//环境：VS2010 + OpenCV 2.3.1

#include "stdafx.h"

#include <cv.h>
#include <highgui.h>


#include <math.h>
#include <stdlib.h>
#include <stdio.h>

using namespace cv;

Mat src, dst, tmp;
char* window_name = "Pyramids Demo";

int _tmain(int argc, _TCHAR* argv[])
{
    printf("\n Zoom In-Out demo \n");
    printf("-------------------- \n");
    printf("*[u]-> Zoom in \n");
    printf("*[d]-> Zoom out \n");
    printf("*[ESC]-> Close program \n\n");

    src = imread("D:\\fruits.jpg");
    if(!src.data)
    {
        printf("No data!--Exiting the program \n");
        return -1;
    }

    tmp = src;
    dst = tmp;
    namedWindow(window_name,CV_WINDOW_AUTOSIZE);
    imshow(window_name,dst);

    while(true)
    {
        int c;
        c = waitKey(10);
        if((char)c == 27)
        {
            break;
        }
        if((char)c == 'u')
        {
            pyrUp(tmp,dst,Size(tmp.cols * 2,tmp.rows * 2));
            printf("** Zoom In:Image x 2\n");
        }
        else if((char)c == 'd')
        {
            pyrDown(tmp,dst,Size(tmp.cols / 2,tmp.rows / 2));
            printf("**Zoom Out:Image / 2\n");
        }
        imshow(window_name,dst);
        tmp = dst;
    }
    return 0;
}

#pragma comment(lib,"opencv_highgui231d.lib")