RGB to Gray scale Image - OpenCV

rgb_gay.cpp

/*
author : Umanda Jayobandara
*/

#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
using namespace std;
using namespace cv;


int main(int argc, char** argv) {

	String imgName = "umanda.jpg";

	cv::String window_original = "original image";
	cv::String window_gray = "gray image";
	cv::Mat img = cv::imread(imgName);

	if (img.empty())
		std::cout << "failed to open img.jpg" << std::endl;
	else
		std::cout << "img.jpg loaded OK" << std::endl;

	cv::Mat grayMat;

	cv::cvtColor(img, grayMat, cv::COLOR_BGR2GRAY);

	cv::namedWindow(window_original, cv::WINDOW_AUTOSIZE);
	cv::imshow(window_original, img);

	cv::namedWindow(window_gray, cv::WINDOW_AUTOSIZE);
	cv::imshow(window_gray, grayMat);

	cv::waitKey(0);
	return 1;
}