This is a simpler keying tool than the chroma key effect, and is used for removing green screen and blue screen backgrounds from video and images.
- Screen Color: Choose the color to be removed from your video.
- Red: Red screens are sometimes used for keying non-human subjects, such as mechanical models containing a lot of gray.
- Green: Green screen is the most common background for keying, because most video cameras record more data in the green channel than in the other color channels. It is also effective for human subjects, and provides for good separation from skin tones.
- Blue: Blue was the most common color for keying with film, due to the processed used for analog keying, and because it is most distinct from skin tones. It is still an effective option for video keying of human subjects, but is less common than green.
- Min: Increase the Min setting to remove a larger range of tones centered on the selected color.
- Max: Reduce the Max setting to restore edge areas to the matte. If the Max value is set below the Min value, the key will be inverted, and all colors except the selected color will be removed.
- Gamma: Shifts the gamma of the matte, which is an adjustment of the luminance which affects shadow tones more than highlight tones. In practice, increasing Gamma reduces the area removed by the key, and reducing the gamma increases what is removed.
- View Matte: Toggling this option displays the matte on the viewer, as a grayscale image where White is completely retained, and black is completely removed. This can be useful for identifying problem areas which may need further adjustment.