opencv学习之路（22）、轮廓查找与绘制（一）

一、简介

图2

二、代码

#include"opencv2/opencv.hpp"
#include<iostream>
using namespace std;
using namespace cv;

void main()
{
    Mat srcImg = imread("E://02.png"); 
    Mat tempImg = srcImg.clone();
    //Mat draw(srcImg.rows, srcImg.cols, CV_8UC3);
    cvtColor(srcImg, srcImg, CV_BGR2GRAY); //转为灰度图
    threshold(srcImg, srcImg,100, 255, CV_THRESH_BINARY);//图像二值化，value>threshold（即100）?255:0
    imshow("srcImg", srcImg);  //轮廓查找前

    vector<vector<Point>> contours;
    vector<Vec4i> hierarchy;
    //findContours(srcImg, contours, hierarchy,RETR_EXTERNAL, CHAIN_APPROX_SIMPLE ); //查找外轮廓，压缩存储轮廓点
    findContours(srcImg, contours, hierarchy,RETR_LIST, CHAIN_APPROX_SIMPLE ); //查找所有轮廓
    //findContours(srcImg, contours, hierarchy,CV_RETR_CCOMP, CHAIN_APPROX_SIMPLE ); //查找所有轮廓
    //findContours(srcImg, contours, hierarchy,RETR_TREE, CHAIN_APPROX_NONE ); //查找所有轮廓，存储所有轮廓点
    imshow("cont", srcImg);  //轮廓查找后 
    drawContours(tempImg, contours,-1, Scalar(0, 255, 0),2);  //绘制轮廓：-1代表绘制所有轮廓
    cout<<"num="<<contours.size()<<endl; //输出轮廓个数
    imshow("contours", tempImg);

    waitKey(0);
}

 三、小应用

void CImageProcessDlg::OnBnClickedButtonTest() //裂缝检测
{
    // TODO: 在此添加控件通知处理程序代码
    Mat Img=img.clone();
    Mat gray;
    Mat element0=getStructuringElement(MORPH_RECT, Size(5,5));
    Mat element1=getStructuringElement(MORPH_RECT, Size(7,7));
    cvtColor(Img, gray, COLOR_RGB2GRAY );  
    GaussianBlur(gray, gray, Size(25,25), 0, 0);  //---高斯滤波
    adaptiveThreshold(gray, gray, 255, ADAPTIVE_THRESH_GAUSSIAN_C, THRESH_BINARY_INV, 15, 3); //---自适应阈值 
    erode(gray, gray, element0);
    dilate(gray, gray, element1);
    vector<vector<Point> > contours;
    vector<Vec4i> hierarchy;
    findContours(gray, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0));
    drawContours(img, contours, -1, Scalar(0,0,255), 3, 8, hierarchy );
    if(!(img.empty()))
    {
        resize(img, img, Size(rect.Width(),rect.Height()));   //Resize大小
        imshow("PIC",img);  //显示结果
    }
    if(contours.size()>0)
    {
        color_flag=2;
        SetDlgItemText(IDC_EDIT_RESULT0,_T("墙面有裂缝"));
    }
    else
    {
        color_flag=1;
        SetDlgItemText(IDC_EDIT_RESULT0,_T("墙面正常"));
    }
}