Merge pull request #20558 from alalek:python_cv_mat

modules/core/misc/python/package/mat_wrapper/__init__.py

@@ -0,0 +1,33 @@
+__all__ = []
+
+import sys
+import numpy as np
+import cv2 as cv
+
+# NumPy documentation: https://numpy.org/doc/stable/user/basics.subclassing.html
+
+class Mat(np.ndarray):
+    '''
+    cv.Mat wrapper for numpy array.
+
+    Stores extra metadata information how to interpret and process of numpy array for underlying C++ code.
+    '''
+
+    def __new__(cls, arr, **kwargs):
+        obj = arr.view(Mat)
+        return obj
+
+    def __init__(self, arr, **kwargs):
+        self.wrap_channels = kwargs.pop('wrap_channels', getattr(arr, 'wrap_channels', False))
+        if len(kwargs) > 0:
+            raise TypeError('Unknown parameters: {}'.format(repr(kwargs)))
+
+    def __array_finalize__(self, obj):
+        if obj is None:
+            return
+        self.wrap_channels = getattr(obj, 'wrap_channels', None)
+
+
+Mat.__module__ = cv.__name__
+cv.Mat = Mat
+cv._registerMatType(Mat)