获取轮廓线上的点坐标

旧城等待， 2022-06-16 12:46 198阅读 0赞

参考文献

> http://blog.csdn.net/hw140701/article/details/54381252\#

#include <iostream>   
    #include <fstream>  
    #include <opencv2/opencv.hpp>  
    #include <math.h>  
    using namespace cv;
    using namespace std;
    int main()
    {
    	//载入原始图，且必须以二值图模式载入  
    	Mat M = imread("1.png", 0);
    	imshow("原始图", M);
    
    	//初始化结果图  
    	Mat dstImage = Mat::zeros(M.rows, M.cols, CV_8UC3);
    	int ElementShape = MORPH_RECT;
    
    	Mat element = getStructuringElement(ElementShape, Size(2 * 2 + 1,
    			2 * 2 + 1), Point(2, 2));
    	
    	morphologyEx(M, dstImage, MORPH_OPEN, element, Point(-1, -1), 4);
    	
    	
    		imshow("【开运算】", dstImage);
    	//定义轮廓和层次结构  
    	vector<vector<Point>>contours;
    	vector<Vec4i>hierarchy;
    	findContours(dstImage, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_NONE);
    	//迭代器输出  
    	/*for (vector<vector<Point>>::iterator it=contours.begin();it!=contours.end();++it)
    	{
    	for (vector<Point>::iterator inner_it=it->begin();inner_it!=it->end();++inner_it)
    	{
    	cout<<*inner_it<<endl;
    	}
    	}
    	*/
    	//下标输出  
    	for (int i = 0; i<contours.size(); i++)
    	{
    		for (int j = 0; j<contours[i].size(); j++)
    		{
    			cout << contours[i][j].x << "   " << contours[i][j].y << endl;
    			/*ofstream f;
    			f.open("E:/坐标轮廓线.txt", ios::out | ios::app);
    			f << contours[i][j].x << "  " << contours[i][j].y << endl;*/
    		}
    	}
    
    	//遍历顶层轮廓，以随机颜色绘制出每个连接组件颜色  
    	int index = 0;
    	for (; index >= 0; index = hierarchy[index][0])
    	{
    		Scalar color(rand() % 255, rand() % 255, rand() % 255);
    		drawContours(dstImage, contours, index, color, 1, 8, hierarchy);
    	}
    
    	imshow("轮廓图", dstImage);
    	waitKey(5000); //等待5000ms后窗口自动关闭  
    	getchar();
    }

这篇博客解决了求取轮廓线上的点坐标，又使用了\#include<math.h> 库，终于增加了新的知识。  
获取了点坐标后，就可以用下面三种方式计算像素间的距离：  
//计算欧氏距离的函数  
float calcEuclideanDiatance(int x1, int y1, int x2, int y2)  
\{  
return sqrt(float((x2 - x1)*(x2 - x1) + (y2 - y1)*(y2 - y1)));  
\}

//计算棋盘距离的函数 也叫做马氏距离  
int calcChessboardDistance(int x1, int y1, int x2, int y2)  
\{  
return cv::max(abs(x1 - x2), (y1 - y2));  
\}

//计算麦哈顿距离(街区距离)  
int calcBlockDistance(int x1, int y1, int x2, int y2)  
\{  
return abs(x1 - x2) + abs(y1 - y2);  
\}