diff --git a/skimage/_shared/_warnings.py b/skimage/_shared/_warnings.py
index cf9df84a..fd2c06a0 100644
--- a/skimage/_shared/_warnings.py
+++ b/skimage/_shared/_warnings.py
@@ -1,4 +1,4 @@
-__all__ = ['all_warnings']
+__all__ = ['all_warnings', 'expected_warnings']
 
 from contextlib import contextmanager
 import sys
@@ -90,14 +90,16 @@ def expected_warnings(matching):
     """
     with all_warnings() as w:
         yield w
-        remaining = matching
+        remaining = [m for m in matching]
         for warn in w:
             found = False
             for match in matching:
                 if re.search(match, str(warn.message)) is not None:
                     found = True
-                    remaining.remove(match)
+                    if match in remaining:
+                        remaining.remove(match)
             if not found:
                 raise ValueError('Unexpected warning: %s' % str(warn.message))
         if len(remaining) > 0:
-            raise ValueError('No warning raised matching: "%s"' % remaining[0])
+            msg = 'No warning raised matching:\n%s' % '\n'.join(remaining)
+            raise ValueError(msg)
diff --git a/skimage/_shared/testing.py b/skimage/_shared/testing.py
index 6b09a7bd..e5ca2f87 100644
--- a/skimage/_shared/testing.py
+++ b/skimage/_shared/testing.py
@@ -9,7 +9,7 @@ from skimage import (
     data, io, img_as_uint, img_as_float, img_as_int, img_as_ubyte)
 from numpy import testing
 import numpy as np
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 import warnings
 
 
@@ -117,24 +117,24 @@ def color_check(plugin, fmt='png'):
     testing.assert_allclose(img2.astype(np.uint8), r2)
 
     img3 = img_as_float(img)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         r3 = roundtrip(img3, plugin, fmt)
     testing.assert_allclose(r3, img)
 
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         img4 = img_as_int(img)
     if fmt.lower() in (('tif', 'tiff')):
         img4 -= 100
-        with all_warnings():  # sign loss
+        with expected_warnings(['sign loss']):
             r4 = roundtrip(img4, plugin, fmt)
         testing.assert_allclose(r4, img4)
     else:
-        with all_warnings():  # sign loss
+        with expected_warnings(['sign loss']):
             r4 = roundtrip(img4, plugin, fmt)
             testing.assert_allclose(r4, img_as_ubyte(img4))
 
     img5 = img_as_uint(img)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         r5 = roundtrip(img5, plugin, fmt)
     testing.assert_allclose(r5, img)
 
@@ -154,22 +154,22 @@ def mono_check(plugin, fmt='png'):
     testing.assert_allclose(img2.astype(np.uint8), r2)
 
     img3 = img_as_float(img)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         r3 = roundtrip(img3, plugin, fmt)
     if r3.dtype.kind == 'f':
         testing.assert_allclose(img3, r3)
     else:
         testing.assert_allclose(r3, img_as_uint(img))
 
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         img4 = img_as_int(img)
     if fmt.lower() in (('tif', 'tiff')):
         img4 -= 100
-        with all_warnings():  # sign loss
+        with expected_warnings(['sign loss']):
             r4 = roundtrip(img4, plugin, fmt)
         testing.assert_allclose(r4, img4)
     else:
-        with all_warnings():  # sign loss
+        with expected_warnings(['sign loss']):
             r4 = roundtrip(img4, plugin, fmt)
             testing.assert_allclose(r4, img_as_uint(img4))
 
@@ -188,9 +188,7 @@ def setup_test():
     warnings.simplefilter('default')
     from scipy import signal, ndimage, special, optimize, linalg
     from scipy.io import loadmat
-    from skimage import filter, viewer, data
-    # trigger PIL warnings
-    data.moon()
+    from skimage import viewer, filter
     np.random.seed(0)
     warnings.simplefilter('error') 
 
diff --git a/skimage/_shared/tests/__init__.py b/skimage/_shared/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/_shared/tests/__init__.py
+++ b/skimage/_shared/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/color/tests/__init__.py b/skimage/color/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/color/tests/__init__.py
+++ b/skimage/color/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/color/tests/test_adapt_rgb.py b/skimage/color/tests/test_adapt_rgb.py
index f4da0e58..9e97b6b6 100644
--- a/skimage/color/tests/test_adapt_rgb.py
+++ b/skimage/color/tests/test_adapt_rgb.py
@@ -5,7 +5,7 @@ import numpy as np
 from skimage import img_as_float, img_as_uint
 from skimage import color, data, filters
 from skimage.color.adapt_rgb import adapt_rgb, each_channel, hsv_value
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 # Down-sample image for quicker testing.
 COLOR_IMAGE = data.astronaut()[::5, ::5]
@@ -38,7 +38,7 @@ def smooth_hsv(image, sigma):
 
 @adapt_rgb(hsv_value)
 def edges_hsv_uint(image):
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         return img_as_uint(filters.sobel(image))
 
 
diff --git a/skimage/color/tests/test_colorconv.py b/skimage/color/tests/test_colorconv.py
index c61a67b2..094873ae 100644
--- a/skimage/color/tests/test_colorconv.py
+++ b/skimage/color/tests/test_colorconv.py
@@ -40,12 +40,10 @@ from skimage.color import (rgb2hsv, hsv2rgb,
                            )
 
 from skimage import data_dir
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 import colorsys
 
