Fixed color comparison

2 files changed, 146 insertions, 10 deletions

diff --git a/tools/python/transit/transit_color_palette.py b/tools/python/transit/transit_color_palette.py
index 054dfd92ae..df44ce69bf 100644
--- a/tools/python/transit/transit_color_palette.py
+++ b/tools/python/transit/transit_color_palette.py
@@ -1,3 +1,5 @@
+import math
+
 def to_rgb(color_str):
     if len(color_str) != 6:
         return (0, 0, 0)
@@ -7,6 +9,90 @@ def to_rgb(color_str):
     return (r, g, b)
 
 
+def blend_colors(rgb_array1, rgb_array2, k):
+    return (rgb_array1[0] * (1.0 - k) + rgb_array2[0] * k,
+            rgb_array1[1] * (1.0 - k) + rgb_array2[1] * k, 
+            rgb_array1[2] * (1.0 - k) + rgb_array2[2] * k)
+
+
+def rgb_pivot(n):
+    result = n / 12.92
+    if n > 0.04045:
+        result = ((n + 0.055) / 1.055) ** 2.4
+    return result * 100.0;
+
+
+def to_xyz(rgb_array):
+    r = rgb_pivot(rgb_array[0] / 255.0);
+    g = rgb_pivot(rgb_array[1] / 255.0);
+    b = rgb_pivot(rgb_array[2] / 255.0);
+    return (r * 0.4124 + g * 0.3576 + b * 0.1805,
+            r * 0.2126 + g * 0.7152 + b * 0.0722,
+            r * 0.0193 + g * 0.1192 + b * 0.9505)
+
+
+#https://en.wikipedia.org/wiki/Lab_color_space#CIELAB
+def lab_pivot(n):
+    if n > 0.008856:
+        return n ** (1.0/3.0)
+    return (903.3 * n + 16.0) / 116.0
+
+
+def to_lab(rgb_array):
+    xyz = to_xyz(rgb_array)
+    x = lab_pivot(xyz[0] / 95.047)
+    y = lab_pivot(xyz[1] / 100.0)
+    z = lab_pivot(xyz[2] / 108.883)
+    l = 116.0 * y - 16.0
+    if l < 0.0:
+        l = 0.0
+    a = 500.0 * (x - y)
+    b = 200.0 * (y - z)
+    return (l, a, b)
+
+
+def lum_distance(ref_color, src_color):
+    return 30 * (ref_color[0] - src_color[0]) ** 2 +\
+           59 * (ref_color[1] - src_color[1]) ** 2 +\
+           11 * (ref_color[2] - src_color[2]) ** 2
+
+
+def is_bluish(rgb_array):
+    d1 = lum_distance((255, 0, 0), rgb_array)
+    d2 = lum_distance((0, 0, 255), rgb_array)
+    return d2 < d1
+
+
+#http://en.wikipedia.org/wiki/Color_difference#CIE94
+def cie94(ref_color, src_color):
+    lab_ref = to_lab(ref_color)
+    lab_src = to_lab(src_color)
+    deltaL = lab_ref[0] - lab_src[0]
+    deltaA = lab_ref[1] - lab_src[1]
+    deltaB = lab_ref[2] - lab_src[2]
+    c1 = math.sqrt(lab_ref[0] * lab_ref[0] + lab_ref[1] * lab_ref[1])
+    c2 = math.sqrt(lab_src[0] * lab_src[0] + lab_src[1] * lab_src[1])
+    deltaC = c1 - c2
+    deltaH = deltaA * deltaA + deltaB * deltaB - deltaC * deltaC
+    if deltaH < 0.0:
+        deltaH = 0.0
+    else:
+        deltaH = math.sqrt(deltaH)
+    # cold tones if a color is more bluish.
+    Kl = 1.0
+    K1 = 0.045
+    K2 = 0.015
+    sc = 1.0 + K1 * c1
+    sh = 1.0 + K2 * c1
+    deltaLKlsl = deltaL / Kl
+    deltaCkcsc = deltaC / sc
+    deltaHkhsh = deltaH / sh
+    i = deltaLKlsl * deltaLKlsl + deltaCkcsc * deltaCkcsc + deltaHkhsh * deltaHkhsh
+    if i < 0:
+        return 0.0
+    return math.sqrt(i)
+
+
 class Palette:
     def __init__(self, colors):
         self.colors = {}
@@ -16,16 +102,26 @@ class Palette:
     def get_default_color(self):
         return 'default'
 
