Displaying the image from a matrix

I am trying to 1)read an image into a matrix 2) Push the values of it inside a vector 3) Read those values back into a Matrix 4) Display it as an image

For this, the code i have coded goes as follows:

#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <stdlib.h>
#include <stdio.h>
#include<iostream>
#include<conio.h>
using namespace std;

using namespace cv;

/** @function main */
int main( int argc, char** argv )
{


 Mat src;
 src = imread("s.png",1);
 imshow("src",src);
 std::vector<unsigned int> a;
 std::vector<unsigned int> m;
 int x1,x2,y1,y2,i,j;
 unsigned int a1=0,c1=0;
 Mat avg=Mat::zeros(src.rows,src.cols,CV_8UC3);
  Mat avg1=Mat::zeros(100,100,CV_8UC1);
 Mat coef=Mat::zeros(http://ift.tt/1wXXdLq);


  for(int i=0;i<src.cols;i++)
 {
     for(int j=0;j<src.rows;j++)
     {
         int x;
         x=(int)src.at<uchar>(j,i);
         m.push_back(x);
     }
  }



 Mat d=Mat::zeros(src.rows,src.cols,CV_8UC3);
    int  g=0;
  for(int i=0;i<src.cols;i++)
 {
     for(int j=0;j<src.rows;j++)
     {
        int l=m.at(g++);
        d.at<uchar>(j,i)=(uchar)l;

     }
  }


  imshow("avg",d);
  waitKey(0);
 getch();

 return 0;
}

On debugging, only half of the input image is getting displayed. Rest half of the image is getting displayed as black.

Kindly let me know where I am going wrong.

Thank you in advance