Import 2D matrix in 3D matrix using OpenCV - c++

Question

This function:
filtro.kernel(n, mat)
returns a 2D matrix with 15x15 size, is there a way to add all 12 matrices that are calculated from the for cycle to a 3D matrix with size 12,15,15?
#include <opencv2/core/core.hpp>
#include <opencv2/core/core.hpp>
#include "filter.h"
#include <iostream>
int main(){
using namespace cv;
using namespace std;
cv::Mat mat = cv::Mat::zeros(15, 15, CV_32S);
filter filtro;
for (int n = 0; n < 12; n++){
filtro.kernel(n, mat);
cout<<"Angle Matrix"<<endl;
cout<< n*15 <<endl;
cout<< mat <<endl;
}
return 0;
}

Answer 1

You can use cv::merge to create a multi-channels matrix. But notice, the channels dimension is the last.12 (15,15) => (15,15,12)
Try this:
#include <opencv2/core/core.hpp>
#include <opencv2/core/core.hpp>
#include "filter.h"
#include <iostream>
int main(){
using namespace cv;
using namespace std;
filter filtro;
// Create a vector of Mat
vector<Mat> mats;
for (int n = 0; n < 12; n++){
cv::Mat mat = cv::Mat::zeros(15, 15, CV_32S);
filtro.kernel(n, mat);
cout<<"Angle Matrix"<<endl;
cout<< n*15 <<endl;
cout<< mat <<endl;
mats.push_back(mat);
}
// Merge the Mats
Mat dst;
merge(mats, dst);
return 0;
}