* updated python wrapper generator to properly handle C++20-style named parameters

* added sample filter2D[p]() function and a little python test for it to demonstrate the concept

modules/python/test/test_imgproc.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+
+'''
+Test for disctrete fourier transform (dft)
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+
+import cv2 as cv
+import numpy as np
+import sys
+
+from tests_common import NewOpenCVTests
+
+class imgproc_test(NewOpenCVTests):
+    def test_filter2d(self):
+        img = self.get_sample('samples/data/lena.jpg', 1)
+        eps = 0.001
+        # compare 2 ways of computing 3x3 blur using the same function
+        kernel = np.array([[1, 1, 1], [1, 1, 1], [1, 1, 1]], dtype='float32')
+        img_blur0 = cv.filter2D(img, cv.CV_32F, kernel*(1./9))
+        img_blur1 = cv.filter2Dp(img, kernel, ddepth=cv.CV_32F, scale=1./9)
+        self.assertLess(cv.norm(img_blur0 - img_blur1, cv.NORM_INF), eps)
+
+if __name__ == '__main__':
+    NewOpenCVTests.bootstrap()