ENH: Add test and support for reading file URLs

skimage/io/_io.py

@@ -16,7 +16,7 @@ from skimage.color import rgb2grey
 # Shared image queue
 _image_stack = []
 
-URL_REGEX = re.compile(r'http://|https://|ftp://')
+URL_REGEX = re.compile(r'http://|https://|ftp://|file://')
 
 
 def is_url(filename):

skimage/io/tests/test_io.py

@@ -2,6 +2,7 @@ from numpy.testing import *
 import numpy as np
 
 import skimage.io as io
+from skimage import data_dir
 
 
 def test_stack_basic():
@@ -15,5 +16,12 @@ def test_stack_basic():
 def test_stack_non_array():
     io.push([[1, 2, 3]])
 
+
+def test_imread_url():
+    image_url = 'file://%s/camera.png' % data_dir
+    image = io.imread(image_url)
+    assert image.shape == (512, 512)
+
+
 if __name__ == "__main__":
     run_module_suite()