Lumakey

Lumakey

Status:

Maintained

Keyframes:

No

Source library:

MLT

Source filter:

lumakey

Available:

On Master only:

No

Known bugs:

No

Description

This filter modifies the image’s alpha channel as a function of its luma value. This is used together with a compositor to combine two images so that bright or dark areas of source image are overwritten on top of the destination image.

Parameters

Parameter	Value	Description
Threshold	Integer	Luma value that defines the center point of transition from prelevel to postlevel opacity value.
Slope	Integer	Defines the width of the transition from prelevel to postlevel luma value. Start point of transition in opacity value is threshold - slope and end point is thresholt + slope, values are forced in range 0 - 255.
Pre-Threshold Luma Level	Integer	Opacity value before the transition in opacity value begins
Pre-Threshold Luma Level	Integer	Opacity value after the transition in opacity value ends