htpp

commit ae25790e98aecec6fea23cf4d4d040a541f7b8b4
parent a60a58d4e0cf5a7e684e0c7243a5b619b34a5b9e
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Thu,  4 Jun 2020 17:13:45 +0200

Apply the exposure to the "white" normalization factor

Diffstat:
M
doc/htpp.1.txt
 | 
2
+-
M
src/htpp.c
 | 
2
+-

2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/doc/htpp.1.txt b/doc/htpp.1.txt
@@ -42,7 +42,7 @@ the third and the fifth components of each *htrdr-image*(5) pixel encode a
 color with respect to the  CIE 1931 XYZ color space. *htpp* first tone maps
 these colors with the following filmic tone mapping operator [2]:
 
-    out-color = f(in-color * exposure) / f(white-scale)
+    out-color = f(in-color * exposure) / f(white-scale * exposure)
 
 with:
 
diff --git a/src/htpp.c b/src/htpp.c
@@ -494,7 +494,7 @@ filmic_tone_mapping
   const double F = 0.30;
   const double W = Ymax;
   #define TONE_MAP(X) ((((X)*(A*(X)+C*B)+D*E)/((X)*(A*(X)+B)+D*F))-E/F)
-  const double white_scale = TONE_MAP(W);
+  const double white_scale = TONE_MAP(W*exposure);
   ASSERT(pixel);
 
   pixel[PIXCPNT_X] = TONE_MAP(pixel[PIXCPNT_X]*exposure) / white_scale;