Merge pull request #956 from vighneshbirodkar/issue945

Equality of regionprops

skimage/measure/_regionprops.py

@@ -56,6 +56,8 @@ PROPS = {
     'WeightedNormalizedMoments': 'weighted_moments_normalized'
 }
 
+PROP_VALS = PROPS.values()
+
 
 class _cached_property(object):
     """Decorator to use a function as a cached property.
@@ -327,6 +329,20 @@ class _RegionProperties(MutableMapping):
                           category=DeprecationWarning)
             return getattr(self, PROPS[key])
 
+    def __eq__(self, other):
+        if not isinstance(other, _RegionProperties):
+            return False
+
+        for key in PROP_VALS:
+            try:
+                #so that NaNs are equal
+                np.testing.assert_equal(getattr(self, key, None),
+                                        getattr(other, key, None))
+            except AssertionError:
+                return False
+
+        return True
+
 
 def regionprops(label_image, properties=None,
                 intensity_image=None, cache=True):

skimage/measure/tests/test_regionprops.py

@@ -371,6 +371,22 @@ def test_invalid():
     assert_raises(AttributeError, get_intensity_image)
 
 
+def test_equals():
+    arr = np.zeros((100, 100), dtype=np.int)
+    arr[0:25, 0:25] = 1
+    arr[50:99, 50:99] = 2
+
+    regions = regionprops(arr)
+    r1 = regions[0]
+
+    regions = regionprops(arr)
+    r2 = regions[0]
+    r3 = regions[1]
+
+    assert_equal(r1 == r2, True, "Same regionprops are not equal")
+    assert_equal(r1 != r3, True, "Different regionprops are equal")
+
+
 if __name__ == "__main__":
     from numpy.testing import run_module_suite
     run_module_suite()