【OpenCV】图片尺寸放缩示例程序

这次示例程序分别演示了用resize、pyrUp、pyrDown来让源图像进行放大缩小操作

#include<opencv2/opencv.hpp>
#include<opencv2/imgproc/imgproc.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<iostream>
using namespace std;
using namespace cv;
//====================================
//  定义一些辅助宏
//=====================================
#define WINDOW_NAME "【程序窗口】"

//====================================
//  全局变量声明
//=====================================
Mat g_srcImage, g_dstImage, g_tmpImage;
//操作说明函数
void op()
{
  cout << "\t\t                按键操作说明" << endl;
  cout << "\t\t键盘按下【1】或者【w】—进行基于【resize】函数的图片放大" << endl;
  cout << "\t\t键盘按下【2】或者【s】—进行基于【resize】函数的图片缩小" << endl;
  cout << "\t\t键盘按下【3】或者【a】—进行基于【pyrUp】函数的图片放大" << endl;
  cout << "\t\t键盘按下【4】或者【d】—进行基于【pyrDown】函数的图片缩小" << endl;
}
int main()
{
  system("color 5F");
  op();
  //载入原始图
  g_srcImage = imread("E:\\Pec\\绿巨人.jpg");
  //创建显示窗口
  namedWindow(WINDOW_NAME, WINDOW_AUTOSIZE);
  namedWindow("【原图】", WINDOW_AUTOSIZE);
  imshow("【原图】", g_srcImage);
  //参数赋值
  g_tmpImage = g_srcImage;
  g_dstImage = g_tmpImage;
  int key = 0;
  //轮询获取按键信息
  int i = 1;
  while (1)
  {
    
    key = waitKey(9);
    switch (key)
    {
      case 27://按ESC
        return 0;
        break;
      case 'q':
        return 0;
        break;
    //================图片放大按键处理====================
      case 'a'://按下a，调用pyrUp函数
        pyrUp(g_tmpImage, g_dstImage, Size(g_tmpImage.cols * 2, g_tmpImage.rows * 2));
        cout<<i << "、检测到【a】，图片放大，图片尺寸x2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
      case 'w'://按下w，调用resize函数
        resize(g_tmpImage, g_dstImage, Size(g_tmpImage.cols * 2, g_tmpImage.rows * 2));
        cout <<i<< "、检测到【w】，图片放大，图片基于【resize】函数放大尺寸x2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
      case '1': 
        resize(g_tmpImage, g_dstImage, Size(g_tmpImage.cols * 2, g_tmpImage.rows * 2));
        cout <<i<< "、检测到【1】按下，图片放大，图片基于【resize】函数放大尺寸x2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
      case '3'://调用pyrUp函数
        pyrUp(g_tmpImage, g_dstImage, Size(g_tmpImage.cols * 2, g_tmpImage.rows * 2));
        cout << i<<"、检测到【3】按下，图片放大，图片尺寸x2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
    //================图片缩小按键处理====================
      case 'd'://按下d，调用pyrDown函数
        pyrDown(g_tmpImage, g_dstImage, Size(g_tmpImage.cols / 2, g_tmpImage.rows /2));
        cout <<i<< "、检测到【d】按下图片缩小，图片尺寸/2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
      case 's'://按下s，调用resize函数
        resize(g_tmpImage, g_dstImage, Size(g_tmpImage.cols / 2, g_tmpImage.rows / 2));
        cout <<i<< "、检测到【s】按下，图片缩小，图片基于【resize】函数缩小尺寸/2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
      case '2':
        resize(g_tmpImage, g_dstImage, Size(g_tmpImage.cols / 2, g_tmpImage.rows / 2),
        (0,0),(0,0),2);
        cout <<i<< "、检测到【2】按下，图片缩小，图片基于【resize】函数缩小尺寸/2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
      case '4'://调用pyrUp函数
        pyrDown(g_tmpImage, g_dstImage, Size(g_tmpImage.cols / 2, g_tmpImage.rows / 2));
        cout <<i<< "、检测到【4】按下，图片缩小，图片尺寸/2" << endl;
        i++;
        if (i >= 15)
        {
          i = 0;
          system("cls");
          op();
        }
        break;
    }
    //经过操作后显示变化后的图
    imshow(WINDOW_NAME, g_dstImage);
    //将g_dstImage赋给g_tmpImage，方便下次循环
    g_tmpImage = g_dstImage;

  }

  return 0;
}

原图显示：

通过不断放大缩小得到如下：