From 210b900d84dac8c967df5eb3bb53b781d93c6bbd Mon Sep 17 00:00:00 2001 From: nicolas Date: Mon, 10 Sep 2012 17:39:19 +0000 Subject: [PATCH] --- MagickCore/enhance.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/MagickCore/enhance.c b/MagickCore/enhance.c index 0a5b337c8..198f8cbf1 100644 --- a/MagickCore/enhance.c +++ b/MagickCore/enhance.c @@ -3315,7 +3315,7 @@ MagickExport MagickBooleanType SigmoidalContrastImage(Image *image, case values are left alone. */ /* - Sigmoidal function Sigmoidal with inflexion point moved to b and "slope + Sigmoidal function with inflexion point moved to b and "slope constant" set to a. The first version, based on the hyperbolic tangent tanh, when combined with the scaling step, is an exact arithmetic clone of the @@ -3326,11 +3326,10 @@ MagickExport MagickBooleanType SigmoidalContrastImage(Image *image, scaled sigmoidal derivation is invariant under affine transformations of the ordinate. The tanh version is almost certainly more accurate and cheaper. - The 0.5 factor in the argument is to clone the legacy ImageMagick - behavior. - The reason for making the define depend on atanh even though it only - uses tanh has to do with the construction of the inverse of the scaled - sigmoidal. + The 0.5 factor in its argument is to clone the legacy ImageMagick + behavior. The reason for making the define depend on atanh even + though it only uses tanh has to do with the construction of the + inverse of the scaled sigmoidal. */ #if defined(MAGICKCORE_HAVE_ATANH) #define Sigmoidal(a,b,x) ( tanh((0.5*(a))*((x)-(b))) ) -- 2.50.1