OpenCV从上到下的顺序查找轮廓

#include “opencv2/highgui/highgui.hpp” #include “opencv2/imgproc/imgproc.hpp” #include “opencv2/imgproc/imgproc_c.h” using namespace std; using namespace cv; Mat img,smallImg,gray,bw; vector hierarchy; vector<vector > contours; int threshval=128; Rect r; Rect maxrect,brect; int idx,n; const static Scalar colors[15]={ CV_RGB( 0，0，128)， CV_RGB( 0，128，0)， CV_RGB( 0，128，128)， CV_RGB(128,0,0), CV_RGB(128,0,128), CV_RGB(128,128,0), CV_RGB(128,128,128), CV_RGB(160,160,160), CV_RGB( 0，0，255)， CV_RGB( 0，255，0)， CV_RGB( 0，255，255)， CV_RGB(255,0,0), CV_RGB(255,0,255), CV_RGB(255,255,0), CV_RGB(255,255,255), }; Scalar color; void gamma_correct(Mat& img,Mat& dst,double gamma) { Mat temp; CvMat tmp;

img.convertTo(temp,   CV_32FC1,1.0/255.0,0.0);tmp=temp;cvPow(&tmp,   &tmp,gamma);temp.convertTo(dst ,CV_8UC1 ,255.0    ,0.0);

} int main() { cvNamedWindow(“display”,1); img=imread(“image.jpg”,1); r.x=img.cols/10; r.y=img.rows/3; r.width=img.cols8/10; r.height=img.rows2/3; smallImg=img?; cvtColor(smallImg,gray,CV_BGR2GRAY); // medianBlur(gray,gray,5); equalizeHist(gray,gray); gamma_correct(gray,gray,4.0); imshow(“display”,gray); waitKey(0);

bw=(gray>threshval);imshow("display",bw);waitKey(0);Mat    Structure0=getStructuringElement(MORPH_RECT,Size(3,3));erode(bw,bw,Structure0,Point(-1,-1));Mat    Structure1=getStructuringElement(MORPH_RECT,Size(6,6));dilate(bw,bw,Structure1,Point(-1,-1));imshow("display",bw);waitKey(0);findContours(bw,contours,hierarchy,RETR_EXTERNAL,CHAIN_APPROX_SIMPLE);if (!contours.empty()&&!hierarchy.empty()      idx=0;    n=0;    vector<Point> approx;    for (;idx>=0;idx=hierarchy[idx][0]color=colors[idx];

// drawContours(smallImg,contours,idx,color,1,8,hierarchy); approxPolyDP(Mat(contours[idx]),approx,arcLength(Mat(contours[idx]),true)0.005,true);//0.005是拉直毛边的系数 const Point p = &approx[0]; int m=(int)approx.size(); polylines(smallImg,&p,&m,1,true,color); circle(smallImg,Point(p[0].x,p[0].y),3,color); circle(smallImg,Point(p[1].x,p[1].y),2,color); for (int i=2;i<m;i ) circle(smallImg,Point(p[i].x,p[i].y),1,color); n ; if (1==n) { maxrect=boundingRect(Mat(contours[idx])); } else { brect=boundingRect(Mat(contours[idx])); CvRect mr(maxrect),br(brect); maxrect=cvMaxRect(&mr,&br); } } circle(smallImg,Point(maxrect.x maxrect.width/2,maxrect.y maxrect.height/2),2,CV_RGB(255，0，0) } imshow(“display”,smallImg); waitKey(0); cvDestroyWindow(“display”); return 0; }