Added a more stable detection of opencv library by introducing a new file: _libimport.py

scikits/image/opencv/_libimport.py

@@ -0,0 +1,54 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+"""
+This file properly imports the open CV libraries and returns them
+as an object. This function goes a longer way to try to find them
+since especially on MacOS X Library Paths are not clearly defined.
+
+This module also removes the code duplication in __init__ and
+opencv_cv
+"""
+
+__all__ = [ "import_opencv_lib" ]
+
+import ctypes
+import sys
+
+def import_opencv_lib(which = "cv"):
+    """
+    Try to import a shared library of OpenCV.
+
+    which - Which library ["cv", "cxcore", "highgui"]
+    """
+    if sys.platform.startswith("darwin"):
+        shared_lib = _tryload_macosx(which)
+    elif sys.platform.startswith("linux"):
+        shared_lib = ctypes.CDLL('lib' + which + '.so')
+    else:
+        shared_lib = ctypes.CDLL(which + '.dll')
+
+    if shared_lib is None:
+        raise RuntimeError('The opencv libraries were not found. Please make ' \
+                'sure they are installed and available on the system path.')
+
+def _tryload_macosx(which):
+    common_paths = [
+        '/lib/',
+        '/usr/lib/',
+        '/usr/local/lib',
+        '/opt/local/lib/', # MacPorts
+        '/sw/lib/', # Fink
+    ]
+    shared_lib = None
+    for path in common_paths:
+        try:
+            shared_lib = ctypes.CDLL(path + "lib" + which + '.dylib')
+        except OSError, e:
+            if "image not found" in e.args[0]:
+                continue
+            raise
+
+    return shared_lib
+
+