Image.sigmoidalContrast

Adjusts the contrast of an image channel with a non-linear sigmoidal contrast algorithm. Increases the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows.

class Image
void
sigmoidalContrast
(
double contrast = 3
,
double midpoint = 50
,
bool sharpen = false
,
)

Parameters

contrast
Type: double

indicates how much to increase the contrast (0 is none; 3 is typical; 20 is pushing it)

midpoint
Type: double

indicates where midtones fall in the resultant image (0 is white; 50% is middle-gray; 100% is black). Specify an apsulute number of pixels or an percentage by passing a value between 1 and 0

sharpen
Type: bool

Increase or decrease image contrast.

channel

The channels to adjust.

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