-np.random.seed(0)
-
 
 def test_guess_spatial_dimensions():
     im1 = np.zeros((5, 5))
@@ -157,7 +155,7 @@ class TestColorconv(TestCase):
     # RGB<->HED roundtrip with ubyte image
     def test_hed_rgb_roundtrip(self):
         img_rgb = img_as_ubyte(self.img_rgb)
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             new = img_as_ubyte(hed2rgb(rgb2hed(img_rgb)))
         assert_equal(new, img_rgb)
 
diff --git a/skimage/color/tests/test_colorlabel.py b/skimage/color/tests/test_colorlabel.py
index 4daf3a66..277cec5b 100644
--- a/skimage/color/tests/test_colorlabel.py
+++ b/skimage/color/tests/test_colorlabel.py
@@ -3,7 +3,7 @@ import itertools
 import numpy as np
 from numpy import testing
 from skimage.color.colorlabel import label2rgb
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 from numpy.testing import (assert_array_almost_equal as assert_close,
                            assert_array_equal, assert_warns)
 
@@ -125,10 +125,9 @@ def test_avg():
 
 
 def test_negative_intensity():
-    with all_warnings():
-        labels = np.arange(100).reshape(10, 10)
-        image = -1 * np.ones((10, 10))
-        assert_warns(UserWarning, label2rgb, labels, image)
+    labels = np.arange(100).reshape(10, 10)
+    image = -1 * np.ones((10, 10))
+    assert_warns(UserWarning, label2rgb, labels, image)
 
 
 if __name__ == '__main__':
diff --git a/skimage/data/tests/__init__.py b/skimage/data/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/data/tests/__init__.py
+++ b/skimage/data/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/draw/tests/__init__.py b/skimage/draw/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/draw/tests/__init__.py
+++ b/skimage/draw/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/exposure/tests/__init__.py b/skimage/exposure/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/exposure/tests/__init__.py
+++ b/skimage/exposure/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/exposure/tests/test_exposure.py b/skimage/exposure/tests/test_exposure.py
index bb047195..5a3d3dba 100644
--- a/skimage/exposure/tests/test_exposure.py
+++ b/skimage/exposure/tests/test_exposure.py
@@ -11,7 +11,7 @@ from skimage import exposure
 from skimage.exposure.exposure import intensity_range
 from skimage.color import rgb2gray
 from skimage.util.dtype import dtype_range
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 # Test integer histograms
@@ -53,7 +53,7 @@ def test_equalize_uint8_approx():
 
 
 def test_equalize_ubyte():
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         img = skimage.img_as_ubyte(test_img)
     img_eq = exposure.equalize_hist(img)
 
@@ -211,7 +211,7 @@ def test_adapthist_grayscale():
     img = skimage.img_as_float(data.astronaut())
     img = rgb2gray(img)
     img = np.dstack((img, img, img))
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         adapted = exposure.equalize_adapthist(img, 10, 9, clip_limit=0.01,
                                               nbins=128)
     assert_almost_equal = np.testing.assert_almost_equal
@@ -229,7 +229,7 @@ def test_adapthist_color():
         warnings.simplefilter('always')
         hist, bin_centers = exposure.histogram(img)
         assert len(w) > 0
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         adapted = exposure.equalize_adapthist(img, clip_limit=0.01)
 
     assert_almost_equal = np.testing.assert_almost_equal
@@ -248,7 +248,7 @@ def test_adapthist_alpha():
     img = skimage.img_as_float(data.astronaut())
     alpha = np.ones((img.shape[0], img.shape[1]), dtype=float)
     img = np.dstack((img, alpha))
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         adapted = exposure.equalize_adapthist(img)
     assert adapted.shape != img.shape
     img = img[:, :, :3]
diff --git a/skimage/feature/tests/__init__.py b/skimage/feature/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/feature/tests/__init__.py
+++ b/skimage/feature/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/filters/tests/test_gaussian.py b/skimage/filters/tests/test_gaussian.py
index 01e1c12e..c88ee1f8 100644
--- a/skimage/filters/tests/test_gaussian.py
+++ b/skimage/filters/tests/test_gaussian.py
@@ -1,6 +1,6 @@
 import numpy as np
 from skimage.filters._gaussian import gaussian_filter
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def test_null_sigma():
@@ -26,7 +26,7 @@ def test_multichannel():
     assert np.allclose([a[..., i].mean() for i in range(3)],
                         [gaussian_rgb_a[..., i].mean() for i in range(3)])
     # Test multichannel = None
-    with all_warnings():  # multichannel
+    with expected_warnings(['multichannel']):
         gaussian_rgb_a = gaussian_filter(a, sigma=1, mode='reflect')
     # Check that the mean value is conserved in each channel
     # (color channels are not mixed together)
diff --git a/skimage/graph/tests/__init__.py b/skimage/graph/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/graph/tests/__init__.py
+++ b/skimage/graph/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/io/_plugins/pil_plugin.py b/skimage/io/_plugins/pil_plugin.py
index cdaea687..9f9118cf 100644
--- a/skimage/io/_plugins/pil_plugin.py
+++ b/skimage/io/_plugins/pil_plugin.py
@@ -7,7 +7,6 @@ from PIL import Image
 from skimage.util import img_as_ubyte, img_as_uint
 from skimage.external.tifffile import (
     imread as tif_imread, imsave as tif_imsave)
-from skimage._shared._warnings import expected_warnings
 
 
 def imread(fname, dtype=None, img_num=None, **kwargs):
@@ -48,8 +47,7 @@ def imread(fname, dtype=None, img_num=None, **kwargs):
     im = Image.open(fname)
     try:
         # this will raise an IOError if the file is not readable
-        with expected_warnings(['unclosed file']):
-            im.getdata()[0]
+        im.getdata()[0]
     except IOError:
         site = "http://pillow.readthedocs.org/en/latest/installation.html#external-libraries"
         raise ValueError('Could not load "%s"\nPlease see documentation at: %s' % (fname, site))
diff --git a/skimage/io/tests/__init__.py b/skimage/io/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/io/tests/__init__.py
+++ b/skimage/io/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/io/tests/test_pil.py b/skimage/io/tests/test_pil.py
index 832ea13e..2d58e3e9 100644
--- a/skimage/io/tests/test_pil.py
+++ b/skimage/io/tests/test_pil.py
@@ -10,16 +10,18 @@ from skimage import data_dir
 from skimage.io import (imread, imsave, use_plugin, reset_plugins,
                         Image as ioImage)
 from skimage._shared.testing import mono_check, color_check
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 from six import BytesIO
 
 from PIL import Image
 from skimage.io._plugins.pil_plugin import (
     pil_to_ndarray, ndarray_to_pil, _palette_is_grayscale)
-use_plugin('pil')
 
