diff --git a/bob/io/base/__init__.py b/bob/io/base/__init__.py
index ea35d2c3b70cc88a4cde18cf793f04871ddcdf1b..be46d05f4abcc186e545660ac73ca5076f35cd52 100644
--- a/bob/io/base/__init__.py
+++ b/bob/io/base/__init__.py
@@ -3,7 +3,7 @@ import numpy as np
 import h5py
 import imageio
 
-from .utils import to_bob, to_matplotlib, opencvbgr_to_bob, bob_to_opencvbgr, imshow
+from ..image import to_bob, to_matplotlib
 
 import logging
 
@@ -34,17 +34,8 @@ image_extensions = [
 
 
 def _is_string(s):
-    """Returns ``True`` if the given object is a string
-
-    This method can be used with Python-2.x or 3.x and returns a string
-    respecting each environment's constraints.
-    """
-
-    from sys import version_info
-
-    return (version_info[0] < 3 and isinstance(s, (str, unicode))) or isinstance(
-        s, (bytes, str)
-    )
+    """Returns ``True`` if the given object is a string or bytes."""
+    return isinstance(s, (bytes, str))
 
 
 @np.deprecate(new_name="os.makedirs(directory, exist_ok=True)")
diff --git a/bob/io/base/test/test_hdf5.py b/bob/io/base/test/test_hdf5.py
index 437709ff465a79c37619a004054f03b47e48b3f2..dde0a53e7cb1be00d17734265de6fbdb6b575c30 100644
--- a/bob/io/base/test/test_hdf5.py
+++ b/bob/io/base/test/test_hdf5.py
@@ -9,7 +9,7 @@
 
 import os
 from bob.io.base import load, save
-from .test_utils import temporary_filename
+from ..test_utils import temporary_filename
 
 
 import numpy as np
diff --git a/bob/io/base/test/test_image_support.py b/bob/io/base/test/test_image_support.py
index 6fe5fdd6259e3bc8cd1efc7cf376a5fb999c0f69..08989569b2876163210e5069807a2895d360a1ae 100644
--- a/bob/io/base/test/test_image_support.py
+++ b/bob/io/base/test/test_image_support.py
@@ -12,7 +12,7 @@ import os
 import numpy
 
 from bob.io.base import load, write
-from .test_utils import datafile, temporary_filename
+from ..test_utils import datafile, temporary_filename
 
 # import bob.io.image
 import nose
diff --git a/bob/io/base/test/test_io.py b/bob/io/base/test/test_io.py
index 7a31cda62c3d29180e155d192f6d82fda1c05fa1..b4ec9f684e3eda7e58b781e80f5c9e2a682e3b38 100644
--- a/bob/io/base/test/test_io.py
+++ b/bob/io/base/test/test_io.py
@@ -2,7 +2,7 @@ import nose
 import numpy as np
 import os
 from bob.io.base import vstack_features, save, load
-from .test_utils import temporary_filename
+from ..test_utils import temporary_filename
 
 
 def test_io_vstack():
diff --git a/bob/io/base/test/test_utils.py b/bob/io/base/test_utils.py
similarity index 100%
rename from bob/io/base/test/test_utils.py
rename to bob/io/base/test_utils.py
diff --git a/bob/io/base/utils.py b/bob/io/image.py
similarity index 100%
rename from bob/io/base/utils.py
rename to bob/io/image.py