Add shape masks to a color mask
Often when you create a color mask, more areas of the video are affected by it than you would like. For example, there might be a gray car on the right side of the screen that you want to color correct, and a gray car on the left that you don’t want to affect. In this situation, you can add one or more shape masks to restrict the color mask to the areas defined by the shape masks.
You can set masks to interact in different ways using mask blend modes. For example, you can add mask shapes together to create a combined mask, subtract a mask shape from other masks, and intersect masks. For a complete description of mask blend modes, see Combine multiple masks on a video effect.
There are many uses for multiple masks in a color correction. The example below shows how you might use a shape mask to isolate an area of a color mask: the dark gray body color of one car in a line of four similarly colored cars.
Example: Add shape masks to a color mask in a Color Correction effect
If the Video inspector is not already visible, do one of the following:
Choose Window > Show Inspector (or press Command-4).
Click the Inspector button in the toolbar.
Click the Video button at the top of the Inspector pane to open the Video inspector.
The Video inspector appears with the Color Correction in the Effects section.
Apply a color mask to the color correction.
In the Effects section of the Video inspector, click View Masks (next to the effect name).
The color mask alpha channel appears in the Viewer.
Note: If necessary, you can invert the mask selection. For more information, see Invert effect masks for a clip.
Apply a shape mask to the same color correction.
Both masks appear in a list below the effect name in the Video inspector.
By default, the shape mask appears at the top of the list in the Video inspector, set to the Add blend mode. The color mask’s blend mode is changed to Intersect. (In Intersect mode, only the area inside the mask shape that overlaps with other mask shapes is affected.)
Click the Shape Mask Onscreen Controls button so that the onscreen controls appear in the Viewer.
Adjust the shape mask onscreen controls to isolate the area you want to correct (in this example, the dark gray tones of the first car).
The alpha channel in the Viewer shows the isolated area only.
Add additional shape masks as needed to further isolate the area.
Click the Color Board button in the Video inspector and color correct the isolated area.