1 // liantongyu.cpp : 定义控制台应用程序的入口点。
  2 //
  3 
  4 #include "stdafx.h"
  5 #include <iostream>
  6 #include<numeric>
  7 #include<opencv2\opencv.hpp>
  8 #include <opencv2/core/core.hpp>
  9 #include <opencv2/imgproc/imgproc.hpp>
 10 #include <opencv2/highgui/highgui.hpp>
 11 #include <opencv2/video/video.hpp>  
 12 
 13 using namespace cv;
 14 using namespace std;
 15 
 16 void contourDelete(Mat &bwImg, Mat &bwImg1, Rect &rect)
 17 {
 18     for (int y = rect.y; y < rect.y + rect.height; y++)
 19     {
 20         for (int x = rect.x; x < rect.x + rect.width; x++)
 21         {
 22             const uchar *inData = bwImg.ptr<uchar>(y)+x;
 23             uchar *outData = bwImg1.ptr<uchar>(y) + x;
 24             if (inData[0]==255)
 25             {
 26                 outData[0] = 0;
 27             }
 28         }
 29     }
 30 
 31 }
 32 
 33 int main()
 34 {
 35     Mat bwImg,srcImg, bwImg1;
 36     srcImg = imread("14.jpg");
 37     vector<vector<Point>> contours;
 38 
 39     imshow("original image", srcImg);
 40 
 41     //灰度转换+阈值+形态操作
 42     cvtColor(srcImg, srcImg, CV_BGR2GRAY);
 43     threshold(srcImg, bwImg, 0.0, 255.0, CV_THRESH_BINARY | CV_THRESH_OTSU);
 44     Mat element = getStructuringElement(CV_SHAPE_ELLIPSE, Size(5, 5));
 45     morphologyEx(bwImg, bwImg, MORPH_OPEN, element);
 46     
 47     //复制得到bwImage1
 48     bwImg1 = bwImg.clone();
 49 
 50     imshow("binary image", bwImg);
 51     imshow("bwImg1", bwImg1);
 52 
 53     // 查找轮廓，对应连通域
 54     findContours(bwImg, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);
 55 
 56     // 寻找最大连通域
 57     double maxArea = 0;
 58     vector<Point> maxContour;
 59     for (size_t i = 0; i < contours.size(); i++)
 60     {
 61         double area = contourArea(contours[i]);
 62         if (area > maxArea)
 63         {
 64             maxArea = area;
 65             maxContour = contours[i];
 66         }
 67     }
 68 
 69     //输出最大连通区域面积
 70     cout << "最大的连通区域面积是：" << maxArea;
 71 
 72     //删除除最大连通域外的所有小连通域
 73     for (size_t i = 0; i < contours.size(); i++)
 74     {
 75         double area = contourArea(contours[i]);
 76         Rect rect = boundingRect(contours[i]);
 77         if (area < maxArea)
 78         {
 79             contourDelete(bwImg,bwImg1,rect);
 80         }
 81     }
 82 
 83     // 将轮廓转为矩形框
 84     Rect maxRect =boundingRect(maxContour);
 85 
 86     // 显示连通域
 87     Mat result1, result2;
 88     bwImg.copyTo(result1);
 89     bwImg1.copyTo(result2);
 90 
 91     //显示所有轮廓矩形框
 92     for (size_t i = 0; i < contours.size(); i++)
 93     {
 94         Rect r = boundingRect(contours[i]);
 95         rectangle(result1, r,Scalar(255));
 96     }
 97     imshow("all regions", result1);
 98 
 99     //显示最大轮廓矩形框
100     rectangle(result2, maxRect,Scalar(255));
101     imshow("largest region", result2);
102     imshow("最终结果",bwImg1);
103     waitKey();
104     return 0;
105 }