图像加减运算，为什么输出结果不对

#include
#include
#include
#include

#include

using namespace std;

//图像加减运算
//unsigned char *lpSrc1:原图像1像素指针
//unsigned char *lpSrc2:原图像2像素指针
//unsigned char *lpDst：目标像素指针

int main()
{
IplImage * image1, *image2, *image3;
image1 = cvLoadImage("1.jpg", 0);
image2 = cvLoadImage("2.jpg", 0);
cvNamedWindow("image1", CV_WINDOW_AUTOSIZE);
cvNamedWindow("image2", CV_WINDOW_AUTOSIZE);
cvNamedWindow("image3", CV_WINDOW_AUTOSIZE);
cvSaveImage("1.jpg", image1, 0);
cvSaveImage("2.jpg", image2, 0);
cvShowImage("image1", image1);
cvShowImage("image2", image2);
image3 = cvCreateImage(cvGetSize(image1), image1->depth, 1);

unsigned char *lpSrc1;
unsigned char *lpSrc2;
unsigned char *lpDst;

int i, j;

for ( i = 0; i < image1->height;i++) 

    for ( j = 0; j< image1->width;j++)
    {
        lpSrc1 = (unsigned char *)image1->imageData + i*image1->widthStep + j;


        for (i = 0; i < image2->height;i++)

            for (j = 0; j < image2->width;j++)
            {
                lpSrc2 = (unsigned char *)image2->imageData + i*image2->widthStep + j;


                lpDst = (unsigned char *)image3->imageData + i*image3->widthStep + j;


                if ((*lpSrc1 + *lpSrc2) > 255)
                    *lpDst = 255;
                else
                    *lpDst = (*lpSrc1 + *lpSrc2);

            }
    }




cvShowImage("image3", image3);
cvWaitKey(0);
return 0;

}

图像加减运算，为什么输出结果不对

请问你下面的图是怎么弄的啊，我发问题，图片总是看不清