【OpenCV学习笔记】二十三、模板匹配及应用

模板匹配及应用

1.模版匹配——matchTemplate()

2.实现了几个小应用：图像单目标模板匹配、视频单目标模板匹配、多目标模板匹配

先上ppt：













代码：

1.图像单目标模板匹配

///图像单目标模板匹配
#include "opencv2/opencv.hpp"
using namespace cv;
#include <iostream>
using namespace std;
int main()
{
Mat srcImg = imread("j.jpg",CV_LOAD_IMAGE_COLOR);
Mat tempImg = imread("template.jpg",CV_LOAD_IMAGE_COLOR);
cout << "Size of template: "<<tempImg.size() << endl;
//1.构建结果图像resultImg(注意大小和类型)
//如果原图(待搜索图像)尺寸为W x H, 而模版尺寸为 w x h, 则结果图像尺寸一定是(W-w+1)x(H-h+1)
//结果图像必须为单通道32位浮点型图像
int width = srcImg.cols - tempImg.cols + 1;
int height = srcImg.rows - tempImg.rows + 1;
Mat resultImg(Size(width,height),CV_32FC1);
//2.模版匹配
matchTemplate(srcImg, tempImg, resultImg, CV_TM_CCOEFF_NORMED);
imshow("result",resultImg);
//3.正则化(归一化到0-1)
normalize(resultImg,resultImg,0,1,NORM_MINMAX,-1);
//4.找出resultImg中的最大值及其位置
double minValue = 0;
double maxValue = 0;
Point minPosition;
Point maxPosition;
minMaxLoc(resultImg,&minValue,&maxValue,&minPosition,&maxPosition);
cout << "minValue: " << minValue << endl;
cout << "maxValue: " << maxValue << endl;
cout << "minPosition: " << minPosition << endl;
cout << "maxPosition: " << maxPosition << endl;
//5.根据resultImg中的最大值位置在源图上画出矩形
rectangle(srcImg,maxPosition,Point(maxPosition.x+tempImg.cols,maxPosition.y+tempImg.rows),Scalar(0,255,0),1,8);
imshow("srcImg", srcImg);
imshow("template", tempImg);
waitKey(0);
return 0;
}

运行结果：



2.视频单目标模板匹配

///视频单目标模板匹配
#include "opencv2/opencv.hpp"
using namespace cv;
#include <iostream>
using namespace std;
int main()
{
//1.定义VideoCapture类对象video，读取视频
VideoCapture video("1.mp4");
//1.1.判断视频是否打开
if (!video.isOpened())
{
cout << "video open error!" << endl;
return 0;
}
//2.循环读取视频的每一帧，对每一帧进行模版匹配
while (1)
{
//2.1.读取帧
Mat frame;
video >> frame;
//2.2.对帧进行异常检测
if (frame.empty())
{
cout << "frame empty" << endl;
break;
}
//2.3.对帧进行模版匹配
Mat tempImg = imread("green.JPG", CV_LOAD_IMAGE_COLOR);
cout << "Size of template: " << tempImg.size() << endl;
//2.3.1.构建结果图像resultImg(注意大小和类型)
//如果原图(待搜索图像)尺寸为W x H, 而模版尺寸为 w x h, 则结果图像尺寸一定是(W-w+1)x(H-h+1)
//结果图像必须为单通道32位浮点型图像
int width = frame.cols - tempImg.cols + 1;
int height = frame.rows - tempImg.rows + 1;
Mat resultImg(Size(width, height), CV_32FC1);
//2.3.2.模版匹配
matchTemplate(frame, tempImg, resultImg, CV_TM_CCOEFF_NORMED);
imshow("result", resultImg);
//2.3.3.正则化(归一化到0-1)
normalize(resultImg, resultImg, 0, 1, NORM_MINMAX, -1);
//2.3.4.找出resultImg中的最大值及其位置
double minValue = 0;
double maxValue = 0;
Point minPosition;
Point maxPosition;
minMaxLoc(resultImg, &minValue, &maxValue, &minPosition, &maxPosition);
cout << "minValue: " << minValue << endl;
cout << "maxValue: " << maxValue << endl;
cout << "minPosition: " << minPosition << endl;
cout << "maxPosition: " << maxPosition << endl;
//2.3.5.根据resultImg中的最大值位置在源图上画出矩形
rectangle(frame, maxPosition, Point(maxPosition.x + tempImg.cols, maxPosition.y + tempImg.rows), Scalar(0, 255, 0), 1, 8);
imshow("srcImg", frame);
imshow("template", tempImg);
if (waitKey(10) == 27)
{
cout << "ESC退出" << endl;
break;
};
}
return 0;
}

运行结果：



3.多目标模板匹配

///多目标模板匹配
#include "opencv2/opencv.hpp"
using namespace cv;
#include <iostream>
using namespace std;
int main()
{
Mat srcImg = imread("k.jpg", CV_LOAD_IMAGE_COLOR);
Mat tempImg = imread("template.jpg", CV_LOAD_IMAGE_COLOR);
//1.构建结果图像resultImg(注意大小和类型)
//如果原图(待搜索图像)尺寸为W x H, 而模版尺寸为 w x h, 则结果图像尺寸一定是(W-w+1)x(H-h+1)
//结果图像必须为单通道32位浮点型图像
int width = srcImg.cols - tempImg.cols + 1;
int height = srcImg.rows - tempImg.rows + 1;
Mat resultImg(Size(width, height), CV_32FC1);
//2.模版匹配
matchTemplate(srcImg, tempImg, resultImg, CV_TM_CCOEFF_NORMED);
imshow("result", resultImg);
//3.正则化(归一化到0-1)
normalize(resultImg, resultImg, 0, 1, NORM_MINMAX, -1);
//4.遍历resultImg，给定筛选条件，筛选出前几个匹配位置
int tempX = 0;
int tempY = 0;
char prob[10] = { 0 };
//4.1遍历resultImg
for (int i = 0 ; i<resultImg.rows;i++)
{
for (int j = 0; j<resultImg.cols; j++)
{
//4.2获得resultImg中(j,x)位置的匹配值matchValue
double matchValue = resultImg.at<float>(i, j);
sprintf(prob, "%.2f", matchValue);
//4.3给定筛选条件
//条件1:概率值大于0.9
//条件2:任何选中的点在x方向和y方向上都要比上一个点大5(避免画边框重影的情况)
if (matchValue > 0.9&& abs(i-tempY)>5&&abs(j-tempX)>5)
{
//5.给筛选出的点画出边框和文字
rectangle(srcImg, Point(j,i), Point(j + tempImg.cols, i + tempImg.rows), Scalar(0, 255, 0), 1, 8);
putText(srcImg, prob, Point(j, i+100),CV_FONT_BLACK,1,Scalar(0,0,255),1);
tempX = j;
tempY = i;
}
}
}
imshow("srcImg", srcImg);
imshow("template", tempImg);
waitKey(0);
return 0;
}

运行结果：