Move data files to common directory.

scikits/image/__init__.py

@@ -0,0 +1,4 @@
+import os.path
+
+data_dir = os.path.join(os.path.dirname(__file__), 'tests/data')
+

scikits/image/filter/tests/test_lpi_filter.py

@@ -3,11 +3,10 @@ import os.path
 import numpy as np
 from numpy.testing import *
 
+from scikits.image import data_dir
 from scikits.image.io import *
 from scikits.image.filter import *
 
-data_dir = os.path.join(os.path.dirname(__file__), './data/')
-
 class TestLPIFilter2D():
     img = imread(os.path.join(data_dir, 'camera.png'),
                  flatten=True)[:-101,:-100]