Add test cases for feature utilities

skimage/feature/tests/test_util.py

@@ -1,5 +1,40 @@
 import numpy as np
-from numpy.testing import assert_array_equal
+from numpy.testing import assert_equal, assert_raises
+from skimage.feature.util import (FeatureDetector, DescriptorExtractor,
+                                  _prepare_grayscale_input_2D,
+                                  _mask_border_keypoints)
+
+
+def test_feature_detector():
+    assert_raises(NotImplementedError, FeatureDetector().detect, None)
+
+
+def test_descriptor_extractor():
+    assert_raises(NotImplementedError, DescriptorExtractor().extract,
+                  None, None)
+
+
+def test_prepare_grayscale_input_2D():
+    assert_raises(ValueError, _prepare_grayscale_input_2D, np.zeros((3, 3, 3)))
+    assert_raises(ValueError, _prepare_grayscale_input_2D, np.zeros((3, 1)))
+    assert_raises(ValueError, _prepare_grayscale_input_2D, np.zeros((3, 1, 1)))
+    img = _prepare_grayscale_input_2D(np.zeros((3, 3)))
+    img = _prepare_grayscale_input_2D(np.zeros((3, 3, 1)))
+    img = _prepare_grayscale_input_2D(np.zeros((1, 3, 3)))
+
+
+def test_mask_border_keypoints():
+    keypoints = np.array([[0, 0], [1, 1], [2, 2], [3, 3], [4, 4]])
+    assert_equal(_mask_border_keypoints((10, 10), keypoints, 0),
+                 [1, 1, 1, 1, 1])
+    assert_equal(_mask_border_keypoints((10, 10), keypoints, 2),
+                 [0, 0, 1, 1, 1])
+    assert_equal(_mask_border_keypoints((4, 4), keypoints, 2),
+                 [0, 0, 1, 0, 0])
+    assert_equal(_mask_border_keypoints((10, 10), keypoints, 5),
+                 [0, 0, 0, 0, 0])
+    assert_equal(_mask_border_keypoints((10, 10), keypoints, 4),
+                 [0, 0, 0, 0, 1])
 
 
 if __name__ == '__main__':

skimage/feature/util.py

@@ -5,9 +5,6 @@ from skimage.util import img_as_float
 
 class FeatureDetector(object):
 
-    def __init__(self):
-        raise NotImplementedError()
-
     def detect(self, image):
         """Detect keypoints in image.
 
@@ -22,9 +19,6 @@ class FeatureDetector(object):
 
 class DescriptorExtractor(object):
 
-    def __init__(self):
-        raise NotImplementedError()
-
     def extract(self, image, keypoints):
         """Extract feature descriptors in image for given keypoints.