-np.random.seed(0)
+
+
+def setup():
+    use_plugin('pil')
 
 
 def teardown():
@@ -144,7 +146,7 @@ def test_imsave_filelike():
     s = BytesIO()
 
     # save to file-like object
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         imsave(s, image)
 
     # read from file-like object
@@ -157,7 +159,7 @@ def test_imsave_filelike():
 def test_imexport_imimport():
     shape = (2, 2)
     image = np.zeros(shape)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         pil_image = ndarray_to_pil(image)
     out = pil_to_ndarray(pil_image)
     assert out.shape == shape
diff --git a/skimage/io/tests/test_plugin_util.py b/skimage/io/tests/test_plugin_util.py
index 38e795f3..069622fb 100644
--- a/skimage/io/tests/test_plugin_util.py
+++ b/skimage/io/tests/test_plugin_util.py
@@ -1,5 +1,5 @@
 from skimage.io._plugins.util import prepare_for_display, WindowManager
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 from numpy.testing import *
 import numpy as np
@@ -9,16 +9,16 @@ np.random.seed(0)
 
 class TestPrepareForDisplay:
     def test_basic(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             prepare_for_display(np.random.rand(10, 10))
 
     def test_dtype(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             x = prepare_for_display(np.random.rand(10, 15))
         assert x.dtype == np.dtype(np.uint8)
 
     def test_grey(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             tmp = np.arange(12, dtype=float).reshape((4, 3)) / 11
             x = prepare_for_display(tmp)
         assert_array_equal(x[..., 0], x[..., 2])
@@ -26,21 +26,21 @@ class TestPrepareForDisplay:
         assert x[3, 2, 0] == 255
 
     def test_colour(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             prepare_for_display(np.random.rand(10, 10, 3))
 
     def test_alpha(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             prepare_for_display(np.random.rand(10, 10, 4))
 
     @raises(ValueError)
     def test_wrong_dimensionality(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             prepare_for_display(np.random.rand(10, 10, 1, 1))
 
     @raises(ValueError)
     def test_wrong_depth(self):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             prepare_for_display(np.random.rand(10, 10, 5))
 
 
diff --git a/skimage/measure/tests/__init__.py b/skimage/measure/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/measure/tests/__init__.py
+++ b/skimage/measure/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/measure/tests/test_fit.py b/skimage/measure/tests/test_fit.py
index 4305b04e..c2a71f71 100644
--- a/skimage/measure/tests/test_fit.py
+++ b/skimage/measure/tests/test_fit.py
@@ -3,7 +3,7 @@ from numpy.testing import assert_equal, assert_raises, assert_almost_equal
 from skimage.measure import LineModel, CircleModel, EllipseModel, ransac
 from skimage.transform import AffineTransform
 from skimage.measure.fit import _dynamic_max_trials
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def test_line_model_invalid_input():
@@ -256,7 +256,7 @@ def test_deprecated_params_attribute():
     model.params = (10, 1)
     x = np.arange(-10, 10)
     y = model.predict_y(x)
-    with all_warnings():  # deprecation
+    with expected_warnings(['`_params`']):
         assert_equal(model.params, model._params)
 
 
diff --git a/skimage/measure/tests/test_regionprops.py b/skimage/measure/tests/test_regionprops.py
index 830489d1..fdbabad9 100644
--- a/skimage/measure/tests/test_regionprops.py
+++ b/skimage/measure/tests/test_regionprops.py
@@ -4,7 +4,7 @@ import numpy as np
 import math
 
 from skimage.measure._regionprops import regionprops, PROPS, perimeter
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 SAMPLE = np.array(
@@ -26,16 +26,14 @@ INTENSITY_SAMPLE[1, 9:11] = 2
 def test_all_props():
     region = regionprops(SAMPLE, INTENSITY_SAMPLE)[0]
     for prop in PROPS:
-        with all_warnings():  # deprecation warning
-            assert_equal(region[prop], getattr(region, PROPS[prop]))
+        assert_equal(region[prop], getattr(region, PROPS[prop]))
 
 
 def test_dtype():
     regionprops(np.zeros((10, 10), dtype=np.int))
     regionprops(np.zeros((10, 10), dtype=np.uint))
-    with all_warnings():  # deprecation on dtype
-        assert_raises((TypeError, RuntimeError), regionprops,
-                      np.zeros((10, 10), dtype=np.double))
+    assert_raises((TypeError, RuntimeError), regionprops,
+                   np.zeros((10, 10), dtype=np.double))
 
 
 def test_ndim():
@@ -128,13 +126,13 @@ def test_equiv_diameter():
 
 
 def test_euler_number():
-    with all_warnings():  # deprecation warning
+    with expected_warnings(['`background`']):
         en = regionprops(SAMPLE)[0].euler_number
     assert en == 0
 
