#include <opencv2/opencv.hpp>
#include <iostream>
#include <cstdint>
#include <boost/chrono.hpp>
//this takes a 2d colored image, the 3d of time and return a gray  2d image

using namespace std;

int main (int argc, char **argv) {
	if (argc<3)
	{
		cout << "Usage: ./as5 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 load image" << endl;
		return -2;
		}
	int rows=image.rows;
	int cols=image.cols;
	int channels=3;

	//alocate pointer
	uint8_t ***arr= new uint8_t **[rows]
	for (int i=0; i<rows; i++)
	{
		arr[i]=new uint8_t *[rows];
		for (int j=0; j<cols; j++){
			arr[i][j]=new uint8_t[channels]
			}
		}
	//end of alloc

	//cp image to 3D tensor
	for (int i=0: i<rows; i++){
		
		for (int j=0; j<cols; j++){

			cv: :Vec3b pixel=image.at<cv::Vec4b>(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::imrite(argv[2],image);
	return 0;
}