From: nicolas <nicolas@git.imagemagick.org>
Date: Wed, 1 Aug 2012 20:02:20 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: 7.0.1-0~5211
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=0f6c5d810d279a365f4bc999e9186d643f397f21;p=imagemagick

---

diff --git a/MagickCore/enhance.c b/MagickCore/enhance.c
index ee440915d..0371dd0a9 100644
--- a/MagickCore/enhance.c
+++ b/MagickCore/enhance.c
@@ -3389,9 +3389,9 @@ MagickExport MagickBooleanType SigmoidalContrastImage(Image *image,
 	 * 'flatline' handling (greyscale):
          *
 	 * (1/(1+exp(a*(b-u))) - (1/(1+exp(a*b)) + 1/(1+exp(a*(b-1))))/2 )
-         * / (1/(1+exp(a*(b-1))) - 1/(1+exp(a*b)) + epsilon )
+         * / (1/(1+exp(a*(b-1))) - 1/(1+exp(a*b)) + epsilon ) + 0.5
          *
-	 * "+0.5" is to center things around the middle of the Quantum
+	 * "+ 0.5" is to center things around the middle of the Quantum
 	 * range.
 	 *
 	 * "+epsilon" is to allow a=0 without division by zero.