Merge pull request #641 from sciunto/example_ht

Example Hough transform (ellipse)

skimage/data/__init__.py

@@ -184,3 +184,16 @@ def chelsea():
 
     """
     return load("chelsea.png")
+
+
+def coffee():
+    """Coffee cup.
+
+    An example with several shapes (including an ellipse).
+
+    Notes
+    -----
+    No copyright restrictions.  CC0 by the photographer.
+
+    """
+    return load("coffee.png")

skimage/data/tests/test_data.py

@@ -44,6 +44,11 @@ def test_chelsea():
     data.chelsea()
 
 
+def test_coffee():
+    """ Test that "coffee" image can be loaded. """
+    data.coffee()
+
+
 if __name__ == "__main__":
     from numpy.testing import run_module_suite
     run_module_suite()

skimage/transform/_hough_transform.pyx

@@ -130,9 +130,9 @@ def hough_ellipse(cnp.ndarray img, int threshold=4, double accuracy=1,
     --------
     >>> img = np.zeros((25, 25), dtype=int)
     >>> rr, cc = draw.ellipse_perimeter(10, 10, 6, 8)
-    >>> img[rr, cc] = 1
-    >>> result = hough_ellipse(img, threshold=6)
-    [(10.0, 10.0, 8.0, 6.0474292058692187, 0.0, 8)]
+    >>> img[cc, rr] = 1
+    >>> result = hough_ellipse(img, threshold=8)
+    [(10.0, 10.0, 8.0, 6.0, 0.0, 10)]
 
     Notes
     -----