# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444134714 -7200
# Node ID 9a8c24425be97b0590dc60d95b90f88166ffae31
# Parent  2e2722f377b05cbf3a7de07d86000f256036f1d2
Introduced compensation to complementary colours for those removed.

diff -r 2e2722f377b0 -r 9a8c24425be9 optimiser.py
--- a/optimiser.py	Sun Oct 04 21:47:16 2015 +0200
+++ b/optimiser.py	Tue Oct 06 14:31:54 2015 +0200
@@ -59,6 +59,16 @@
         d[(255, 255, 255)] += common
     return [(f, value) for value, f in d.items()]
 
+def compensate(d, chosen):
+    dd = dict([(value, f) for f, value in d])
+    for f, value in d:
+        if value not in chosen:
+            _value, complement = complements(value)
+            if complement in chosen:
+                f = max(0, f - dd[complement])
+                dd[value] = f
+    return [(f, value) for value, f in dd.items() if value in chosen]
+
 def combine(d):
     out = [0, 0, 0]
     for v, rgb in d:
@@ -67,15 +77,19 @@
         out[2] += v * rgb[2]
     return out
 
-def pattern(rgb):
+def pattern(rgb, chosen=None):
     l = combination(rgb)
+    if chosen:
+        l = compensate(l, chosen)
     l.sort(reverse=True)
     return l
 
-def get_value(rgb):
-    choose = random()
+def get_value(rgb, chosen=None):
+    l = pattern(rgb, chosen)
+    limit = sum([f for f, c in l])
+    choose = random() * limit
     threshold = 0
-    for f, c in pattern(rgb):
+    for f, c in l:
         threshold += f
         if choose < threshold:
             return c
@@ -147,6 +161,7 @@
     desaturate = sys.argv[3:].count("-d")
     preview = "-p" in sys.argv[3:]
     square = "-2" in sys.argv[3:] and square or (lambda x: x)
+    randomise = "-R" in sys.argv[3:]
 
     x = EXIF.process_file(open(input_filename))
     im = PIL.Image.open(input_filename).convert("RGB")
@@ -192,7 +207,7 @@
         most = [value for n, value in c[:4]]
         least = [value for n, value in c[4:]]
 
-        if least:
+        if least and randomise:
             switched = []
             for j in 1, 2:
                 i = randrange(0, 4)
@@ -206,14 +221,7 @@
 
         for x in range(0, width):
             rgb = im.getpixel((x, y))
-
-            # Get the requested colours and choose the closest alternative for
-            # less common colours.
-
-            value = get_value(rgb)
-            if value in least:
-                value = nearest(value, most)
-
+            value = get_value(rgb, most)
             im.putpixel((x, y), value)
 
     im.save(output_filename)