opencv轮廓提取

#include<opencv2/opencv.hpp>#include<iostream>#include<vector>using namespace std;using namespace cv;int threshval = 160;int main(){Mat img = imread("f:/mei.jpeg");Mat gray ;cvtColor(img,gray,CV_RGB2GRAY);namedWindow("image",WINDOW_AUTOSIZE);imshow("image",img);namedWindow("gray",WINDOW_AUTOSIZE);gray = threshval<160?(gray<threshval):(gray>threshval);imshow("gray",gray);vector<vector<Point> > contours;vector<Vec4i> hierarchy;Mat dst = Mat::zeros(gray.size(),CV_8UC3);findContours(gray,contours,hierarchy,CV_RETR_CCOMP,CV_CHAIN_APPROX_SIMPLE);if(!contours.empty()&&!hierarchy.empty()){int idx = 0;for(;idx>=0;idx=hierarchy[idx][0]){Scalar color(rand()%255,rand()%255,rand()%255);drawContours(dst,contours,idx,color,CV_FILLED,8,hierarchy);}}namedWindow("contours",WINDOW_AUTOSIZE);imshow("contours",dst);waitKey();return 0;}