Garbage Matte
Often, the full extent of the backdrop is not covered by the green screen. Other elements may appear, which are removed using masks. A mask such as this is called a "Garbage matte".Launch After Effects.
Step1. Import the green screen media.
1.1. From the menu, choose "File", "Import", "File".
1.2. Navigate to the media folder containing the image sequence.
1.3. Click any image.
1.4. Make sure targa sequence is checked.
1.5. Click "Open".
1.6. In the Interpret footage panel Choose "Ignore" for Alpha.
1.7. Click "Okay".Step2. Interpret the footage correctly.
2.1. Right click on the footage in the project window.
2.2. From the pop-up choose "Interpret footage", "Main".
2.3. In the footage interpretation window, choose a frame rate of 25.
2.4. For the pixel aspect ratio choose the preset "D1/DV PAL Widescreen".Step3. Launch a new composition.
3.1. Choose the preset "PAL D1/DV Widescreen".
3.2. Change the frame rate to 25.
3.3. Use full resolution, start timecode 0, and a duration of 3 seconds.
3.4. Click Okay.Step4. Drag the green screen footage to the composition, where it snaps to the centre.Step4. Make a new layer as a temporary background.
4.1. From the menu choose "Layer", "New Solid".
4.2. Make it a c...
