Opencv— — image offset

// define head function
#ifndef PS_ALGORITHM_H_INCLUDED
#define PS_ALGORITHM_H_INCLUDED

#include <iostream>
#include <string>
#include "cv.h"
#include "highgui.h"
#include "cxmat.hpp"
#include "cxcore.hpp"
#include "math.h"

using namespace std;
using namespace cv;

void Show_Image(Mat&, const string &);

#endif // PS_ALGORITHM_H_INCLUDED

/*
Image offset.
*/

#include "PS_Algorithm.h"

int main()
{
string  Image_name("4.jpg");
Mat Img=imread(Image_name.c_str());
Mat Img_out(Img.size(), CV_8UC3);

int warp, xOffset, yOffset;
xOffset=150;
yOffset=100;
warp=1;

int width=Img.cols;
int height=Img.rows;

if (warp)
{
while(xOffset<0)
xOffset=xOffset+width;

while(yOffset<0)
yOffset=yOffset+height;

xOffset=xOffset%width;
yOffset=yOffset%height;
}

int new_x, new_y;

for (int y=0; y<height; y++)
{
for (int x=0; x<width; x++)
{
if(warp)
{
new_x=(x+width-xOffset)%width;
new_y=(y+height-yOffset)%height;
}
else
{
new_x=x-xOffset;
new_y=y-yOffset;
}

if(new_x<0)         new_x=0;
if(new_x>=width-1)  new_x=width-2;
if(new_y<0)         new_y=0;
if(new_y>=height-1) new_y=height-2;

for (int k=0; k<3; k++)
{
Img_out.at<Vec3b>(y, x)[k]=Img.at<Vec3b>(new_y, new_x)[k];

}

}

}

Show_Image(Img_out, "New_img");

// cout<<"All is well."<<endl;
// cout<<xOffset<<endl;
// cout<<yOffset<<endl;
waitKey();
}

// define the show image
#include "PS_Algorithm.h"
#include <iostream>
#include <string>

using namespace std;
using namespace cv;

void Show_Image(Mat& Image, const string& str)
{
namedWindow(str.c_str(),CV_WINDOW_AUTOSIZE);
imshow(str.c_str(), Image);

}