OpenCV load images from a folder

opencv_load_folder.cpp

#include "opencv2/opencv.hpp"
#include <iostream>
#include <string>

using namespace cv;
using namespace std;

int main(int, char**)
{
    cv::String path("*.png");
    vector<cv::String> fn;
    vector<Mat> data;
    glob(path, fn, true); // recurse if true
    for(size_t k=0; k<fn.size(); ++k) {
        Mat im = imread(fn[k]);
        if(im.empty()) continue; // continue if failed to load
        data.push_back(im);
    }
    std::string base = "test";
    
    for(int i=0; i<data.size(); i++) {
        std::string name = base + std::to_string(i+1);
        namedWindow(name.c_str());
        imshow(name.c_str(), data[i]);
    }
    waitKey(0);
    return 0;
}