Posted: 2006-04-27T10:11:10-07:00
Try MagickLevelImageChannel(). It permits you to specify the white and black points. You could also try MagickSigmoidalContrastChannel().
Use https://github.com/ImageMagick/ImageMagick/discussions instead.
https://download.imagemagick.org/discourse-server/
https://download.imagemagick.org/discourse-server/viewtopic.php?t=6468