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Imagick::sigmoidalContrastImage

Adjusts the contrast of an image ()
bool Imagick::sigmoidalContrastImage ( bool sharpen, float alpha, float beta [, int channel] )

Warning:

This function is currently not documented; only the argument list is available.

Warning:

This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change without notice in a future release of PHP. Use this function at your own risk.

Adjusts the contrast of an image with a non-linear sigmoidal contrast algorithm. Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows. Contrast indicates how much to increase the contrast (0 is none; 3 is typical; 20 is pushing it); mid-point indicates where midtones fall in the resultant image (0 is white; 50 is middle-gray; 100 is black). Set sharpen to true to increase the image contrast otherwise the contrast is reduced.

Parameters

sharpen
alpha
beta
channel

Return Values

Returns TRUE on success.