一、简介

二、轮廓最小外接矩形的绘制

1 #include "opencv2/opencv.hpp" 2 using namespace cv; 3  4 void main() 5 {     6     //轮廓最小外接矩形的绘制 7     Mat srcImg = imread("E://00.png"); 8     Mat dstImg = srcImg.clone(); 9     cvtColor(srcImg, srcImg, CV_BGR2GRAY);10     threshold(srcImg, srcImg, 100, 255, CV_THRESH_BINARY); //二值化11     imshow("threshold", srcImg);12 13     vector
     
      
       > contours;14     vector
       
         hierarcy;15     findContours(srcImg, contours, hierarcy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);16     vector
        
          boundRect(contours.size());  //定义外接矩形集合17     vector
         
           box(contours.size()); //定义最小外接矩形集合18     Point2f rect[4];19     for(int i=0; i
         
        
       
      
     

三、粗略计算物体像素长宽

1 #include "opencv2/opencv.hpp" 2 #include
     
       3 using namespace std; 4 using namespace cv; 5  6 void main() 7 {     8     Mat srcImg = imread("E://cup.jpg"); 9     imshow("src", srcImg);10     Mat dstImg = srcImg.clone();11     medianBlur(srcImg, srcImg, 5);12     GaussianBlur(srcImg, srcImg, Size(3, 3), 0, 0);13     cvtColor(srcImg, srcImg, CV_BGR2GRAY);14     threshold(srcImg, srcImg, 100, 255, CV_THRESH_BINARY_INV); //INV是因为背景白色，物体黑色，需要反转一下15     imshow("threshold", srcImg);16 17     vector
      
       
        > contours;18     vector
        
          hierarcy;19     20     findContours(srcImg, contours, hierarcy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);21     cout<<"num="<
         
          <
          
            boundRect(contours.size());23 vector
           
             box(contours.size());24 Point2f rect[4];25 for(int i=0; i
           
          
         
        
       
      
     

四、倾斜物体矫正提取

1 #include "opencv2/opencv.hpp" 2 #include
     
       3 using namespace std; 4 using namespace cv; 5  6 void main() 7 {     8     Mat srcImg = imread("E://qrcode.jpg"); 9     imshow("src", srcImg);10     Mat dstImg = srcImg.clone();11     GaussianBlur(srcImg, srcImg, Size(3, 3), 0, 0);12     cvtColor(srcImg, srcImg, CV_BGR2GRAY);13     Canny(srcImg, srcImg, 100, 200);//因为原图比较复杂，所以需要将canny的值调大，去除不想要的成分14     //threshold(srcImg, srcImg, 100, 255, CV_THRESH_BINARY_INV); //二值化也可以实现canny效果,不过在本例中杂絮较多15     imshow("canny", srcImg);16     Mat element = getStructuringElement(MORPH_RECT, Size(11, 11), Point(-1, -1)); //定义结构元素17     dilate(srcImg, srcImg, element); //膨胀18     imshow("dilate", srcImg);19     erode(srcImg, srcImg, element);20     imshow("erode", srcImg);21 22     vector
      
       
        > contours;23     vector
        
          hierarcy;24     findContours(srcImg, contours, hierarcy, CV_RETR_TREE, CV_CHAIN_APPROX_NONE);25     vector
         
           boundRect(contours.size());26     vector
          
            box(contours.size());27 Point2f rect[4];28 for(int i=0; i