     SAMPLE_mod = SAMPLE.copy()
     SAMPLE_mod[7, -3] = 0
-    with all_warnings():  # deprecation warning
+    with expected_warnings(['`background`']):
         en = regionprops(SAMPLE_mod)[0].euler_number
     assert en == -1
 
@@ -374,7 +372,7 @@ def test_equals():
     r2 = regions[0]
     r3 = regions[1]
 
-    with all_warnings():  # deprecation warning
+    with expected_warnings(['`background`']):
         assert_equal(r1 == r2, True, "Same regionprops are not equal")
         assert_equal(r1 != r3, True, "Different regionprops are equal")
 
diff --git a/skimage/morphology/tests/__init__.py b/skimage/morphology/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/morphology/tests/__init__.py
+++ b/skimage/morphology/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/morphology/tests/test_binary.py b/skimage/morphology/tests/test_binary.py
index 3a3abf97..d52f92bb 100644
--- a/skimage/morphology/tests/test_binary.py
+++ b/skimage/morphology/tests/test_binary.py
@@ -4,7 +4,7 @@ from numpy import testing
 from skimage import data, color
 from skimage.util import img_as_bool
 from skimage.morphology import binary, grey, selem
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 from scipy import ndimage
 
 
@@ -15,7 +15,7 @@ bw_img = img > 100
 def test_non_square_image():
     strel = selem.square(3)
     binary_res = binary.binary_erosion(bw_img[:100, :200], strel)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         grey_res = img_as_bool(grey.erosion(bw_img[:100, :200], strel))
     testing.assert_array_equal(binary_res, grey_res)
 
@@ -23,7 +23,7 @@ def test_non_square_image():
 def test_binary_erosion():
     strel = selem.square(3)
     binary_res = binary.binary_erosion(bw_img, strel)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         grey_res = img_as_bool(grey.erosion(bw_img, strel))
     testing.assert_array_equal(binary_res, grey_res)
 
@@ -31,7 +31,7 @@ def test_binary_erosion():
 def test_binary_dilation():
     strel = selem.square(3)
     binary_res = binary.binary_dilation(bw_img, strel)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         grey_res = img_as_bool(grey.dilation(bw_img, strel))
     testing.assert_array_equal(binary_res, grey_res)
 
@@ -39,7 +39,7 @@ def test_binary_dilation():
 def test_binary_closing():
     strel = selem.square(3)
     binary_res = binary.binary_closing(bw_img, strel)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         grey_res = img_as_bool(grey.closing(bw_img, strel))
     testing.assert_array_equal(binary_res, grey_res)
 
@@ -47,7 +47,7 @@ def test_binary_closing():
 def test_binary_opening():
     strel = selem.square(3)
     binary_res = binary.binary_opening(bw_img, strel)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         grey_res = img_as_bool(grey.opening(bw_img, strel))
     testing.assert_array_equal(binary_res, grey_res)
 
@@ -57,7 +57,7 @@ def test_selem_overflow():
     img = np.zeros((20, 20))
     img[2:19, 2:19] = 1
     binary_res = binary.binary_erosion(img, strel)
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         grey_res = img_as_bool(grey.erosion(img, strel))
     testing.assert_array_equal(binary_res, grey_res)
 
diff --git a/skimage/morphology/tests/test_ccomp.py b/skimage/morphology/tests/test_ccomp.py
index 569b0e38..901a18b9 100644
--- a/skimage/morphology/tests/test_ccomp.py
+++ b/skimage/morphology/tests/test_ccomp.py
@@ -1,22 +1,16 @@
 import numpy as np
 from numpy.testing import assert_array_equal, run_module_suite
 
-from skimage.morphology import label as _label
+from skimage.measure import label
 import skimage.measure._ccomp as ccomp
-from skimage._shared.utils import all_warnings
-np.random.seed(0)
+from skimage._shared._warnings import expected_warnings
+
 
 # The background label value
 # is supposed to be changed to 0 soon
 BG = -1
 
 
-def label(*args, **kwargs):
-    """Wrap the label function to avoid deprecation warning"""
-    with all_warnings():
-        return _label(*args, **kwargs)
-
-
 class TestConnectedComponents:
     def setup(self):
         self.x = np.array([[0, 0, 3, 2, 1, 9],
@@ -30,7 +24,8 @@ class TestConnectedComponents:
                                 [6, 5, 5, 7, 8, 9]])
 
     def test_basic(self):
-        assert_array_equal(label(self.x), self.labels)
+        with expected_warnings(['`background`']):
+            assert_array_equal(label(self.x), self.labels)
 
         # Make sure data wasn't modified
         assert self.x[0, 2] == 3
@@ -38,7 +33,7 @@ class TestConnectedComponents:
     def test_random(self):
         x = (np.random.rand(20, 30) * 5).astype(np.int)
 
-        with all_warnings():
+        with expected_warnings(['`background`']):
             labels = label(x)
 
         n = labels.max()
@@ -50,13 +45,13 @@ class TestConnectedComponents:
         x = np.array([[0, 0, 1],
                       [0, 1, 0],
                       [1, 0, 0]])
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x), x)
 
     def test_4_vs_8(self):
         x = np.array([[0, 1],
                       [1, 0]], dtype=int)
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x, 4),
                                [[0, 1],
                                 [2, 3]])
@@ -69,7 +64,7 @@ class TestConnectedComponents:
                       [1, 1, 5],
                       [0, 0, 0]])
 
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x), [[0, 1, 1],
                                           [0, 0, 2],
                                           [3, 3, 3]])
@@ -105,7 +100,7 @@ class TestConnectedComponents:
                       [0, 0, 6],
                       [5, 5, 5]])
 
