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Emphasis Parameter

The Emphasis parameter exclusively applies to the Emphasis lookup table definition method.

It allows transforming an image using a power-law expression:

Output = Inputγ

The γ – Gamma – exponent is mathematically linked to Emphasis by:

γ = 10-Emphasis

Emphasis Gamma Note
1.00 0.1

Max. Emphasis value; smallest γ value

0.00 1 Default Emphasis value; linear law
-1.00 10 Min. Emphasis value; largest γ value

To achieve a required given γ, Emphasis should be set to:

Emphasis = - log10γ

The following charts explain the emphasis effect for typical values of Emphasis and both values of Negative.