From a56c6071c27a13818c051e949bc5e2f6a5d30331 Mon Sep 17 00:00:00 2001
From: emmanuelle <emmanuelle.gouillart@nsup.org>
Date: Wed, 23 Dec 2015 16:09:13 +0100
Subject: [PATCH 1/2] Corrected bug in the computation of the Euler
 characteristic.

---
 skimage/measure/_regionprops.py           | 2 +-
 skimage/measure/tests/test_regionprops.py | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/skimage/measure/_regionprops.py b/skimage/measure/_regionprops.py
index de523592..ddd0c8f5 100644
--- a/skimage/measure/_regionprops.py
+++ b/skimage/measure/_regionprops.py
@@ -125,7 +125,7 @@ class _RegionProperties(object):
     def euler_number(self):
         euler_array = self.filled_image != self.image
         _, num = label(euler_array, neighbors=8, return_num=True,
-                       background=-1)
+                       background=0)
         return -num + 1
 
     def extent(self):
diff --git a/skimage/measure/tests/test_regionprops.py b/skimage/measure/tests/test_regionprops.py
index 259967ea..919c0229 100644
--- a/skimage/measure/tests/test_regionprops.py
+++ b/skimage/measure/tests/test_regionprops.py
@@ -129,12 +129,12 @@ def test_equiv_diameter():
 
 def test_euler_number():
     en = regionprops(SAMPLE)[0].euler_number
-    assert en == 0
+    assert en == 1
 
     SAMPLE_mod = SAMPLE.copy()
     SAMPLE_mod[7, -3] = 0
     en = regionprops(SAMPLE_mod)[0].euler_number
-    assert en == -1
+    assert en == 0
 
 
 def test_extent():

From d62524f10369188b3956c669123b85b7a4078cec Mon Sep 17 00:00:00 2001
From: emmanuelle <emmanuelle.gouillart@nsup.org>
Date: Wed, 23 Dec 2015 16:26:23 +0100
Subject: [PATCH 2/2] Mentioned Euler characteristic (instead of Euler number)
 in docstring of regionprops.

---
 skimage/measure/_regionprops.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/skimage/measure/_regionprops.py b/skimage/measure/_regionprops.py
index ddd0c8f5..99258c66 100644
--- a/skimage/measure/_regionprops.py
+++ b/skimage/measure/_regionprops.py
@@ -340,7 +340,7 @@ def regionprops(label_image, intensity_image=None, cache=True):
     **equivalent_diameter** : float
         The diameter of a circle with the same area as the region.
     **euler_number** : int
-        Euler number of region. Computed as number of objects (= 1)
+        Euler characteristic of region. Computed as number of objects (= 1)
         subtracted by number of holes (8-connectivity).
     **extent** : float
         Ratio of pixels in the region to pixels in the total bounding box.