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x, return_num=True)[1], 4)
 
         assert_array_equal(label(x, background=0, return_num=True)[1], 3)
@@ -147,7 +142,8 @@ class TestConnectedComponents3d:
                                    [10, 5, 7, 7, 7]])
 
     def test_basic(self):
-        labels = label(self.x)
+        with expected_warnings(['`background`']):
+            labels = label(self.x)
         assert_array_equal(labels, self.labels)
 
         assert self.x[0, 0, 2] == 2, \
@@ -156,7 +152,7 @@ class TestConnectedComponents3d:
     def test_random(self):
         x = (np.random.rand(20, 30) * 5).astype(np.int)
 
-        with all_warnings():
+        with expected_warnings(['`background`']):
             labels = label(x)
 
         n = labels.max()
@@ -169,7 +165,7 @@ class TestConnectedComponents3d:
         x[0, 2, 2] = 1
         x[1, 1, 1] = 1
         x[2, 0, 0] = 1
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x), x)
 
     def test_4_vs_8(self):
@@ -178,7 +174,7 @@ class TestConnectedComponents3d:
         x[1, 0, 0] = 1
         label4 = x.copy()
         label4[1, 0, 0] = 2
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x, 4), label4)
             assert_array_equal(label(x, 8), x)
 
@@ -206,7 +202,7 @@ class TestConnectedComponents3d:
                           [BG, 0,   1],
                           [BG, BG, BG]])
 
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x), lnb)
 
         assert_array_equal(label(x, background=0), lb)
@@ -244,7 +240,7 @@ class TestConnectedComponents3d:
                       [0, 0, 6],
                       [5, 5, 5]])
 
-        with all_warnings():
+        with expected_warnings(['`background`']):
             assert_array_equal(label(x, return_num=True)[1], 4)
 
         assert_array_equal(label(x, background=0, return_num=True)[1], 3)
@@ -258,7 +254,8 @@ class TestConnectedComponents3d:
                     (1, xlen, 1), (xlen, 1, 1), (1, 1, xlen))
         for reshape in reshapes:
             x2 = x.reshape(reshape)
-            labelled = label(x2)
+            with expected_warnings(['`background`']):
+                labelled = label(x2)
             assert_array_equal(y, labelled.flatten())
 
     def test_nd(self):
diff --git a/skimage/morphology/tests/test_grey.py b/skimage/morphology/tests/test_grey.py
index 9c978105..9961b985 100644
--- a/skimage/morphology/tests/test_grey.py
+++ b/skimage/morphology/tests/test_grey.py
@@ -7,7 +7,7 @@ from scipy import ndimage
 import skimage
 from skimage import data_dir
 from skimage.morphology import grey, selem
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 lena = np.load(os.path.join(data_dir, 'lena_GRAY_U8.npy'))
@@ -172,10 +172,10 @@ def test_3d_fallback_white_tophat():
     image[3, 2:5, 2:5] = 1
     image[4, 3:5, 3:5] = 1
 
-    with all_warnings():  # scipy upstream warning
+    with expected_warnings(['operator.*deprecated']):
         new_image = grey.white_tophat(image)
     footprint = ndimage.generate_binary_structure(3,1)
-    with all_warnings():  # scipy upstream warning
+    with expected_warnings(['operator.*deprecated']):
         image_expected = ndimage.white_tophat(image,footprint=footprint)
     testing.assert_array_equal(new_image, image_expected)
 
@@ -185,10 +185,10 @@ def test_3d_fallback_black_tophat():
     image[3, 2:5, 2:5] = 0
     image[4, 3:5, 3:5] = 0
 
-    with all_warnings():  # scipy upstream warning
+    with expected_warnings(['operator.*deprecated']):
         new_image = grey.black_tophat(image)
     footprint = ndimage.generate_binary_structure(3,1)
-    with all_warnings():  # scipy upstream warning
+    with expected_warnings(['operator.*deprecated']):
         image_expected = ndimage.black_tophat(image,footprint=footprint)
     testing.assert_array_equal(new_image, image_expected)
 
@@ -223,11 +223,11 @@ class TestDTypes():
         self.expected_closing = np.load(fname_closing)[arrname]
 
     def _test_image(self, image):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             result_opening = grey.opening(image, self.disk)
         testing.assert_equal(result_opening, self.expected_opening)
 
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             result_closing = grey.closing(image, self.disk)
         testing.assert_equal(result_closing, self.expected_closing)
 
diff --git a/skimage/restoration/tests/__init__.py b/skimage/restoration/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/restoration/tests/__init__.py
+++ b/skimage/restoration/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/restoration/tests/test_unwrap.py b/skimage/restoration/tests/test_unwrap.py
index 4819ea24..e628f4fe 100644
--- a/skimage/restoration/tests/test_unwrap.py
+++ b/skimage/restoration/tests/test_unwrap.py
@@ -7,7 +7,7 @@ from numpy.testing import (run_module_suite, assert_array_almost_equal_nulp,
 import warnings
 
 from skimage.restoration import unwrap_phase
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def assert_phase_almost_equal(a, b, *args, **kwargs):
@@ -133,7 +133,7 @@ def test_mask():
         assert_array_almost_equal_nulp(image_unwrapped[:, -1], image[i, -1])
 
