Backport of new python tests from master branch(PR https://github.com/Itseez/opencv/pull/6025).

At the moment tests requre samples/data copied to source location from master branch.

modules/python/test/test_morphology.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python
+
+'''
+Morphology operations.
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+import sys
+PY3 = sys.version_info[0] == 3
+
+import numpy as np
+import cv2
+
+from tests_common import NewOpenCVTests
+
+class morphology_test(NewOpenCVTests):
+
+    def test_morphology(self):
+
+        fn = 'samples/data/rubberwhale1.png'
+        img = self.get_sample(fn)
+
+        modes = ['erode/dilate', 'open/close', 'blackhat/tophat', 'gradient']
+        str_modes = ['ellipse', 'rect', 'cross']
+
+        referenceHashes = { modes[0]: '071a526425b79e45b4d0d71ef51b0562', modes[1] : '071a526425b79e45b4d0d71ef51b0562',
+            modes[2] : '427e89f581b7df1b60a831b1ed4c8618', modes[3] : '0dd8ad251088a63d0dd022bcdc57361c'}
+
+        def update(cur_mode):
+            cur_str_mode = str_modes[0]
+            sz = 10
+            iters = 1
+            opers = cur_mode.split('/')
+            if len(opers) > 1:
+                sz = sz - 10
+                op = opers[sz > 0]
+                sz = abs(sz)
+            else:
+                op = opers[0]
+            sz = sz*2+1
+
+            str_name = 'MORPH_' + cur_str_mode.upper()
+            oper_name = 'MORPH_' + op.upper()
+
+            st = cv2.getStructuringElement(getattr(cv2, str_name), (sz, sz))
+            return cv2.morphologyEx(img, getattr(cv2, oper_name), st, iterations=iters)
+
+        for mode in modes:
+            res = update(mode)
+            self.assertEqual(self.hashimg(res), referenceHashes[mode])