//　https://qiita.com/litll_li/items/378e56b4b6877ea6676f中のhoge.cpp
#include <iostream>
#include <opencv2/opencv.hpp>

int main() {
  cv::Mat img, img_rgb;

  img = cv::imread("sample.jpg");
  // error handling
  if(img.data == NULL) {
    std::cerr << "Error: not found such file." << std::endl;
    exit(1);
  }
  // convert BGR to RGB
  cv::cvtColor(img, img_rgb, cv::COLOR_BGR2RGB);

  // print pixel data
  std::cout << img_rgb << std::endl;
}