fix bug in color conversion

diff --git a/TODO b/TODO
index 3c4e5ad..4c022c6 100644 (file)
--- a/TODO
+++ b/TODO
@@ -6,3 +6,4 @@ faster (and more realiable) grid search
 stone finding
 better user interface
 faster image processing
+use floats in computations

diff --git a/imago_pack/intrsc.py b/imago_pack/intrsc.py
index d26bea4..ce89cb2 100644 (file)
--- a/imago_pack/intrsc.py
+++ b/imago_pack/intrsc.py
@@ -108,6 +108,14 @@ def intersections_from_angl_dist(lines, size, get_all=True):
         intersections.append(line)
     return intersections
    
+def RGBtoSat(c):
+    max_diff = max(c) - min(c)
+    if max_diff == 0:
+        return 0
+    else:
+        #TODO simplify this
+        return max_diff / float(255. - abs(max(c) + min(c) - 255))
+
 def stone_color_raw(image, (x, y)):
     """Given image and coordinates, return stone color."""
     suma = []
@@ -119,8 +127,7 @@ def stone_color_raw(image, (x, y)):
                 pass
     luma = sum([0.30 * sum(s[0] for s in suma) / 25., 0.59 * sum(s[1] for s in suma) / 25., 
             0.11 * sum(s[2] for s in suma) / 25.]) / 255.
-    saturation = sum(max(s) - min(s) / float(255. - abs(max(s) + min(s) - 255))
-                     for s in suma) / (25. * 255.)
+    saturation = sum(RGBtoSat(s) for s in suma) / (25. * 255.)
     color = [sum(s[0] for s in suma) / 25., sum(s[1] for s in suma) / 25.,
              sum(s[2] for s in suma) / 25.]
     return luma, saturation, color