Add the perceptual difference metric to the rebaseline server

gm/rebaseline_server/imagediffdb_test.py

 #!/usr/bin/python
 
 """
 Copyright 2013 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 Test imagediffdb.py
 """
 
 # System-level imports
 import logging
 import shutil
 import tempfile
 import unittest
 
 # Local imports
 import imagediffdb
 
 
-IMG_URL_BASE = 'http://chromium-skia-gm.commondatastorage.googleapis.com/gm/bitmap-64bitMD5/'
+IMG_URL_BASE = ('http://chromium-skia-gm.commondatastorage.googleapis.com/gm/'
+                'bitmap-64bitMD5/')
 
 
 class ImageDiffDbTest(unittest.TestCase):
 
   def setUp(self):
     self._temp_dir = tempfile.mkdtemp()
     self.maxDiff = None
 
   def tearDown(self):
     shutil.rmtree(self._temp_dir)
@@ skipping 16 matching lines @@
     TODO(epoger): Instead of hitting Google Storage, we should read image
     files from local disk using a file:// IMG_URL_BASE.
     """
     # params for each self-test:
     # 0. expected image locator
     # 1. expected image URL
     # 2. actual image locator
     # 3. actual image URL
     # 4. expected percent_pixels_differing (as a string, to 4 decimal places)
     # 5. expected weighted_diff_measure (as a string, to 4 decimal places)
-    # 6. expected max_diff_per_channel
+    # 6. expected perceptual difference (as a string, to 4 decimal places)
+    # 7. expected max_diff_per_channel
     selftests = [
         [
             'arcofzorro/16206093933823793653',
             IMG_URL_BASE + 'arcofzorro/16206093933823793653.png',
             'arcofzorro/13786535001616823825',
             IMG_URL_BASE + 'arcofzorro/13786535001616823825.png',
-            '0.0662', '0.0113', [255, 255, 247],
+            '0.0662', '0.0113', '0.0662', [255, 255, 247],
         ],
         [
             'gradients_degenerate_2pt/10552995703607727960',
             IMG_URL_BASE + 'gradients_degenerate_2pt/10552995703607727960.png',
             'gradients_degenerate_2pt/11198253335583713230',
             IMG_URL_BASE + 'gradients_degenerate_2pt/11198253335583713230.png',
-            '100.0000', '66.6667', [255, 0, 255],
+            '100.0000', '66.6667', '100.0000', [255, 0, 255],
         ],
     ]
 
     # Add all image pairs to the database
     db = imagediffdb.ImageDiffDB(self._temp_dir)
     for selftest in selftests:
       retval = db.add_image_pair(
           expected_image_locator=selftest[0], expected_image_url=selftest[1],
           actual_image_locator=selftest[2],   actual_image_url=selftest[3])
 
     # Fetch each image pair from the database
     for selftest in selftests:
       record = db.get_diff_record(expected_image_locator=selftest[0],
                                   actual_image_locator=selftest[2])
       self.assertEqual('%.4f' % record.get_percent_pixels_differing(),
                        selftest[4])
       self.assertEqual('%.4f' % record.get_weighted_diff_measure(), selftest[5])
-      self.assertEqual(record.get_max_diff_per_channel(), selftest[6])
+      self.assertEqual('%.4f' % record.get_perceptual_difference(), selftest[6])
+      self.assertEqual(record.get_max_diff_per_channel(), selftest[7])
 
 
 def main():
   suite = unittest.TestLoader().loadTestsFromTestCase(ImageDiffDbTest)
   unittest.TextTestRunner(verbosity=2).run(suite)
 
 
 if __name__ == '__main__':
   main()