# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1443658406 -7200
# Node ID ac7b9012ab35f99a49021b01d5a35907a8a8e013
# Parent  99d5a002b1ce54b1e6ea56cc611437bce52b7bf6
Added image saturation support.

diff -r 99d5a002b1ce -r ac7b9012ab35 optimiser.py
--- a/optimiser.py	Wed Sep 30 18:19:47 2015 +0200
+++ b/optimiser.py	Thu Oct 01 02:13:26 2015 +0200
@@ -65,6 +65,15 @@
 def get_best(rgb, values):
     return nearest(rgb, values)[0][1]
 
+def sign(x):
+    return x >= 0 and 1 or -1
+
+def saturate(rgb):
+    return tuple(map(saturate_value, rgb))
+
+def saturate_value(x):
+    return 127.5 + sign(x - 127.5) * 127.5 * math.sqrt(abs(x - 127.5) / 127.5)
+
 def test():
     size = 512
     for r in (0, 63, 127, 191, 255):
@@ -108,6 +117,7 @@
 
     input_filename, output_filename = sys.argv[1:3]
     rotate = "-r" in sys.argv[3:]
+    saturate = "-s" in sys.argv[3:]
 
     x = EXIF.process_file(open(input_filename))
     im = PIL.Image.open(input_filename)
@@ -121,6 +131,8 @@
         c = {}
         for x in range(0, width):
             rgb = im.getpixel((x, y))
+            if saturate:
+                rgb = saturate(rgb)
             value = get_value((x, y), rgb, width, height)
             im.putpixel((x, y), value)
             if not c.has_key(value):