#include <opencv2/opencv.hpp>
#include <iostream>
#include <cstdint>
#include <boost/chrono.hpp>
using namespace std;
int main (int argc, char **argv) {
       if (argc<3)
       {
             cout << "Usage : ./exer5 input.png output.png" << endl;
             return -1;
       }
       //cout << argv[0] << endl;
       //cout << argv[1] << endl;
       //cout << argv[2] << endl;
       cv:: Mat image = cv ::imread(argv[1],cv::IMREAD_COLOR);
       if (image.empty()){
           cout << "Could not lead image " << endl;
           return -2;
       }
       int rows=image.rows;
       int cols=image.cols
       int channels=3;

       //Allocate ***ptr
       uint8_t  ***arr= new uint8_t **[rows];
       for (int i=0;i<row;i++)
       {
            arr[i]=new uint8_t *[cols];
            for (int j=0;j<cols;j++) {
                arr[i][j]=new uint8_t[channels];
            }
       }
       //EOF ALLOC
       //copy image to 3D tensor 
       for (int i=0;i<rows;j++)
       {
             for (int j=0;j<cols;j++)
             {
                  cv::Vec3b pixel=image.at<cv::Vec3b>(i,j);
                  for (int k=0;k<3;k++) {
                      arr[i][j][k]=pixel[k];
                      
             }
       }
       //Transformation

       for(int i=0;i<rows;i++) {
           for (int j=0;j<cols;j++) {
                 uint8_t B=arr[i][j][0];
                 uint8_t G=arr[i][j][0];
                 uint8_t R=arr[i][j][0];
                 uint8_t gray=0.299*R+0.587*G+0.114*B;
                 arr[i][j][0]=gray;
                 arr[i][j][1]=gray;
                 arr[i][j][2]=gray;
          }
       }
       //copy back 
       for (int i=0;i<rows;i++) {
           for (int j=0;j<cols;j++) {
                  image.at<cv::Vec3b>(i,j)[0]=arr[i][j][0];
                  image.at<cv::Vec3b>(i,j)[1]=arr[i][j][1];
                  image.at<cv::Vec3b>(i,j)[2]=arr[i][j][2];
           }
       }
       cv::imwrite(argv[2],image);
       return 0;
}