轮廓匹配-Hu不变矩匹配实例代码

#include <iostream>
#include <opencv2/opencv.hpp>
#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>

using namespace std;
using namespace cv;

int main()
{
	// 读取图片
	Mat img1 = imread("digit.png");
	if (img1.empty()) { cerr << "Error: read image failed! \n"; return -1; }
	namedWindow("Input1", WINDOW_AUTOSIZE);
	imshow("Input1", img1);
	Mat img2 = imread("digitSet.png");
	if (img2.empty()) { cerr << "Error: read image failed! \n"; return -1; }
	namedWindow("Input2", WINDOW_AUTOSIZE);
	imshow("Input2", img2);

	cvtColor(img1, img1, COLOR_BGR2GRAY);
	cvtColor(img2, img2, COLOR_BGR2GRAY);

	Mat edge1, edge2;
	//Canny(img1, edge1, 10, 30, 3);  //如果使用canny算子，会出现边缘处存在多次contour，导致误差较大
	//Canny(img2, edge2, 10, 30, 3);
	edge1 = img1;	//由于图片为黑白图像（ppt里面绘制的），可以直接使用
	edge2 = img2;

	// 寻找contour
	vector<vector<Point>> cnt1, cnt2;
	vector<Vec4i> hierarchy1, hierarchy2;
	findContours(edge1, cnt1, hierarchy1, RETR_TREE, CHAIN_APPROX_NONE);
	findContours(edge2, cnt2, hierarchy2, RETR_TREE, CHAIN_APPROX_NONE);

	//绘制找到的边缘contour
	Mat dst1 = Mat::zeros(edge1.rows, edge1.cols, CV_8UC3);
	int idx = 0;
	for (; idx<cnt1.size(); idx++)
	{
		Scalar color(rand() & 255, rand() & 255, rand() & 255);
		drawContours(dst1, cnt1, idx, color, 1, 8, hierarchy1, 1);
	}
	namedWindow("Template", WINDOW_AUTOSIZE);
	imshow("Template", dst1);
	Mat dst2 = Mat::zeros(edge2.rows, edge2.cols, CV_8UC3);
	idx = 0;
	for (; idx<cnt2.size(); idx++)
	{
		Scalar color(rand() & 255, rand() & 255, rand() & 255);
		drawContours(dst2, cnt2, idx, color, 1, 8, hierarchy2, 1);
	}
	namedWindow("TODO", WINDOW_AUTOSIZE);
	imshow("TODO", dst2);

	// 计算HuMoment，并进行匹配
	Moments m1 = moments(cnt1[0], true);
	Mat hu1;
	HuMoments(m1, hu1);
	idx = 0;
	Moments m2;
	Mat hu2;
	Mat result = Mat::zeros(edge2.rows, edge2.cols, CV_8UC3);
	for (; idx < cnt2.size(); idx++) {
		m2 = moments(cnt2[idx], true);
		HuMoments(m2, hu2);
		double likely = matchShapes(hu1, hu2, CONTOURS_MATCH_I1, 1);
		cout << "The HuMoment of index " << idx << ": " << likely << endl;
		if (likely < 0.6) {
			Scalar color(rand() & 255, rand() & 255, rand() & 255);
			drawContours(result, cnt2, idx, color, 1, 8, hierarchy2, 1);
		}
	}
	namedWindow("Result", WINDOW_AUTOSIZE);
	imshow("Result", result);

	// 按Esc键退出
	while (true) { if (27 == waitKey(0)) break; }
	destroyAllWindows();
	return 0;
}

实例图片1： digit.png

实例图片2： digitSet.png