1 files changed, 18 insertions, 0 deletions
diff --git a/share/extensions/color_grayscale.py b/share/extensions/color_grayscale.py
new file mode 100755
index 0000000..5d134aa
--- /dev/null
+++ b/share/extensions/color_grayscale.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+"""Convert to grey"""
+
+import inkex
+
+
+class Grayscale(inkex.ColorExtension):
+    """Make all colours grayscale"""
+
+    def modify_color(self, name, color):
+        # ITU-R Recommendation BT.709 (NTSC and PAL)
+        # l = 0.2125 * r + 0.7154 * g + 0.0721 * b
+        lum = 0.299 * color.red + 0.587 * color.green + 0.114 * color.blue
+        return inkex.Color((int(round(lum)), int(round(lum)), int(round(lum))))
+
+
+if __name__ == "__main__":
+    Grayscale().run()