         # Same tests, but forcing use of the 3D unwrapper by reshaping
-        with all_warnings():  # 1 dimension
+        with expected_warnings(['length 1 dimension']):
             shape = (1,) + image_wrapped.shape
             image_wrapped_3d = image_wrapped.reshape(shape)
             image_unwrapped_3d = unwrap_phase(image_wrapped_3d)
diff --git a/skimage/segmentation/tests/__init__.py b/skimage/segmentation/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/segmentation/tests/__init__.py
+++ b/skimage/segmentation/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/segmentation/tests/test_random_walker.py b/skimage/segmentation/tests/test_random_walker.py
index ed68cb0f..5877a817 100644
--- a/skimage/segmentation/tests/test_random_walker.py
+++ b/skimage/segmentation/tests/test_random_walker.py
@@ -1,7 +1,14 @@
 import numpy as np
 from skimage.segmentation import random_walker
 from skimage.transform import resize
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
+from skimage._shared.version_requirements import is_installed
+
+
+if is_installed('pyamg'):
+    PYAMG_EXPECTED_WARNING = []
+else:
+    PYAMG_EXPECTED_WARNING = ['pyamg']
 
 
 def make_2d_syntheticdata(lx, ly=None):
@@ -75,11 +82,11 @@ def test_2d_cg():
     lx = 70
     ly = 100
     data, labels = make_2d_syntheticdata(lx, ly)
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         labels_cg = random_walker(data, labels, beta=90, mode='cg')
     assert (labels_cg[25:45, 40:60] == 2).all()
     assert data.shape == labels.shape
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         full_prob = random_walker(data, labels, beta=90, mode='cg',
                                   return_full_prob=True)
     assert (full_prob[1, 25:45, 40:60] >=
@@ -92,11 +99,11 @@ def test_2d_cg_mg():
     lx = 70
     ly = 100
     data, labels = make_2d_syntheticdata(lx, ly)
-    with all_warnings():  # pyamg optional
+    with expected_warnings(PYAMG_EXPECTED_WARNING):
         labels_cg_mg = random_walker(data, labels, beta=90, mode='cg_mg')
     assert (labels_cg_mg[25:45, 40:60] == 2).all()
     assert data.shape == labels.shape
-    with all_warnings():  # pyamg optional
+    with expected_warnings(PYAMG_EXPECTED_WARNING):
         full_prob = random_walker(data, labels, beta=90, mode='cg_mg',
                               return_full_prob=True)
     assert (full_prob[1, 25:45, 40:60] >=
@@ -111,7 +118,7 @@ def test_types():
     data, labels = make_2d_syntheticdata(lx, ly)
     data = 255 * (data - data.min()) // (data.max() - data.min())
     data = data.astype(np.uint8)
-    with all_warnings():  # pyamg optional
+    with expected_warnings(PYAMG_EXPECTED_WARNING):
         labels_cg_mg = random_walker(data, labels, beta=90, mode='cg_mg')
     assert (labels_cg_mg[25:45, 40:60] == 2).all()
     assert data.shape == labels.shape
@@ -145,7 +152,7 @@ def test_3d():
     n = 30
     lx, ly, lz = n, n, n
     data, labels = make_3d_syntheticdata(lx, ly, lz)
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         labels = random_walker(data, labels, mode='cg')
     assert (labels.reshape(data.shape)[13:17, 13:17, 13:17] == 2).all()
     assert data.shape == labels.shape
@@ -159,7 +166,7 @@ def test_3d_inactive():
     old_labels = np.copy(labels)
     labels[5:25, 26:29, 26:29] = -1
     after_labels = np.copy(labels)
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         labels = random_walker(data, labels, mode='cg')
     assert (labels.reshape(data.shape)[13:17, 13:17, 13:17] == 2).all()
     assert data.shape == labels.shape
@@ -170,11 +177,11 @@ def test_multispectral_2d():
     lx, ly = 70, 100
     data, labels = make_2d_syntheticdata(lx, ly)
     data = data[..., np.newaxis].repeat(2, axis=-1)  # Expect identical output
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         multi_labels = random_walker(data, labels, mode='cg',
                                      multichannel=True)
     assert data[..., 0].shape == labels.shape
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         single_labels = random_walker(data[..., 0], labels, mode='cg')
     assert (multi_labels.reshape(labels.shape)[25:45, 40:60] == 2).all()
     assert data[..., 0].shape == labels.shape
@@ -186,11 +193,11 @@ def test_multispectral_3d():
     lx, ly, lz = n, n, n
     data, labels = make_3d_syntheticdata(lx, ly, lz)
     data = data[..., np.newaxis].repeat(2, axis=-1)  # Expect identical output
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         multi_labels = random_walker(data, labels, mode='cg', 
                                      multichannel=True)
     assert data[..., 0].shape == labels.shape
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         single_labels = random_walker(data[..., 0], labels, mode='cg')
     assert (multi_labels.reshape(labels.shape)[13:17, 13:17, 13:17] == 2).all()
     assert (single_labels.reshape(labels.shape)[13:17, 13:17, 13:17] == 2).all()
@@ -217,7 +224,7 @@ def test_spacing_0():
                  lz // 4 - small_l // 8] = 2
 
     # Test with `spacing` kwarg
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         labels_aniso = random_walker(data_aniso, labels_aniso, mode='cg',
                                  spacing=(1., 1., 0.5))
 
@@ -245,7 +252,7 @@ def test_spacing_1():
 
     # Test with `spacing` kwarg
     # First, anisotropic along Y
-    with all_warnings():  # using cg mode
+    with expected_warnings(['"cg" mode']):
         labels_aniso = random_walker(data_aniso, labels_aniso, mode='cg',
                                      spacing=(1., 2., 1.))
     assert (labels_aniso[13:17, 26:34, 13:17] == 2).all()
@@ -265,7 +272,7 @@ def test_spacing_1():
                   lz // 2 - small_l // 4] = 2
 
     # Anisotropic along X
-    with all_warnings():  # cg mode
+    with expected_warnings(['"cg" mode']):
         labels_aniso2 = random_walker(data_aniso,
                                       labels_aniso2,
                                       mode='cg', spacing=(2., 1., 1.))
@@ -277,7 +284,7 @@ def test_trivial_cases():
     img = np.ones((10, 10))
     labels = np.ones((10, 10))
 
