How can enlarge OpenCV's webcam image?

[John Puskin]

pyramid_up cannot work with opencv image format. Any suggestion?
//// Sample Code....
cv::VideoCapture cap(0);
if (!cap.isOpened())
{
cerr << "Unable to connect to camera" << endl;
return 1;
}
image_window win;
while(!win.is_closed())
{
cv::Mat temp;
cv_image<bgr_pixel> cimg(temp);
//// Below does not work...
/// Any suggestion
while(cimg.size() < 1800*1800)
pyramid_up(cimg);
////
std::vector<rectangle> faces = detector(cimg);
.....
..
}

[John Puskin]

I found this method. However, I am not sure, if it is the correct way of doing it in terms of computational cost.

/////////
cv_image<bgr_pixel> cimg(temp);
matrix<rgb_pixel> img;
assign_image(img, cimg);
pyramid_up(img);
/////////

[Davis]

You either need to use opencv's method for doing it if you want to use
cv::Mat or use the two argument version of pyramid_up().

[John Puskin]

Thanx.

[John Puskin]

I tried this one, but still get compile error.

cv::Mat temp;
if (!cap.read(temp))
{
break;
}
cv_image<bgr_pixel> cimg(temp);
pyramid_down<2> pyr;
pyramid_up(cimg,pyr); // <======

[Davis]

I mean use one that takes 2 images and give something other than an opencv image as output.