Merge pull request #467 from malcolmreynolds/fix-num-peaks-typo

FIX: number of peaks returned from feature.corner_peaks

skimage/feature/corner.py

@@ -489,7 +489,7 @@ def corner_peaks(image, min_distance=10, threshold_abs=0, threshold_rel=0.1,
                            threshold_abs=threshold_abs,
                            threshold_rel=threshold_rel,
                            exclude_border=exclude_border,
-                           indices=False, num_peaks=np.inf,
+                           indices=False, num_peaks=num_peaks,
                            footprint=footprint, labels=labels)
     if min_distance > 0:
         coords = np.transpose(peaks.nonzero())

skimage/feature/tests/test_corner.py

@@ -100,6 +100,19 @@ def test_subpix():
     assert_array_equal(subpix[0], (24.5, 24.5))
 
 
+def test_num_peaks():
+    """For a bunch of different values of num_peaks, check that
+    peak_local_max returns exactly the right amount of peaks. Test
+    is run on Lena in order to produce a sufficient number of corners"""
+
+    lena_corners = corner_harris(data.lena())
+
+    for i in range(20):
+        n = np.random.random_integers(20)
+        results = peak_local_max(lena_corners, num_peaks=n)
+        assert (results.shape[0] == n)
+
+
 def test_corner_peaks():
     response = np.zeros((5, 5))
     response[2:4, 2:4] = 1