#include<opencv2/opencv.hpp>
#include<iostream>
#include<vector>

using namespace cv;
using namespace std;

int main()
{
	Mat srcImage = imread("1.jpg");
	imshow("【原圖】", srcImage);

	//先對影象進行空間的轉換（為了之後要提取二值影象）
	Mat grayImage;
	cvtColor(srcImage, grayImage, CV_BGR2GRAY);
	//對影象進行濾波，達到較好的效果
	GaussianBlur(grayImage, grayImage, Size(3, 3), 0, 0);
	imshow("【濾波後的影象】", grayImage);

	//用邊緣檢測的方式獲取二值影象
	Mat cannyImage;
	Canny(grayImage, cannyImage, 128, 255, 3);

	//在二值影象中提取輪廓
	vector<vector<Point>> contours;
	vector<Vec4i> hierarchy;
	findContours(cannyImage, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(0, 0));

	//對每個輪廓的點集 找逼近多邊形
	vector<vector<Point>> approxPoint(contours.size());
	for (int i = 0; i < (int)contours.size(); i++)
	{
		approxPolyDP(contours[i], approxPoint[i], 3, true);
	}

	/******************************************繪製曲線的方式********************************************/
	//用繪製輪廓的函式   繪製曲線
	Mat drawImage = Mat::zeros(srcImage.size(), CV_8UC3);
	for (int i = 0; i < (int)contours.size(); i++)
	{
		drawContours(drawImage, contours, i, Scalar(255, 255, 255), 1);
	}

	imshow("【繪製後的影象】", drawImage);

	waitKey(0);

	return 0;
}