-    with all_warnings():  # using provided labels
+    with expected_warnings(["Returning provided labels"]):
         pass_through = random_walker(img, labels)
     np.testing.assert_array_equal(pass_through, labels)
 
@@ -285,7 +292,7 @@ def test_trivial_cases():
     labels[:, :5] = 3
     expected = np.concatenate(((labels == 1)[..., np.newaxis],
                                (labels == 3)[..., np.newaxis]), axis=2)
-    with all_warnings():  # using provided labels
+    with expected_warnings(["Returning provided labels"]):
         test = random_walker(img, labels, return_full_prob=True)
     np.testing.assert_array_equal(test, expected)
 
diff --git a/skimage/transform/tests/__init__.py b/skimage/transform/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/transform/tests/__init__.py
+++ b/skimage/transform/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/transform/tests/test_geometric.py b/skimage/transform/tests/test_geometric.py
index b6e0597f..125faf6c 100644
--- a/skimage/transform/tests/test_geometric.py
+++ b/skimage/transform/tests/test_geometric.py
@@ -7,7 +7,7 @@ from skimage.transform import (estimate_transform, matrix_transform,
                                SimilarityTransform, AffineTransform,
                                ProjectiveTransform, PolynomialTransform,
                                PiecewiseAffineTransform)
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 SRC = np.array([
@@ -252,11 +252,11 @@ def test_invalid_input():
 def test_deprecated_params_attributes():
     for t in ('projective', 'affine', 'similarity'):
         tform = estimate_transform(t, SRC, DST)
-        with all_warnings():  # _matrix is deprecated
+        with expected_warnings(['`_matrix`.*deprecated']):
             assert_equal(tform._matrix, tform.params)
 
     tform = estimate_transform('polynomial', SRC, DST, order=3)
-    with all_warnings():  # _params is deprecated
+    with expected_warnings(['`_params`.*deprecated']):
         assert_equal(tform._params, tform.params)
 
 
diff --git a/skimage/transform/tests/test_hough_transform.py b/skimage/transform/tests/test_hough_transform.py
index ae6e0cf6..884d7957 100644
--- a/skimage/transform/tests/test_hough_transform.py
+++ b/skimage/transform/tests/test_hough_transform.py
@@ -3,7 +3,7 @@ from numpy.testing import assert_almost_equal, assert_equal
 
 import skimage.transform as tf
 from skimage.draw import line, circle_perimeter, ellipse_perimeter
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def append_desc(func, description):
@@ -68,7 +68,7 @@ def test_hough_line_peaks():
 
     out, angles, d = tf.hough_line(img)
 
-    with all_warnings():  # _ccomp deprecation
+    with expected_warnings(['`background`']):
         out, theta, dist = tf.hough_line_peaks(out, angles, d)
 
     assert_equal(len(dist), 1)
@@ -81,7 +81,7 @@ def test_hough_line_peaks_dist():
     img[:, 30] = True
     img[:, 40] = True
     hspace, angles, dists = tf.hough_line(img)
-    with all_warnings():  # _ccomp deprecation
+    with expected_warnings(['`background`']):
         assert len(tf.hough_line_peaks(hspace, angles, dists,
                                        min_distance=5)[0]) == 2
         assert len(tf.hough_line_peaks(hspace, angles, dists,
@@ -89,7 +89,7 @@ def test_hough_line_peaks_dist():
 
 
 def test_hough_line_peaks_angle():
-    with all_warnings():  # _ccomp deprecation
+    with expected_warnings(['`background`']):
         check_hough_line_peaks_angle()
 
 
@@ -124,7 +124,7 @@ def test_hough_line_peaks_num():
     img[:, 30] = True
     img[:, 40] = True
     hspace, angles, dists = tf.hough_line(img)
-    with all_warnings():  # _ccomp deprecation
+    with expected_warnings(['`background`']):
         assert len(tf.hough_line_peaks(hspace, angles, dists, min_distance=0,
                                        min_angle=0, num_peaks=1)[0]) == 1
 
diff --git a/skimage/transform/tests/test_warps.py b/skimage/transform/tests/test_warps.py
index b0c58281..115f0e6f 100644
--- a/skimage/transform/tests/test_warps.py
+++ b/skimage/transform/tests/test_warps.py
@@ -10,7 +10,7 @@ from skimage.transform import (warp, warp_coords, rotate, resize, rescale,
                                downscale_local_mean)
 from skimage import transform as tf, data, img_as_float
 from skimage.color import rgb2gray
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 np.random.seed(0)
@@ -198,7 +198,7 @@ def test_swirl():
 
     swirl_params = {'radius': 80, 'rotation': 0, 'order': 2, 'mode': 'reflect'}
     
-    with all_warnings():  # deprecation warning
+    with expected_warnings(['Bi-quadratic.*bug']):
         swirled = tf.swirl(image, strength=10, **swirl_params)
         unswirled = tf.swirl(swirled, strength=-10, **swirl_params)
 
diff --git a/skimage/util/tests/__init__.py b/skimage/util/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/util/tests/__init__.py
+++ b/skimage/util/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/util/tests/test_dtype.py b/skimage/util/tests/test_dtype.py
index 50ad3fc4..4c1f2a43 100644
--- a/skimage/util/tests/test_dtype.py
+++ b/skimage/util/tests/test_dtype.py
@@ -3,7 +3,7 @@ from numpy.testing import assert_equal, assert_raises
 from skimage import img_as_int, img_as_float, \
                     img_as_uint, img_as_ubyte
 from skimage.util.dtype import convert
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 dtype_range = {np.uint8: (0, 255),
@@ -29,9 +29,13 @@ def test_range():
                         (img_as_float, np.float64),
                         (img_as_uint, np.uint16),
                         (img_as_ubyte, np.ubyte)]:
-
-            with all_warnings():  # precision loss
-              y = f(x)
+            
+            try:
+                with expected_warnings(['precision loss|sign loss']):
+                    y = f(x)
+            except ValueError as e:
+                if not 'No warning raised' in str(e):
+                    raise
 
             omin, omax = dtype_range[dt]
 
