a matte to the nest of clips, select the nest in the Timeline, and choose Effects > Video Filters > Mattes > Widescreen. Drag the playhead through the sequence.

The upper and lower portions of the video clips have been equally masked, and you no longer see the numbers on the images.

To adjust the Matte filter settings, you can't double-click the nest in the Timeline, as you would a clip, or the nested sequence would open with the individual clips. Press Option and double-click the nest in the Timeline. In the Viewer, drag the playhead through the scrubber bar.

The entire nest of all the individual clips, including transitions, appears in the Viewer.


There are other ways to open a nest from the Timeline into the Viewer. You can Ctrl-click the nest and choose Open in Viewer, select the nest and press Return, or drag the nest from the Timeline to the Viewer.

Click the Filters tab. In the Matte parameters, click the Type pop-up and choose 2:35:1, and watch the sequence.

Because the clips are nested, you have to make only one selection in one filter to change the matte option.


Each matte option is an aspect ratio that represents the image's width by its height. 35mm film is generally 1.85:1. The A Thousand Roads film is screening at the Smithsonian National Museum of the American Indian in an aspect ratio of 2.35:1.

To apply a different kind of Matte filter, open the Garbage Matte sequence from the Browser, and drag the playhead through this clip.

This is the freeze-frame you used in the previous lesson. Let's say the producer wants you to remove the man in the lower-left corner. Cropping the image from the bottom or side won't work here because it will crop the entire bottom or left edge of the image.

Double-click the MB long run FREEZE clip to open it in the Viewer. Click the Filters tab, and choose Effects > Video Filters > Matte > Four-Point Garbage Matte.

In the parameters area of this filter are four points. In the Canvas window, the default points are set in each of the corners and are numbered clockwise from the upper-left corner. You will set new points to create a box around the man's body.

To set the first point of the matte, click the crosshair in the Point 1 parameter line. Move the pointer into the Canvas, and click to the left of the man's body, above his head.


If you click and drag the point before releasing the mouse, the point will continuously update. If you release the mouse, you have to click the Point 1 crosshair again in the Filters tab and repeat the step.

Continue setting Points 2, 3, and 4 clockwise around the man to isolate him. Also, drag Points 3 and 4 down beneath the image to include the area up to the clip's edge.

With the points isolating just the man, which is the portion of the image you don't want, you can now invert the image to reverse the matte.

In the Four-Point Garbage Matte filter, click the Invert check box, and drag the Feather slider to the right to 30. You may have to readjust the points to completely eliminate the man from the picture.

Now you need to fill the hole. You do this by placing a clip beneath the current one so material from that clip will show through. You can use a duplicate of this clip as the background image and adjust it as necessary.

With the MB long run FREEZE clip selected in the Timeline, press Option and drag the copy down to the V1 track, release the Option key, then release the clip.

Press W to toggle on Image+Wireframe mode. In the Canvas, with the V1 clip selected, drag the wireframe left until you see a good match to fill thehole. You can also rotate the V1 image slightly to match the angle of the racing track. Toggle off the wireframe mode.


If the matte points are visible in the image area, double-click the V2 clip. In the 4-Point Garbage Matte parameters, click the View Mode and choose Final.



Not a subscriber?

Start A Free Trial

  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint