Question

When iterating through a cv::Mat to output all of its values, you could do the following:

for (int r = 0; r < t.rows; r++)
{
    for (int c = 0; c < t.cols; c++)
    {
        std::cout << t.at<float>(r,c) << ", ";
    }
    std::cout << std::endl << std::endl;
}

However, if the information stored in that array is not of type float, this will crash. How do you enforce the type of this matrix?

Answer 1

for 2 Mats nonFloatMat and floatMat when the first is the source matrix and the last is the destination matrix do

nonFloatMat.convertTo(floatMat, CV_32F); //if its a color image use CV_32FC3, or 
                                         // CV_32FC4 if its RGBA

convertTo‘s reference can be found here.

Edit:

and by the way, the code will work if you’ll change the float to the correct concrete type of the matrix ie if the mat is a CV_8U you can do t.at<char>(r,c) etc.