See Source File
Mike Wey
This is an translation of the sigmoidal contrast example that can be found on the ImageMagick website: http://www.imagemagick.org/source/core/sigmoidal-contrast.c
Mainly to demonstrate the parallel execution of the foreach over the ImageView, normaly you whould use Image.sigmoidalContrast.
zlib (See accompanying LICENSE file)
Mike Wey 2011