Merge pull request #2196 from sciunto/horse

Add missing unittests for data and convert horse to binary

doc/source/user_guide/transforming_image_data.rst

@@ -50,7 +50,7 @@ background is realized with :func:`rgba2rgb` ::
 
     >>> from skimage.color import rgba2rgb
     >>> from skimage import data
-    >>> img_rgba = data.horse()
+    >>> img_rgba = data.logo()
     >>> img_rgb = rgba2rgb(img_rgba)
 
 Conversion between color and gray values

skimage/_shared/_warnings.py

@@ -82,7 +82,6 @@ def expected_warnings(matching):
     matching : list of strings or compiled regexes
         Regexes for the desired warning to catch
 
-
     Examples
     --------
     >>> from skimage import data, img_as_ubyte, img_as_float
@@ -96,14 +95,14 @@ def expected_warnings(matching):
     pattern(s).
     Raises a ValueError if any match was not found or an unexpected
     warning was raised.
-    Allows for three types of behaviors: "and", "or", and "optional" matches.
+    Allows for three types of behaviors: `and`, `or`, and `optional` matches.
     This is done to accomodate different build enviroments or loop conditions
     that may produce different warnings.  The behaviors can be combined.
-    If you pass multiple patterns, you get an orderless "and", where all of the
+    If you pass multiple patterns, you get an orderless `and`, where all of the
     warnings must be raised.
-    If you use the "|" operator in a pattern, you can catch one of several
+    If you use the `|` operator in a pattern, you can catch one of several
     warnings.
-    Finally, you can use "|\A\Z" in a pattern to signify it as optional.
+    Finally, you can use `|\A\Z` in a pattern to signify it as optional.
 
     """
     with all_warnings() as w:

skimage/color/colorconv.py

@@ -200,7 +200,7 @@ def rgba2rgb(rgba, background=(1, 1, 1)):
     --------
     >>> from skimage import color
     >>> from skimage import data
-    >>> img_rgba = data.horse()
+    >>> img_rgba = data.logo()
     >>> img_rgb = color.rgba2rgb(img_rgba)
     """
     arr = _prepare_rgba_array(rgba)

skimage/data/__init__.py

@@ -10,34 +10,37 @@ import os as _os
 
 from .. import data_dir
 from ..io import imread, use_plugin
-from .._shared.utils import deprecated
+from .._shared._warnings import expected_warnings
 from ._binary_blobs import binary_blobs
+from .. import img_as_bool
 
 __all__ = ['load',
+           'astronaut',
            'camera',
-           'lena',
-           'text',
            'checkerboard',
+           'chelsea',
+           'clock',
+           'coffee',
            'coins',
+           'horse',
+           'hubble_deep_field',
+           'immunohistochemistry',
+           'logo',
            'moon',
            'page',
-           'horse',
-           'clock',
-           'immunohistochemistry',
-           'chelsea',
-           'coffee',
-           'hubble_deep_field',
-           'rocket',
-           'astronaut']
+           'text',
+           'rocket']
 
 
-def load(f):
+def load(f, as_grey=False):
     """Load an image file located in the data directory.
 
     Parameters
     ----------
     f : string
         File name.
+    as_grey : bool, optional
+        Convert to greyscale.
 
     Returns
     -------
@@ -45,7 +48,7 @@ def load(f):
         Image loaded from ``skimage.data_dir``.
     """
     use_plugin('pil')
-    return imread(_os.path.join(data_dir, f))
+    return imread(_os.path.join(data_dir, f), as_grey=as_grey)
 
 
 def camera():
@@ -57,22 +60,6 @@ def camera():
     return load("camera.png")
 
 
-@deprecated('skimage.data.astronaut')
-def lena():
-    """Colour "Lena" image.
-
-    **This image has been removed from scikit-image due to copyright
-    concerns.**
-
-    The standard, yet sometimes controversial Lena test image was
-    scanned from the November 1972 edition of Playboy magazine.  From
-    an image processing perspective, this image is useful because it
-    contains smooth, textured, shaded as well as detail areas.
-
-    """
-    raise RuntimeError("This image has been removed due to copyright concerns.")
-
-
 def astronaut():
     """Colour image of the astronaut Eileen Collins.
 
@@ -138,6 +125,11 @@ def coins():
     return load("coins.png")
 
 
+def logo():
+    """Scikit-image logo, a RGBA image."""
+    return load("logo.png")
+
+
 def moon():
     """Surface of the moon.
 
@@ -168,7 +160,8 @@ def horse():
     (marauder).
 
     """
-    return load("horse.png")
+    with expected_warnings(['Possible precision loss', 'Possible sign loss']):
+        return img_as_bool(load("horse.png", as_grey=True))
 
 
 def clock():
@@ -242,8 +235,8 @@ def hubble_deep_field():
     `HubbleSite
     <http://hubblesite.org/newscenter/archive/releases/2012/37/image/a/>`__.
 
-    The image was captured by NASA and `may be freely used in the
-    public domain <http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html>`_.
+    The image was captured by NASA and `may be freely used in the public domain
+    <http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html>`_.
 
     """
     return load("hubble_deep_field.jpg")

skimage/data/tests/test_data.py

@@ -3,11 +3,6 @@ import skimage.data as data
 from numpy.testing import assert_equal, assert_almost_equal, assert_raises
 
 
-def test_lena_removed():
-    """ Test that "Lena" has been removed """
-    assert_raises(RuntimeError, data.lena)
-
-
 def test_astronaut():
     """ Test that "astronaut" image can be loaded. """
     astronaut = data.astronaut()
@@ -25,9 +20,43 @@ def test_checkerboard():
     data.checkerboard()
 
 
-def test_text():
-    """ Test that "text" image can be loaded. """
-    data.text()
+def test_chelsea():
+    """ Test that "chelsea" image can be loaded. """
+    data.chelsea()
+
+
+def test_clock():
+    """ Test that "clock" image can be loaded. """
+    data.clock()
+
+
+def test_coffee():
+    """ Test that "coffee" image can be loaded. """
+    data.coffee()
+
+
+def test_horse():
+    """ Test that "horse" image can be loaded. """
+    horse = data.horse()
+    assert_equal(horse.ndim, 2)
+    assert_equal(horse.dtype, np.dtype('bool'))
+
+
+def test_hubble():
+    """ Test that "Hubble" image can be loaded. """
+    data.hubble_deep_field()
+
+
+def test_immunohistochemistry():
+    """ Test that "immunohistochemistry" image can be loaded. """
+    data.immunohistochemistry()
+
+
+def test_logo():
+    """ Test that "logo" image can be loaded. """
+    logo = data.logo()
+    assert_equal(logo.ndim, 3)
+    assert_equal(logo.shape[2], 4)
 
 
 def test_moon():
@@ -40,19 +69,14 @@ def test_page():
     data.page()
 
 
-def test_clock():
-    """ Test that "clock" image can be loaded. """
-    data.clock()
+def test_rocket():
+    """ Test that "rocket" image can be loaded. """
+    data.rocket()
 
 
-def test_chelsea():
-    """ Test that "chelsea" image can be loaded. """
-    data.chelsea()
-
-
-def test_coffee():
-    """ Test that "coffee" image can be loaded. """
-    data.coffee()
+def test_text():
+    """ Test that "text" image can be loaded. """
+    data.text()
 
 
 def test_binary_blobs():