OpenCV HoughCircles [英] OpenCV HoughCircles
问题描述
我正在使用Xcode和c ++
Im using Xcode and c++
我已经从 OpenCV文档:
#include <cv.h>
#include <highgui.h>
#include <math.h>
using namespace cv;
int main(int argc, char** argv)
{
Mat img, gray;
if( argc != 2 && !(img=imread(argv[1], 1)).data)
return -1;
cvtColor(img, gray, CV_BGR2GRAY);
// smooth it, otherwise a lot of false circles may be detected
GaussianBlur( gray, gray, Size(9, 9), 2, 2 );
vector<Vec3f> circles;
HoughCircles(gray, circles, CV_HOUGH_GRADIENT,
2, gray->rows/4, 200, 100 );
for( size_t i = 0; i < circles.size(); i++ )
{
Point center(cvRound(circles[i][0]), cvRound(circles[i][1]));
int radius = cvRound(circles[i][2]);
// draw the circle center
circle( img, center, 3, Scalar(0,255,0), -1, 8, 0 );
// draw the circle outline
circle( img, center, radius, Scalar(0,0,255), 3, 8, 0 );
}
namedWindow( "circles", 1 );
imshow( "circles", img );
return 0;
}
然后按如下所示对其进行修改:
then modified it like this:
int main(int argc, char** argv)
{
VideoCapture cap(0);
if(!cap.isOpened())
return -1;
namedWindow( "circles", 1 );
Mat img, gray;
for( ;; )
{
cap >> img;
vector<Vec3f> circles;
cvtColor(img, gray, CV_BGR2GRAY);
GaussianBlur(gray, gray, Size(7,7), 1.5, 1.5);
HoughCircles(img, circles, CV_HOUGH_GRADIENT, 2, img->rows/4, 200, 100 );
imshow( "circles", img );
if(waitKey(30) >= 0) break;
}
return 0;
}
在两种情况下我都收到错误:错误:->"的基本操作数具有非指针类型"cv :: Mat" 然后,我将->替换为.仍然出现另一个错误.这与我从文档中复制的代码相同.
I get the error on both cases: error: base operand of '->' has non-pointer type 'cv::Mat' i then replace the -> with . and still get another error. This is the same with the code that i copied from the documentation.
我的理论是,发生这种情况是因为它没有得到图像和东西.但是当我取出HoughCircles代码时,相机运行正常.
My theory is that this happens because its not getting and image or somehting. but when i take the HoughCircles code out, the camera runs fine.
请问有什么想法吗?
推荐答案
都是编译错误吗?使用.访问 img 成员时会遇到什么错误?我确定您在这种情况下不应该不使用-> ,因为 img 不是指向Mat的指针.
Are both compiling errors? What error do you get when you use . to access img members? I'm certain that you should not use -> in this case since img is not a pointer to Mat.
根据 API参考手册(您应该对此进行抢劫):
According to the API reference manual (you should take a loot at it):
void HoughCircles(Mat& image, vector<Vec3f>& circles, int method, double dp, double minDist, double param1=100, double param2=100, int minRadius=0, int maxRadius=0);
您必须传递对象 img 和 circles 的内存地址,而不是传递对象本身.
You must pass the memory address of the objects img and circles instead of passing the objects themselves.
您应该执行以下操作:
HoughCircles(&img, &circles, CV_HOUGH_GRADIENT, 2, img.rows/4, 200, 100 );
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