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OpenCV官方文档学习记录（1）
图像显示并转化为黑白输出到新文件
code：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 #pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 int main()11 {12 Mat img = imread("test.jpg",1);13 if (img.empty())14 {15 return -1;16 }17 Mat gray_img;18 cvtColor(img, gray_img, CV_BGR2GRAY);19 imwrite("./black.jpg", gray_img);20 21 namedWindow("Source", CV_WINDOW_AUTOSIZE);22 imshow("Source", img);23 namedWindow("Black", CV_WINDOW_AUTOSIZE);24 imshow("Black", gray_img);25 26 waitKey();27 return 0;28 }
结果：
Mat数据结构：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 #pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat A, C;19 A = imread("test.jpg", 1);20 Mat B(A);21 C = A;22 Mat D(A, Rect(10, 10, 100, 100));23 Mat E = A(Range::all(), Range(1, 3));24 Show("A", A);25 Show("B", B);26 Show("C", C);27 Show("D", D);28 Show("E", E);29 waitKey();30 return 0;31 }
结果：
以上显示的是浅拷贝，就是除了headers不同之外，其余的数据都是从一块数据块中取得的。
要实现深拷贝：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 #pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat img = imread("test.jpg", 1);19 Show("Source", img);20 Mat dest = img.clone();21 Show("Dest", dest);22 waitKey();23 return 0;24 }
或是：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 #pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat img = imread("test.jpg", 1);19 Show("Source", img);20 Mat dest;21 img.copyTo(dest);22 Show("Dest", dest);23 waitKey();24 return 0;25 }
构建Mat对象：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat M(2, 2, CV_8UC3, Scalar(0, 0, 255));19 cout << "M=" << endl << "" << M << endl << endl;20 system("pause");21 return 0;22 }
构造器参数，行+列+图像类型+填充数据。
模仿MatLab的函数：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat E = Mat::eye(4, 4, CV_64F);19 cout << E << endl;20 Mat O = Mat::ones(2, 2, CV_32F);21 cout << O << endl;22 Mat Z = Mat::zeros(3, 3, CV_8UC1);23 cout << Z << endl;24 system("pause");25 return 0;26 }
因为默认重载了流运算符，因此可以直接输出；
对于小矩阵使用逗号初始化：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat C = (Mat_<double>(3, 3) << 0, -1, 0, -1, 5, -1, 0, -1, 0);19 cout << C << endl;20 system("pause");21 return 0;22 }
可以按行列复制图像的色值：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat C = (Mat_<double>(3, 3) << 0, -1, 0, -1, 5, -1, 0, -1, 0);19 Mat Row = C.col(1).clone();20 cout << Row << endl;21 system("pause");22 return 0;23 }
随机生成矩阵方式：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 #pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat img;19 img = Mat(400, 400, CV_8UC3);20 randu(img, Scalar::all(0), Scalar::all(255));21 Show("Img", img);22 waitKey();23 return 0;24 }
randu后两个参数是取值范围；
矩阵值的输出格式：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Mat img;19 img = Mat(4, 4, CV_8UC3,Scalar::all(25));20 cout << img << endl;21 cout << format(img, "python") << endl;22 cout << format(img, "csv") << endl;23 cout << format(img, "numpy") << endl;24 cout << format(img, "C") << endl;25 system("pause");26 return 0;27 }
其他可以直接用流输出的数据类型是
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 5 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 6 7 using namespace std; 8 using namespace cv; 9 10 void Show(std::string name,Mat img)11 {12 namedWindow(name, CV_WINDOW_AUTOSIZE);13 imshow(name, img);14 }15 16 int main()17 {18 Point2f p2(5, 1);19 cout << p2 << endl;20 Point3f p3(2, 6, 7);21 cout << p3 << endl;22 vector<float> v;23 v.push_back((float)CV_PI);24 v.push_back(2);25 v.push_back(3.01f);26 cout << Mat(v) << endl;27 vector<Point2f> vPoints(20);28 for (size_t i = 0; i < vPoints.size(); ++i)29 vPoints[i] = Point2f((float)(i * 5), (float)(i % 7));30 cout << vPoints << endl;31 system("pause");32 return 0;33 }
计算算法运行时间：
1 #include <opencv2\opencv.hpp> 2 #include <iostream> 3 #include <string> 4 #include <sstream> 5 6 //#pragma comment( linker, "/subsystem:\"windows\" /entry:\"mainCRTStartup\"" ) 7 8 using namespace std; 9 using namespace cv;10 11 void Show(std::string name,Mat img)12 {13 namedWindow(name, CV_WINDOW_AUTOSIZE);14 imshow(name, img);15 }16 17 int main()18 {19 double t = getTickCount();20 //do somethings21 t = ((double)getTickCount() - t) / getTickFrequency();22 cout << t << endl;23 system("pause");24 return 0;25 }
下篇待续。。。
以上。
OpenCV官方文档学习记录（1）
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