从 NumPy 数组到 Mat (OpenCV) 的 C++ 转换

However, I couldn't figure out how to represent an image in Python to pass it to C++. For GUI and camera management I am going to use PyQt, so initially it is going to be QImage, but I can't simply pass it to OpenCV (or I can?). At first, I tried to use nested tuples to represent row, column and color of each pixel, so I ended up with this sample code:

using namespace cv;
namespace py = boost::python;

void display(py::tuple pix)
{
    /*
        Receive image from Python and display it.
    */
    Mat img(py::len(pix), py::len(pix[0]), CV_8UC3, Scalar(0, 0, 255));
    for (int y = 0; y < py::len(pix); y++)
        for (int x = 0; x < py::len(pix[y]); x++)
        {
            Vec3b rgb;
            for (int i = 0; i < 3; i++)
                rgb[i] = py::extract<int>(pix[y][x][i]);
            img.at<Vec3b>(Point(x, y)) = rgb;
        }
    imshow("Image", img);
    waitKey(0);
}

BOOST_PYTHON_MODULE(aruco)
{
    py::def("display", display);
}

事实证明它非常缓慢(单帧几秒钟)，所以我去谷歌搜索并找到了应该更快的解决方案:使用 NumPy 数组，所以代码看起来像这样:

void display(py::object array)
{
    Mat img;
    // ... some magic here to convert NumPy array to Mat ...
    imshow("Image", img);
    waitKey(0);
}