OpenCV中绘制外围矩形框和圆框

利用边界寻找函数找到的边界坐标信息。然后利用每一条寻找到的边际信息去找到图形的矩形边界和圆形边界。

一、 OpenCV中绘制外围矩形框

根据已知的边界信息点。将边界信息传入提供的API函数得到该边界的矩形框。

API:Rect boundingRect(Mat(输入点集));

下面是具体的使用方法:

void rec(int,void*) { Mat out_put; vector<vector<Point>> contours; vector<Vec4i> hierarchy; Canny(src_gray,dst,thres,2*thres); findContours(dst,contours,hierarchy,CV_RETR_TREE,CV_CHAIN_APPROX_SIMPLE,Point(0,0)); vector<Rect> rect_size(contours.size()); vector<Point2f> circle_p(contours.size()); vector<float> circle_r(contours.size()); for(int i = 0;i < contours.size();i++) { rect_size[i] = boundingRect(Mat(contours[i])); } out_put = Mat::zeros(src.size(),CV_8UC3); for(int i = 0;i < rect_size.size();i++) { rectangle(out_put,rect_size[i],Scalar(0,255,0),2,8); } imshow("out_put",out_put); }

OpenCV中绘制外围圆形框

根据已经知道的边界信息点，得到圆形框的圆心(存储类型vector)和半径(存储类型vector)。

minEnclosingCircle( Mat(输入点集)， Point2f& 圆心， float& 半径， );

具体的使用方法如下:

void rec(int,void*) { Mat out_put; vector<vector<Point>> contours; vector<Vec4i> hierarchy; Canny(src_gray,dst,thres,2*thres); findContours(dst,contours,hierarchy,CV_RETR_TREE,CV_CHAIN_APPROX_SIMPLE,Point(0,0)); vector<Rect> rect_size(contours.size()); vector<Point2f> circle_p(contours.size()); vector<float> circle_r(contours.size()); for(int i = 0;i < contours.size();i++) { rect_size[i] = boundingRect(Mat(contours[i])); minEnclosingCircle(Mat(contours[i]),circle_p[i],circle_r[i]); } out_put = Mat::zeros(src.size(),CV_8UC3); for(int i = 0;i < rect_size.size();i++) { // rectangle(out_put,rect_size[i],Scalar(0,255,0),2,8); circle(out_put,circle_p[i],circle_r[i],Scalar(0,0,255),2,8); } imshow("out_put",out_put); }

全部的代码如下:

#include "opencv2/highgui/highgui_c.h" #include "opencv2/opencv.hpp" #include<iostream> using namespace std; using namespace cv; Mat src,src_gray,dst; int thres = 100; void rec(int,void*); int main() { src = imread("/home/dynamicw/Project/C++_Project/opencvtest/src/lesson01/source/map.png"); cvtColor(src,src_gray,COLOR_BGR2GRAY); blur(src_gray,src_gray,Size(3,3)); imshow("src_gray",src_gray); namedWindow("test",CV_WINDOW_AUTOSIZE); createTrackbar("value","test",&thres,255,rec); rec(0,0); waitKey(0); return 0; } void rec(int,void*) { Mat out_put; vector<vector<Point>> contours; vector<Vec4i> hierarchy; Canny(src_gray,dst,thres,2*thres); findContours(dst,contours,hierarchy,CV_RETR_TREE,CV_CHAIN_APPROX_SIMPLE,Point(0,0)); vector<Rect> rect_size(contours.size()); vector<Point2f> circle_p(contours.size()); vector<float> circle_r(contours.size()); for(int i = 0;i < contours.size();i++) { rect_size[i] = boundingRect(Mat(contours[i])); minEnclosingCircle(Mat(contours[i]),circle_p[i],circle_r[i]); } out_put = Mat::zeros(src.size(),CV_8UC3); for(int i = 0;i < rect_size.size();i++) { // rectangle(out_put,rect_size[i],Scalar(0,255,0),2,8); circle(out_put,circle_p[i],circle_r[i],Scalar(0,0,255),2,8); } imshow("out_put",out_put); }