Allow unit tests to be run when OpenCV is not available.

scikits/image/opencv/__init__.py

@@ -1,22 +1,15 @@
 import ctypes
-
-# try to open the opencv libs
-# raise an exception if the libs are not found
-
-# linux
-try:
-    ctypes.CDLL('libcv.so')    
-except:
-    # windows
-    try:
-        ctypes.CDLL('cv.dll')
-    except:        
-        raise RuntimeError('The opencv libraries were not found. Please make sure they are installed and available on the system path.')
+import warnings
 
 from opencv_constants import *
-from opencv_cv import *
 
-#def test(level=1, verbosity=1):
-#    from numpy.testing import Tester
-#    return Tester().test(level, verbosity)
+libs_found = True
 
+try:
+    from opencv_cv import *
+except:
+    warnings.warn(RuntimeWarning(
+        'The opencv libraries were not found.  Please ensure that they '
+        'are installed and available on the system path. '
+        '*** Skipping import of OpenCV functions.'))
+    libs_found = False

scikits/image/opencv/opencv_cv.pyx

@@ -11,14 +11,8 @@ from opencv_constants import *
 #one of these should work if the user imported the package properly
 try:
     cv = ctypes.CDLL('libcv.so')
-except:
-    try:
-        cv = ctypes.CDLL('cv.dll')
-    except:
-        raise RuntimeError('The opencv libraries were not found. '
-                           'Please make sure they are installed and '
-                           'available on the system path.')
-
+except OSError:
+    cv = ctypes.CDLL('cv.dll')
 
 ###################################
 # opencv function declarations

scikits/image/opencv/tests/test_opencv_cv.py

@@ -1,77 +1,74 @@
 # test for the opencv_cv extension module
 import os
+import warnings
+
 import numpy as np
 from numpy.testing import *
 
-try:
-    from scikits.image.opencv import *
-    OPENCV_LIBS_NOTFOUND = False
-except:
-    OPENCV_LIBS_NOTFOUND = True
-
 from scikits.image import data_dir
 
-_opencv_skip = dec.skipif(OPENCV_LIBS_NOTFOUND,
-                          'OpenCV libraries not found')
+with warnings.catch_warnings():
+    warnings.simplefilter("ignore")
+    from scikits.image import opencv
+
+opencv_skip = dec.skipif(not opencv.libs_found,
+                         'OpenCV libraries not found')
 
 class OpenCVTest:
-    # setup only works as a module level function
-    def __init__(self):
-        self.lena_RGB_U8 = np.load(os.path.join(data_dir, 'lena_RGB_U8.npy'))
-        self.lena_GRAY_U8 = np.load(os.path.join(data_dir, 'lena_GRAY_U8.npy'))
-
+    lena_RGB_U8 = np.load(os.path.join(data_dir, 'lena_RGB_U8.npy'))
+    lena_GRAY_U8 = np.load(os.path.join(data_dir, 'lena_GRAY_U8.npy'))
 
 class TestSobel(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvSobel(self):
         cvSobel(self.lena_GRAY_U8)
 
 
 class TestLaplace(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvLaplace(self):
         cvLaplace(self.lena_GRAY_U8)
 
 
 class TestCanny(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvCanny(self):
         cvCanny(self.lena_GRAY_U8)
 
 
 class TestPreCornerDetect(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvPreCornerDetect(self):
         cvPreCornerDetect(self.lena_GRAY_U8)
 
 
 class TestCornerEigenValsAndVecs(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvCornerEigenValsAndVecs(self):
         cvCornerEigenValsAndVecs(self.lena_GRAY_U8)
 
 
 class TestCornerMinEigenVal(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvCornerMinEigenVal(self):
         cvCornerMinEigenVal(self.lena_GRAY_U8)
 
 
 class TestCornerHarris(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvCornerHarris(self):
         cvCornerHarris(self.lena_GRAY_U8)
 
 
 class TestSmooth(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvSmooth(self):
         for st in (CV_BLUR_NO_SCALE, CV_BLUR, CV_GAUSSIAN, CV_MEDIAN,
                    CV_BILATERAL):
             cvSmooth(self.lena_GRAY_U8, None, st, 3, 0, 0, 0, False)
 
 class TestFindCornerSubPix:
-    @_opencv_skip
+    @opencv_skip
     def test_cvFindCornersSubPix(self):
         img = np.array([[1, 1, 1, 0, 0, 0, 1, 1, 1],
                         [1, 1, 1, 0, 0, 0, 1, 1, 1],
@@ -92,13 +89,13 @@ class TestFindCornerSubPix:
 
 
 class TestGoodFeaturesToTrack(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvGoodFeaturesToTrack(self):
         cvGoodFeaturesToTrack(self.lena_GRAY_U8, 100, 0.1, 3)
 
 
 class TestResize(OpenCVTest):
-    @_opencv_skip
+    @opencv_skip
     def test_cvResize(self):
         cvResize(self.lena_RGB_U8, height=50, width=50, method=CV_INTER_LINEAR)
         cvResize(self.lena_RGB_U8, height=200, width=200, method=CV_INTER_CUBIC)