Luma key – Apple Motion 4 User Manual

Page 1023

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Luma Key

Luma Key pulls a key from your object based on a selected brightness level. This can be
effective if you’re keying a subject that was shot against a solid white or black background,
and exposed so that there are no absolute highlights or shadows within the foreground
subject. Despite this, shadows and highlights in the image usually make this a difficult
filter with which to pull a perfect key.

Original image

Luma Key filter (set to Darker) applied

Parameters in the Inspector

Key Mode:

Sets the mode used to calculate the luminance value of your object. The

modes can be selected from the following: Key Out Brighter, Key Out Darker, Key Out
Similar, or Key Out Dissimilar.

Luminance:

Sets the type of luminance that is keyed. The types can be selected from

the following: NTSC, PAL, Film, Red, Green, or Blue.

Threshold:

Sets the threshold of the key.

Tolerance:

Sets the tolerance of the threshold. Larger values allow a greater difference

between the set key color and other color values that are incorporated into the key.

Mix:

Sets what percentage of the original image is blended with the keyed image.

HUD Controls
The HUD contains the following controls: Key Mode, Luminance, Threshold, and Tolerance.

1023

Chapter 16

Using Filters

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