Add a PNG conversion script

Author: deshipu

Diff for: png16.py

@@ -0,0 +1,14 @@
+"""
+Converts images to the 4-bit PNG format required by Stage.
+"""
+
+import sys
+from PIL import Image
+
+
+filename = sys.argv[1]
+image = Image.open(filename)
+image = image.convert(mode='P', dither=Image.Dither.NONE,
+                      palette=Image.Palette.ADAPTIVE, colors=16)
+filename = filename.rsplit('.', 1)[0] + '.png'
+image.save(filename, 'png', bits=4)