Imagick::sigmoidalContrastImage

(no version information, might be only in CVS)

Imagick::sigmoidalContrastImage -- Adjusts the contrast of an image

Description

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

Its description

alpha

Its description

beta

Its description

channel

Its description

Return Values

Returns TRUE on success.