Opencv Mat as parameter of a function

Question

I have a trouble now with opencv Mat.

Here's a function

void getMat(Mat a){

   double b[3]={1,2,3};

   a=Mat(3,1,CV_64FC1,b);

}

When I use the function in main

Mat mat(3,1,CV_64FC1);

getMat(mat);

but the result of mat is

[-9.255963134931783e+61;
  -9.255963134931783e+61;
  -9.255963134931783e+61]

so could someone help me out of the problem?

Thanks very much

Best

Jing

https://stackoverflow.com/questions/410593/pass-by-reference-value-in-c — Dmitrii Z., Dec 25 '17 at 10:50

score 2 · Answer 1 · answered Dec 25 '17 at 11:09

2

Use reference parameter, and copyTo the object;

#include <iostream>
#include <opencv2/opencv.hpp>
using namespace std;
using namespace cv;

void getMat(Mat &mat){
   double b[3]={1,2,3};
   Mat _mat(3,1,CV_64FC1,b);
   _mat.copyTo(mat);
}

int main(){
    Mat a;
    getMat(a);
    cout << a <<endl;
    return 0;
}

/*
[1;
 2;
 3]
*/

answered Dec 25 '17 at 11:09

Kinght 金

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Thanks very much~ Merry Christmas~ – Windsor_Gu Dec 25 '17 at 11:23
Merry Christmas ~ (We keep Spring Festival in China – Kinght 金 Dec 25 '17 at 11:27

Opencv Mat as parameter of a function

1 Answers1