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Checking contour area in opencv with python

I am trying to use the checkContour () function in the new python api (cv2) and it works do if I create the paths that need to be checked using findContours, for example.

contours, hierarchy = cv2.findContours(imgGray, cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
cv2.contourArea(contours[0])

however, when I create the path myself, the following code does not work

contour = numpy.array([[0,0], [10,0], [10,10], [5,4]])
area = cv2.contourArea(contour)

and returns "error: (-215) contour.checkVector (2)> = 0 && (contour.depth () == CV_32F || contour.depth () == CV_32S) in the Area function loop"

when i switch to

contour = numpy.array([[0,0], [10,0], [10,10], [5,4]], dtype=numpy.int32)

I got an "error: (-210) The matrix could not be converted to a sequence of points due to an inappropriate element type in the cvPointSeqFromMat function"

How to make the following code in C ++ from the documentation

vector<Point> contour;
contour.push_back(Point2f(0, 0));
contour.push_back(Point2f(10, 0));
contour.push_back(Point2f(10, 10));
contour.push_back(Point2f(5, 4));

double area0 = contourArea(contour);

work in latest python API (2.3)?

+5
1

:

contour = numpy.array([[[0,0]], [[10,0]], [[10,10]], [[5,4]]])
area = cv2.contourArea(contour)
+11

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