-    def get_nearest_color(self, color_str):
+    def get_nearest_color(self, color_str, casing_color_str, excluded_names):
         """Returns the nearest color from the palette."""
         nearest_color_name = self.get_default_color()
         color = to_rgb(color_str)
+        if (casing_color_str is not None and len(casing_color_str) != 0):
+            color = blend_colors(color, to_rgb(casing_color_str), 0.5)
         min_diff = None
+
+        bluish = is_bluish(color)
         for name, palette_color in self.colors.iteritems():
-            diff = 30 * (palette_color[0] - color[0]) ** 2 +\
-                   59 * (palette_color[1] - color[1]) ** 2 +\
-                   11 * (palette_color[2] - color[2]) ** 2
+            if name in excluded_names:
+                continue
+            if bluish:
+                diff = lum_distance(palette_color, color)
+            else:
+                diff = cie94(palette_color, color)
             if min_diff is None or diff < min_diff:
                 min_diff = diff
                 nearest_color_name = name
+        # Left here for debug purposes. 
+        #print("Result: " + color_str + "," + str(casing_color_str) +
+        #      " - " + nearest_color_name + ": bluish = " + str(bluish))
         return nearest_color_name
diff --git a/tools/python/transit/transit_graph_generator.py b/tools/python/transit/transit_graph_generator.py
index cc9e407474..acf6091416 100755
--- a/tools/python/transit/transit_graph_generator.py
+++ b/tools/python/transit/transit_graph_generator.py
@@ -6,6 +6,7 @@ import copy
 import json
 import math
 import matplotlib.pyplot as plt
+import matplotlib.patches as patches
 import numpy as np
 import os.path
 import sys, io
@@ -70,6 +71,7 @@ class TransitGraphBuilder:
         self.segments = {}
         self.shapes = []
         self.transit_graph = None
+        self.matched_colors = {}
 
     def __get_average_stops_point(self, stop_ids):
         """Returns an average position of the stops."""
@@ -176,10 +178,7 @@ class TransitGraphBuilder:
                             'interval': line_item['interval'],
                             'stop_ids': []
                             }
-                    if 'colour' in route_item:
-                        line['color'] = self.palette.get_nearest_color(route_item['colour'])
-                    else:
-                        line['color'] = self.palette.get_default_color()
+                    line['color'] = self.__match_color(route_item.get('colour', ''), route_item.get('casing', ''))
 
                     # TODO: Add processing of line_item['shape'] when this data will be available.
                     # TODO: Add processing of line_item['trip_ids'] when this data will be available.
@@ -203,6 +202,17 @@ class TransitGraphBuilder:
                     self.lines.append(line)
                     line_index += 1
 
+    def __match_color(self, color_str, casing_str):
+        if len(color_str) == 0:
+            return self.palette.get_default_color()
+        matched_colors_key = color_str + "/" + casing_str
+        if matched_colors_key in self.matched_colors:
+            return self.matched_colors[matched_colors_key]
+        c = self.palette.get_nearest_color(color_str, casing_str, self.matched_colors.values())
+        if c != self.palette.get_default_color():
+            self.matched_colors[matched_colors_key] = c
+        return c
+            
     def __generate_transfer_nodes(self):
         """Merges stops into transfer nodes."""
         for edge in self.edges:
@@ -332,6 +342,27 @@ class TransitGraphBuilder:
             plt.scatter([point['x']], [point['y']], size, color)
         plt.show()
 
+    def show_color_maching_table(self, title, colors_ref_table):
+        fig = plt.figure()
+        ax = fig.add_subplot(111, aspect='equal')
+        plt.title(title)
+        sz = 1.0 / (2.0 * len(self.matched_colors))
+        delta_y = sz * 0.5
+        for c in self.matched_colors:
+            tokens = c.split('/')
+            if len(tokens[1]) == 0:
+                tokens[1] = tokens[0]
+            ax.add_patch(patches.Rectangle((sz, delta_y), sz, sz, facecolor="#" + tokens[0], edgecolor="#" + tokens[1]))
+            rect_title = tokens[0]
+            if tokens[0] != tokens[1]:
+                rect_title += "/" + tokens[1]
+            ax.text(2.5 * sz, delta_y, rect_title + " -> ")
+            ref_color = colors_ref_table[self.matched_colors[c]]
+            ax.add_patch(patches.Rectangle((0.3 + sz, delta_y), sz, sz, facecolor="#" + ref_color))
+            ax.text(0.3 + 2.5 * sz, delta_y, ref_color + " (" + self.matched_colors[c] + ")")
+            delta_y += sz * 2.0
+        plt.show()
+
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()
@@ -342,6 +373,9 @@ if __name__ == '__main__':
                         help='transit colors file COLORS_FILE_PATH', metavar='COLORS_FILE_PATH')
     parser.add_argument('-p', '--preview', action="store_true", default=False,
                         help="show preview of the transit scheme")
+    parser.add_argument('-m', '--matched_colors', action="store_true", default=False,
+                        help="show the matched colors table")
+
 
     parser.add_argument('-a', '--alpha', type=float, default=0.5, help='the curves generator parameter value ALPHA',
                         metavar='ALPHA')
@@ -360,9 +394,9 @@ if __name__ == '__main__':
     result = transit.build()
 
     output_file = args.output_file
+    head, tail = os.path.split(os.path.abspath(args.input_file))
+    name, extension = os.path.splitext(tail)
     if output_file is None:
-        head, tail = os.path.split(os.path.abspath(args.input_file))
-        name, extension = os.path.splitext(tail)
         output_file = os.path.join(head, name + '.transit' + extension)
     with io.open(output_file, 'w', encoding='utf8') as json_file:
         result_data = json.dumps(result, ensure_ascii=False, indent=4, sort_keys=True)
@@ -371,3 +405,9 @@ if __name__ == '__main__':
 
     if args.preview:
         transit.show_preview()
+
+    if args.matched_colors:
+        colors_ref_table = {}
+        for color_name, color_info in colors['colors'].iteritems():
+            colors_ref_table[color_name] = color_info['clear']
+        transit.show_color_maching_table(name, colors_ref_table)