Opencv 3仿射變換之縮放 平移 旋轉 傾斜 反射 透視

 仿射變換涉及大量的關于矩陣的運算，這裡就不在過多講解了，關于矩陣參考如下：       
         
  
   http://blog.csdn.net/myan/article/details/647511

  
  

  
  
   
    https://www.zhihu.com/question/19919917/answer/270694029?utm_source=qq&utm_medium=social

   

  
        
 仿射變換的概念：很通俗易懂       
         
  
   https://www.zhihu.com/question/20666664

  
        
 //仿射變換  縮放 平移  旋轉   傾斜   反射  透視       
          
#include<iostream>
#include<opencv2\opencv.hpp>
using namespace std;
using namespace cv;

int main(void)
{
	Mat src = imread("C:/Users/11741/Desktop/image/high.jpg");    //原圖
	if (!src.data)
		return -1;
	cout << "1.縮放" << endl;
	cout << "2.平移" << endl;
	cout << "3.旋轉" << endl;
	cout << "4.傾斜" << endl;
	cout << "5.反射" << endl;
	cout << "6.透視" << endl;
	int num;
	while (1)
	{
		cin >> num;
		switch (num)
		{
		case 1:
		{
			Mat dst;
			resize(src, dst, Size(0, 0), 0.5, 0.5, 1);    //參數一：原圖；參數二：目标圖；如果參數三為0，則按參數四計算，參數四為縮放因子；參數三為縮放大小
			imshow("src", src);                 //顯示原圖
			imshow("dst", dst);                 //顯示目标圖
			waitKey(0);
			break;
		}
		case 2:
		{
			Mat dst;
			Mat M = (Mat_<double>(2, 3) << 1, 0, 200, 0, 1, 150);            //建構平移矩陣，表示x方向平移200，y方向平移150
			warpAffine(src, dst, M, src.size());                     //進行仿射變換，參數三為變換的矩陣，參數四：目标圖大小
			imshow("src", src);
			imshow("dst", dst);
			waitKey(0);
			break;
		}
		case 3:
		{ 
			Mat dst;
			Mat M = getRotationMatrix2D(Point2f(0,src.rows), 40, 1);       //擷取變換矩陣，參數一：旋轉中心；參數二：角度（逆時針）；參數三：縮放因子
			warpAffine(src, dst, M, src.size());                                //進行仿射變換
			imshow("src", src);
			imshow("dst", dst);
			waitKey(0);
			break;
		}
		case 4:
		{
			Mat dst; 
			Point2f srcTriangle[3];              //目标圖和源圖像設定三組點計算仿射變換
			Point2f dstTriangle[3];              
			srcTriangle[0] = Point2f(0, 0);
			srcTriangle[1] = Point2f(src.cols - 1, 0);
			srcTriangle[2] = Point2f(0, src.rows - 1);

			dstTriangle[0] = Point2f(0, src.rows*0.33);
			dstTriangle[1] = Point2f(src.cols*0.65, src.rows*0.35);
			dstTriangle[2] = Point2f(src.cols*0.15, src.rows*0.6);
			Mat M = getAffineTransform(srcTriangle, dstTriangle);          //擷取變換矩陣
			warpAffine(src, dst, M, src.size());
			imshow("src", src);
			imshow("dst", dst);
			waitKey(0);
			break;
		}
		case 5:
		{
			Mat dst;
			Mat Mh = (Mat_<double>(2, 3) << -1, 0, src.cols, 0, 1, 0);     //水準
			Mat Mv = (Mat_<double>(2, 3) << 1, 0, 0, 0, -1, src.rows);      //垂直
			Mat M = (Mat_<double>(2, 3) << -1, 0, src.cols, 0, -1, src.rows);  //水準+垂直
			warpAffine(src, dst, Mh, src.size()); 
			imshow("src", src);
			imshow("dst", dst);
			waitKey(0);
			break;
		}
		case 6:
		{
			Mat dst;
			Point2f srcMar[4];
			Point2f dstMar[4];                             //目标圖與原圖設定四組點
			srcMar[0] = Point(0, 0);
			srcMar[1] = Point(src.cols - 1, 0);
			srcMar[2] = Point(0, src.rows - 1);
			srcMar[3] = Point(src.cols - 1, src.rows - 1);
			dstMar[0] = Point(src.cols*0.4, src.rows*0.3);
			dstMar[1] = Point(src.cols*0.7,src.rows*0.1);
			dstMar[2] = Point(src.cols*0.1, src.rows*0.8);
			dstMar[3] = Point(src.cols*0.8, src.rows*0.9);
			Mat M = getPerspectiveTransform(srcMar, dstMar);         //擷取透視矩陣
			warpPerspective(src, dst, M, src.size());
			imshow("src", src);
			imshow("dst", dst);
			waitKey(0);
			break;
		} 
		default:
			return 0;
			break;
		}
	}
	waitKey(0);
	return 0;
}