@@ -62,8 +66,14 @@ def test_range_extra_dtypes():
     for dtype_in, dt in dtype_pairs:
         imin, imax = dtype_range_extra[dtype_in]
         x = np.linspace(imin, imax, 10).astype(dtype_in)
-        with all_warnings():  # sign loss
-          y = convert(x, dt)
+        
+        try:
+            with expected_warnings(['precision loss|sign loss']):
+                y = convert(x, dt)
+        except ValueError as e:
+          if not 'No warning raised' in str(e):
+            raise
+
         omin, omax = dtype_range_extra[dt]
         yield (_verify_range,
                "From %s to %s" % (np.dtype(dtype_in), np.dtype(dt)),
diff --git a/skimage/util/tests/test_shape.py b/skimage/util/tests/test_shape.py
index ee897e7c..38127df8 100644
--- a/skimage/util/tests/test_shape.py
+++ b/skimage/util/tests/test_shape.py
@@ -3,7 +3,7 @@ from nose.tools import raises
 from numpy.testing import assert_equal, assert_warns
 
 from skimage.util.shape import view_as_blocks, view_as_windows
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 @raises(TypeError)
@@ -153,9 +153,8 @@ def test_views_non_contiguous():
     A = np.arange(16).reshape((4, 4))
     A = A[::2, :]
 
-    with all_warnings():
-        assert_warns(RuntimeWarning, view_as_blocks, A, (2, 2))
-        assert_warns(RuntimeWarning, view_as_windows, A, (2, 2))
+    assert_warns(RuntimeWarning, view_as_blocks, A, (2, 2))
+    assert_warns(RuntimeWarning, view_as_windows, A, (2, 2))
 
 
 if __name__ == '__main__':
diff --git a/skimage/viewer/tests/__init__.py b/skimage/viewer/tests/__init__.py
index c098c64d..9c11267a 100644
--- a/skimage/viewer/tests/__init__.py
+++ b/skimage/viewer/tests/__init__.py
@@ -1,2 +1,9 @@
-from skimage._shared.testing import setup_test
-setup_test()
+from skimage._shared.testing import setup_test, teardown_test
+
+
+def setup():
+    setup_test()
+
+
+def tearDown():
+    teardown_test()
diff --git a/skimage/viewer/tests/test_plugins.py b/skimage/viewer/tests/test_plugins.py
index 6ad180fb..528df8f4 100644
--- a/skimage/viewer/tests/test_plugins.py
+++ b/skimage/viewer/tests/test_plugins.py
@@ -12,7 +12,7 @@ from skimage.viewer.plugins import (
     PlotPlugin)
 from skimage.viewer.plugins.base import Plugin
 from skimage.viewer.widgets import Slider
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def setup_line_profile(image, limits='image'):
@@ -67,7 +67,7 @@ def test_line_profile_dynamic():
     assert_almost_equal(np.std(line), 0.229, 3)
     assert_almost_equal(np.max(line) - np.min(line), 0.725, 1)
 
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         viewer.image = skimage.img_as_float(median(image,
                                                    selem=disk(radius=3)))
 
@@ -161,7 +161,7 @@ def test_plugin():
     viewer = ImageViewer(img)
 
     def median_filter(img, radius=3):
-        with all_warnings():  # precision loss
+        with expected_warnings(['precision loss']):
             return median(img, selem=disk(radius=radius))
 
     plugin = Plugin(image_filter=median_filter)
diff --git a/skimage/viewer/tests/test_viewer.py b/skimage/viewer/tests/test_viewer.py
index 553a8be3..1604ca6d 100644
--- a/skimage/viewer/tests/test_viewer.py
+++ b/skimage/viewer/tests/test_viewer.py
@@ -8,7 +8,7 @@ from skimage.filters import sobel
 from numpy.testing import assert_equal
 from numpy.testing.decorators import skipif
 from skimage._shared.version_requirements import is_installed
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 @skipif(not viewer_available)
@@ -68,7 +68,7 @@ def test_viewer_with_overlay():
     ov.color = 3
     assert_equal(ov.color, 'yellow')
 
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         viewer.save_to_file(filename)
     ov.display_filtered_image(img)
     assert_equal(ov.overlay, img)
diff --git a/skimage/viewer/tests/test_widgets.py b/skimage/viewer/tests/test_widgets.py
index 439454f3..170c186c 100644
--- a/skimage/viewer/tests/test_widgets.py
+++ b/skimage/viewer/tests/test_widgets.py
@@ -8,7 +8,7 @@ from skimage.viewer.plugins.base import Plugin
 from skimage.viewer.qt import QtGui, QtCore
 from numpy.testing import assert_almost_equal, assert_equal
 from numpy.testing.decorators import skipif
-from skimage._shared.utils import all_warnings
+from skimage._shared._warnings import expected_warnings
 
 
 def get_image_viewer():
@@ -100,12 +100,12 @@ def test_save_buttons():
     timer.singleShot(100, QtGui.QApplication.quit)
 
     sv.save_to_stack()
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         sv.save_to_file(filename)
 
     img = data.imread(filename)
 
-    with all_warnings():  # precision loss
+    with expected_warnings(['precision loss']):
         assert_almost_equal(img, img_as_uint(viewer.image))
 
     img = io.pop()