opencv2 鼠標事件與模板匹配

任務：利用鼠標在給定圖像上選取矩形，第一作爲模板，之後作爲匹配圖像。

參考：opencv2 使用鼠標繪製矩形並截取和保存矩形區域圖像

利用模板匹配計算兩幅圖像的相似度：

double GetMatchVal(Mat& src, Mat& tpl)  
{  
    double dis = 0.0;  
    if (!src.data || !tpl.data)  
        return dis;  
  
    //判斷兩幅圖像的大小關係，如果輸入的原始圖像比匹配圖像要小，則將原始圖像作爲模板，原來的模板圖像作爲搜索圖    
    //模板匹配算法中已經包含了這一段  
    if (src.rows < tpl.rows || src.cols < tpl.cols)  
        std::swap(src, tpl);  
    int result_cols = src.cols - tpl.cols + 1;  
    int result_rows = src.rows - tpl.rows + 1;  
    if (result_cols <= 0 || result_rows <= 0) {  
        return dis;  
    }  
  
    Mat result = Mat::zeros(result_rows, result_cols, CV_32FC1);  
    matchTemplate(src, tpl, result, CV_TM_CCOEFF_NORMED);  
  
    double minVal = 0.0, maxVal = 0.0;  
    Point minLoc, maxLoc;  
    minMaxLoc(result, NULL, &maxVal, NULL, &maxLoc);  
    result.release();  
    dis = maxVal;  
    return dis;  
}  

#include <opencv2/core/core.hpp>  
#include <opencv2/imgproc/imgproc.hpp>  
#include <opencv2/highgui/highgui.hpp>  
#include <opencv2\features2d\features2d.hpp>
#include <opencv2\nonfree\features2d.hpp>
#include <iostream>
using namespace cv;

cv::Mat org, dst, img, tmp,model;
bool first = false;
double GetMatchVal(Mat& src, Mat& tpl)
{
	double dis = 0.0;

	if (!src.data || !tpl.data)
		return dis;

	//判斷兩幅圖像的大小關係，如果輸入的原始圖像比匹配圖像要小，則將原始圖像作爲模板，原來的模板圖像作爲搜索圖  
	//模板匹配算法中已經包含了這一段
	if (src.rows < tpl.rows || src.cols < tpl.cols)
		std::swap(src, tpl);

	int result_cols = src.cols - tpl.cols + 1;
	int result_rows = src.rows - tpl.rows + 1;
	if (result_cols <= 0 || result_rows <= 0) {
		return dis;
	}


	Mat result = Mat::zeros(result_rows, result_cols, CV_32FC1);
	matchTemplate(src, tpl, result, CV_TM_CCOEFF_NORMED);

	double minVal = 0.0, maxVal = 0.0;
	Point minLoc, maxLoc;
	minMaxLoc(result, NULL, &maxVal, NULL, &maxLoc);
	result.release();
	dis = maxVal;

	return dis;
}
void on_mouse(int event, int x, int y, int flags, void *ustc)//event鼠標事件代號，x,y鼠標座標，flags拖拽和鍵盤操作的代號
{
	static Point pre_pt = (-1, -1);//初始座標
	static Point cur_pt = (-1, -1);//實時座標
	char temp[16];
	if (event == CV_EVENT_LBUTTONDOWN)//左鍵按下，讀取初始座標，並在圖像上該點處劃圓
	{
		org.copyTo(img);//將原始圖片複製到img中
		sprintf(temp, "(%d,%d)", x, y);
		pre_pt = Point(x, y);
		putText(img, temp, pre_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255), 1, 8);//在窗口上顯示座標
		circle(img, pre_pt, 2, Scalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);//劃圓
		imshow("img", img);
	}
	else if (event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))//左鍵沒有按下的情況下鼠標移動的處理函數
	{
		img.copyTo(tmp);//將img複製到臨時圖像tmp上，用於顯示實時座標
		sprintf(temp, "(%d,%d)", x, y);
		cur_pt = Point(x, y);
		putText(tmp, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));//只是實時顯示鼠標移動的座標
		imshow("img", tmp);
	}
	else if (event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))//左鍵按下時，鼠標移動，則在圖像上劃矩形
	{
		img.copyTo(tmp);
		sprintf(temp, "(%d,%d)", x, y);
		cur_pt = Point(x, y);
		putText(tmp, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));
		rectangle(tmp, pre_pt, cur_pt, Scalar(0, 255, 0, 0), 1, 8, 0);//在臨時圖像上實時顯示鼠標拖動時形成的矩形
		imshow("img", tmp);
	}
	else if (event == CV_EVENT_LBUTTONUP)//左鍵鬆開，將在圖像上劃矩形
	{
		org.copyTo(img);
		sprintf(temp, "(%d,%d)", x, y);
		cur_pt = Point(x, y);
		putText(img, temp, cur_pt, FONT_HERSHEY_SIMPLEX, 0.5, Scalar(0, 0, 0, 255));
		circle(img, pre_pt, 2, Scalar(255, 0, 0, 0), CV_FILLED, CV_AA, 0);
		rectangle(img, pre_pt, cur_pt, Scalar(0, 255, 0, 0), 1, 8, 0);//根據初始點和結束點，將矩形畫到img上
		imshow("img", img);
		img.copyTo(tmp);
		//截取矩形包圍的圖像，並保存到dst中
		int width = abs(pre_pt.x - cur_pt.x);
		int height = abs(pre_pt.y - cur_pt.y);
		if (width == 0 || height == 0)
		{
			printf("width == 0 || height == 0");
			return;
		}
		dst = org(Rect(min(cur_pt.x, pre_pt.x), min(cur_pt.y, pre_pt.y), width, height));
		if (!first)
		{
			model = dst;
			first = true;
			imshow("model", model);
		}
		else
		{
			double distence = GetMatchVal(model, dst);
			printf("與第1次選定的圖像區域相似度爲：%f\n", distence);//越大，相似度越大
		}
		namedWindow("dst");
		imshow("dst", dst);
		waitKey(0);
	}
}
void main()
{
	string name = "./image/1.png";
	org = imread(name, 0);
	org.copyTo(img);
	org.copyTo(tmp);
	namedWindow("img");//定義一個img窗口
	setMouseCallback("img", on_mouse, 0);//調用回調函數
	imshow("img", img);
	cv::waitKey(0);
}