sagoma/lines.cpp

#include<opencv2/opencv.hpp>

int main(int argc, char *argv[])
{
	cv::Mat img=cv::imread("files/masckera.png",CV_LOAD_IMAGE_GRAYSCALE);

	std::vector< std::vector<cv::Point> > contours;
	std::vector<cv::Vec4i> hierarchy;
	cv::findContours(img,contours,hierarchy,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_SIMPLE);

	cv::drawContours(img,contours,-1,cv::Scalar(255,255,255),5);

	if( 1!=contours.size() )
	{
		std::cout << "non ci piace" << std::endl;
		return -1;
	}

	std::vector<cv::Point> hull;
	cv::convexHull(cv::Mat(contours[0]),hull,false);

	int i;
	int idx[4]={0};
	int distance[2]={0};
	for( i=0; hull.size()>i; i++ )
	{
		cv::Point one=hull[i];
		cv::Point two=hull[(i+1)%hull.size()];
		int d=pow(one.x-two.x,2)+pow(one.y-two.y,2);
		if( d>distance[0] )
		{
			idx[1]=idx[0];
			idx[3]=(idx[1]+1)%hull.size();
			idx[0]=i;
			idx[2]=(idx[0]+1)%hull.size();
			distance[1]=distance[0];
			distance[0]=d;
		}
		else if( d>distance[1] )
		{
			idx[1]=i;
			idx[3]=(i+1)%hull.size();
			distance[1]=d;
		}
	}

	cv::circle(img,hull[idx[0]],30,255,-1);
	cv::circle(img,hull[(idx[0]+1)%hull.size()],30,255,-1);

	cv::circle(img,hull[idx[1]],20,255,-1);
	cv::circle(img,hull[(idx[1]+1)%hull.size()],20,255,-1);
	
	
	std::cout << hull.size() << ", " << contours[0].size() << std::endl;
	std::cout
		<< "(" << idx[0] << "," << distance[0] << ") -- "
		<< "(" << idx[1] << "," << distance[1] << ")" << std::endl;
	cv::namedWindow("test",CV_WINDOW_NORMAL);
	cv::imshow("test",img);
	cv::waitKey(0);

	return 0;
}