(PECL imagick 2.0.0)
Imagick::contrastImage — Change the contrast of the image
Esta función no está documentada actualmente, solamente se encuentra disponible la lista de parámetros.
Enhances the intensity differences between the lighter and darker elements of the image. Set sharpen to a value other than 0 to increase the image contrast otherwise the contrast is reduced.
The sharpen value
Returns TRUE on success.
Throws ImagickException on error.