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Basic Keyer

Brief Description

A Basic Luminance Keyer, which computes the key color from the RGB values of the image. From the key color, a background transparancy is computed. For example, is is useful to mask out a sky which is almost always the brightest thing in the image.


Parameter / Script Name Type Default Function
Enabled / enabled Boolean On
Mode / mode Choice Luminance
- Luminance: Uses the source pixel luminance to pull a key
- Color: Uses the source pixel color to pull a key
- Screen: Uses a color difference between the max component minus the other components for keying
- None: Only despill is applied to RGB. You can control despill areas using the inside matte, or use with Alpha Mode set to Add to Inside Matte. If Output is set to Unpremultiplied, this despills the image even if no mask is present
Luminance Mode / luma_formula Choice Rec. 709 Luminance formula used when mode is not None
- Rec. 709
- Rec. 2020
- ACES ap-0
- ACES ap-1
- CCIR 601
- Average: Average of intensities
- Max: Maximum of intensities
Alpha Mode / alpha_mode Choice Ignore Source Alpha
- Ignore Source Alpha
- Add To Inside Matte: The source alpha channel is added to the inside matte. This is useful for multi-pass keying
- Normal: The foreground key is multiplied by thee source alpha
Output / output_mode Choice Premultiplied
- Source Color + Key Alpha: Outputs the source color and alpha of the foreground key. Useful for multi-pass keying
- Premultiplied: Color is the source color after key color suppression, multiplied by alpha. Alpha is the foreground key
- Key: Foreground key is output in RGBA channels
Key Color / key_color Color 0, 1, 0, 1
Lower Softness / lower_softness Float -0.5 Background key value goes from 0 to 1 when foreground key is over this range
Lower Tolerance / lower_tolerance Float 0 Background key value is 1 when foreground key is over this range
Center / center Float 1 Foreground key value forresponding to the key color, where the background key should be 1
Upper Softness / upper_softness Float 0.5 Background key value goes from 1 to 0 when foreground key is over this range
Upper Tolerance / upper_tolerance Float 0 Background key value is 1 when foreground key is over this range
Despill / despill Float 1 Reduces color spill on the foreground. When between 0 and 1, only mixed regions are despilled. Above 1, foreground regions are despilled too
Despill Angle / despill_angle Float 120 Opening of the cone centered around the keyColor where colors are despilled. A wider angle means that more colors are affected
Inside Matte / inside_matte Image -
Outside Matte / outside_matte Image -