Finding the center of a contour using opencv and visual c++

Question

I want to find the center of a contour without doing so much calculations. Is there a built in function for that in opencv?

To answer your question: There is no built in function. Checkout berak for copypasta code that solves your problem. — Sebastian Schmitz, Mar 14 '14 at 09:16

score 15 · Accepted Answer · answered Mar 14 '14 at 08:07

15

for the 'geometric center', get the boundingRect() of the contour, then:

   cx = br.x+br.width/2; cy = br.y+br.height/2;

for the 'center of mass' get the moments() of the contour, then:

   cx = m.m10 / m.m00;   cy = m.m01 / m.m00;

answered Mar 14 '14 at 08:07

berak

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Thank your answer was easy to implement not complicated like examples that I found. – shahd Mar 14 '14 at 09:17
Using "moments" can fail with ZeroDivisionError because of bad contours, see https://stackoverflow.com/a/35247571/1619432 (no proper solution given). – handle Oct 14 '18 at 16:38

score 0 · Answer 2 · edited May 23 '17 at 11:53

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Either you haven't done any research, or these questions already asked and answered here are not what you are asking:

centroid of contour/object in opencv in c?

OpenCV 2 Centroid

If latter is the case, please elaborate the question in more detail.

edited May 23 '17 at 11:53

Community

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answered Mar 14 '14 at 08:05

bosnjak

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score 0 · Answer 3 · answered Jan 19 '22 at 12:45

hope this could help you. this link has python and C++ code snippet

std::vector<cv::Point> centers; 
for (int i=0; i<contours.size(); i++){
     cv::Moments M = cv::moments(contours[i]);
     cv::Point center(M.m10/M.m00, M.m01/M.m00);
     centers.push_back(center);
}

Finding the center of a contour using opencv and visual c++

3 Answers3

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