[babl] base: For RGB->Y, use sRGB primaries that are adapted to a D50 illuminant.

[Michael Henning <mhenning src gnome org>]

commit d3e75895a994fa87640cf04c27314b1ff935675c
Author: Michael Henning <drawoc darkrefraction com>
Date:   Sun Sep 29 12:48:04 2013 -0400

    base: For RGB->Y, use sRGB primaries that are adapted to a D50 illuminant.
    
    Thanks to Elle Stone for pointing this out.

 babl/base/rgb-constants.h |   29 ++++++++++++-----------------
 1 files changed, 12 insertions(+), 17 deletions(-)
---
diff --git a/babl/base/rgb-constants.h b/babl/base/rgb-constants.h
index 8f8b410..0e47056 100644
--- a/babl/base/rgb-constants.h
+++ b/babl/base/rgb-constants.h
@@ -16,21 +16,16 @@
  * <http://www.gnu.org/licenses/>.
  */
 
-#if 0
-#define CONTEMPORARY_MONITOR
-#endif
+/*
+ * These primaries have been adapted for a D50 illuminant.
+ *
+ * They were taken from here:
+ * http://www.brucelindbloom.com/WorkingSpaceInfo.html#AdaptedPrimaries
+ *
+ * For more information, see this thread:
+ * https://mail.gnome.org/archives/gimp-developer-list/2013-September/msg00113.html
+ */
 
-#ifdef CONTEMPORARY_MONITOR
-  /* source: http://www.poynton.com/ColorFAQ.html */
-  #define RGB_LUMINANCE_RED    (0.212671)
-  #define RGB_LUMINANCE_GREEN  (0.715160)
-  #define RGB_LUMINANCE_BLUE   (0.072169)
-#else
-  /* this is not correct, but the constants are kept around */
-  #define RGB_LUMA_RED         (0.299)
-  #define RGB_LUMA_GREEN       (0.587)
-  #define RGB_LUMA_BLUE        (0.114)
-  #define RGB_LUMINANCE_RED    RGB_LUMA_RED
-  #define RGB_LUMINANCE_GREEN  RGB_LUMA_GREEN
-  #define RGB_LUMINANCE_BLUE   RGB_LUMA_BLUE
-#endif
+#define RGB_LUMINANCE_RED    (0.222491)
+#define RGB_LUMINANCE_GREEN  (0.716888)
+#define RGB_LUMINANCE_BLUE   (0.060621)