triplet_to_brightness(): New function
diff --git a/Tools/pynche/ColorDB.py b/Tools/pynche/ColorDB.py
index fae0a3b..a4c8342 100644
--- a/Tools/pynche/ColorDB.py
+++ b/Tools/pynche/ColorDB.py
@@ -174,6 +174,15 @@
return map(operator.__div__, rgbtuple, _maxtuple)
+def triplet_to_brightness(rgbtuple):
+ # return the brightness (grey level) along the scale 0.0==black to
+ # 1.0==white
+ r = 0.299
+ g = 0.587
+ b = 0.114
+ return r*rgbtuple[0] + g*rgbtuple[1] + b*rgbtuple[2]
+
+
if __name__ == '__main__':
import string