#include <string>
#include "iostream"
#include "time.h"
#include "windows.h"

using namespace std;

int main()
{
	int image[600][800];
	int block[5][5];
	double MSE = 0;
	double min = 1000000;					// initial value is just a big number
	int BlockNumOfPixels = sizeof block; 	// the number of pixels for calculating MSE
	int Coordinates[100][2]; 				// the Coordination of the beginning pixels for minimmum MSEs 
	int b = 0; 								// iterator of Coordinates array

	//generate random numbers for image pixels	
	for (int i = 0; i < sizeof image / sizeof image[0]; i++) {
		for (int j = 0; j < sizeof image[0] / sizeof(int); j++) {
			image[i][j] = rand() % 256;
		}
	}

	//generate random numbers for block pixels
	cout<<"\n\n"<<"Block image pixels: \n\n";
	for (int i = 0; i < sizeof block / sizeof block[0]; i++) {
		for (int j = 0; j < sizeof block[0] / sizeof(int); j++) {
			block[i][j] = rand() % 256;
			cout<<block[i][j]<<" ";
		}
		cout<<"\n";
	}

	int i, j, m, n;
	clock_t tStart = clock(); // start timer
	
	for (i = 0; i < ((sizeof image / sizeof image[0]) - (sizeof block / sizeof block[0])); i++) {
		for (j = 0; j < ((sizeof image[0] / sizeof (int)) - (sizeof block[0] / sizeof(int))); j++) {
			MSE = 0; // befor starting to calculate, set MSE to 0 
			for (m = 0; m < (sizeof block / sizeof block[0]); m++) {
				for (n = 0; n < (sizeof block[0] / sizeof(int)); n++) {
					MSE += ((image[i+m][j+n] - block[m][n]) * (image[i+m][j+n] - block[m][n]));
				}
			}
			MSE /= BlockNumOfPixels;

			if (min >= MSE) {
				if (min > MSE) {//new MSE found!					
					b = 0;
					//add the coordination of MSE
					Coordinates[b][0] = i;
					Coordinates[b++][1] = j;
				}
				else {// same MSE found! just add the coordination
					Coordinates[b][0] = i;
					Coordinates[b++][1] = j;
				}
				min = MSE; // set the new minimmum MSE 
			}
		}		
	}
	cout<<"\n\n";
	printf("Time taken: %.5f Second\n", (double)(clock() - tStart) / CLOCKS_PER_SEC);

	cout<<"\n\n"<<"MSE "<<min<<" found at below coordination(s) :\n";
	for (int a = 0; a < b; a++) {
		cout<<"\n\n"<<"(x,y)="<<"("<<Coordinates[a][1]<<","<<Coordinates[a][0]<<")"<<"\n\n";	
		for (int i = 0; i < (sizeof block / sizeof block[0]); i++) {			
			for (int j = 0; j < (sizeof block[0] / sizeof(int)); j++) {							
				cout<<image[Coordinates[a][0]+i][Coordinates[a][1]+j]<<" ";			
			}cout<<"\n";
		}cout<<"\n";
	}			
	
	return 0;
}