rgbtogray.cpp

#include "opencv2/core/core.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "iostream"
 
using namespace cv;
using namespace std;
 
int main( )
{
 
       Mat image;
       image = imread("Lenna.bmp", CV_LOAD_IMAGE_COLOR);  
 
       if(! image.data )                             
       {
              cout <<  "Could not open or find the image" << std::endl ;
              return -1;
       }
 
       // Create a new matrix to hold the gray image
       Mat gray;
 
       // convert RGB image to gray
       cvtColor(image, gray, CV_BGR2GRAY);
 
       namedWindow( "Display window", CV_WINDOW_AUTOSIZE );  
       imshow( "Display window", image );                 
	
	waitKey(200); 
       namedWindow( "Result window", CV_WINDOW_AUTOSIZE );   
       imshow( "Result window", gray );
 
       waitKey(0);                                          
       return 0;
}