LumaKey
Function
This creates a key in the alpha channels based on overall luminance. Values
below loVal are set to zero, and values above hiVal are
set to 1. Values in between are ramped. You also have roll-off control,
plus a mMult toggle.
This is a fast way to place the luminance of the image into the alpha
layer, but this could also be done with a Reorder - rgbl.
Parameters
|
Type
|
Defaults
|
Function
|
loVal |
float
|
0 |
Any pixel below this value (as calculated
per its luminance) turns black. |
hiVal |
float
|
1 |
Any pixel above this value (as calculated
by its luminanace) turns white. |
lo,hiSmooth |
float
|
0,0, |
A rolloff factor to provide a smooth dropoff.
|
mMult |
int
|
0 |
automatic pre-multiplification of the RGB channels.
0 = no pre-multiply
1 = pre-multiply
|
Synopsis
image LumaKey(
image,
float loVal,
float hiVal,
float loSmooth,
float hiSmooth,
int mMult
);
Script
image = LumaKey(
image,
loVal,
hiVal,
loSmooth,
hiSmooth,
mMult
);
Command Line
shake -lumakey loVal hiVal loSmooth etc...
See Also
ChromaKey, DepthKey,
Primatte
|