Apple MA261Z/A User Manual - Page 682

Matte Filters Matte filters can be used by themselves to mask out areas of a clip, or to create alpha channel information for a clip to make a transparent border so that the clip can be composited against other layers. Matte filters can also be used to make further adjustments to layers with keying filters applied to them. For detailed information, see "Using Mattes to Add or Modify Alpha Channels" on page 822. Filter Eight-Point Garbage Matte Extract Four-Point Garbage Matte Image Mask Mask Feather Mask Shape Result Generates an eight-point polygon you can use to crop out portions of a clip. Eight-point controls allow you to define the polygonal matte. The Smooth slider rounds off the corners of the polygon to create rounder mattes. The Choke slider allows you to expand or contract the matte, and the Feather slider allows you to blur the edges of the matte. The Invert checkbox reverses what's matted and what's transparent, and the Hide Labels checkbox hides the number labels, which indicate which point of the matte corresponds to which point control of the filter. Produces a matte around the clip, similar to a Luma key. A View pop-up menu allows you to look at the source of the clip (with no key applied), the matte created by the filter, the final matted image, or a special composite of the source, matte, and final image for reference. Use the Threshold, Tolerance, and Softness sliders to adjust the matte. The Copy Result pop-up menu allows you to copy the luminance result to the RGB or alpha channel of your clip, and the Invert checkbox allows you to invert the result. Similar to the Eight-Point Garbage matte, but it creates a four-point polygonal matte. Takes the alpha channel or luminance from another clip and uses it to create a matte for the current clip. The Mask clip control allows you to select the clip from which to take the alpha channel or luminance values. The Channel pop-up menu lets you choose whether to use the clip's alpha channel or luminance level. The Invert checkbox allows you to invert the resulting matte. This filter is especially useful for taking custom edge masks that you can create with any image editor and applying them to clips in your sequence that you want to matte the edges out of. Unlike the Travel Matte composite mode, the Image Mask filter attaches a matte to the selected clip. You can use motion effects to move the affected clip around, and the matte follows. Blurs the alpha channel of the clip by the amount you specify with the Soft slider. Generates a mask shape to use to matte out the clip. You can choose a diamond, oval, rectangle, or round rectangle from the Shape pop-up menu. Use the Horizontal Scale and Vertical Scale sliders to adjust the size and aspect ratio of your mask shape. The Center point control allows you to specify the center of the mask, and an Invert checkbox lets you reverse what's transparent and what's solid. 682 Part IX Effects