Mat是Opencv2里面主要的类。Mat的对象常常用来表示一副图像的信息。
Mat的基本操作十分简单，不多说了。下面这段代码能够读七八分明白，应该就算对Mat有大体了解。
1 /* For description look into the help() function. */ 2 3 #include "opencv2/core/core.hpp" 4 #include <iostream> 5 6 using namespace std; 7 using namespace cv; 8 9 static void help() 10 { 11 cout 12 << "\n--------------------------------------------------------------------------" << endl 13 << "This program shows how to create matrices(cv::Mat) in OpenCV and its serial" 14 << " out capabilities" << endl 15 << "That is, cv::Mat M(...); M.create and cout << M. " << endl 16 << "Shows how output can be formated to OpenCV, python, numpy, csv and C styles." << endl 17 << "Usage:" << endl 18 << "./cvout_sample" << endl 19 << "--------------------------------------------------------------------------" << endl 20 << endl; 21 } 22 23 int main(int,char**) 24 { 25 help(); 26 // create by using the constructor 27 Mat M(2,2, CV_8UC3, Scalar(0,0,255)); 28 cout << "M = " << endl << " " << M << endl << endl; 29 30 // create by using the create function() 31 M.create(4,4, CV_8UC(2)); 32 cout << "M = "<< endl << " " << M << endl << endl; 33 34 // create multidimensional matrices 35 int sz[3] = {2,2,2}; 36 Mat L(3,sz, CV_8UC(1), Scalar::all(0)); 37 // Cannot print via operator << 38 39 // Create using MATLAB style eye, ones or zero matrix 40 Mat E = Mat::eye(4, 4, CV_64F); 41 cout << "E = " << endl << " " << E << endl << endl; 42 43 Mat O = Mat::ones(2, 2, CV_32F); 44 cout << "O = " << endl << " " << O << endl << endl; 45 46 Mat Z = Mat::zeros(3,3, CV_8UC1); 47 cout << "Z = " << endl << " " << Z << endl << endl; 48 49 // create a 3x3 double-precision identity matrix 50 Mat C = (Mat_<double>(3,3) << 0, -1, 0, -1, 5, -1, 0, -1, 0); 51 cout << "C = " << endl << " " << C << endl << endl; 52 53 Mat RowClone = C.row(1).clone(); 54 cout << "RowClone = " << endl << " " << RowClone << endl << endl; 55 56 // Fill a matrix with random values 57 Mat R = Mat(3, 2, CV_8UC3); 58 randu(R, Scalar::all(0), Scalar::all(255)); 59 60 // Demonstrate the output formating options 61 cout << "R (default) = " << endl << R << endl << endl; 62 cout << "R (python) = " << endl << format(R,"python") << endl << endl; 63 cout << "R (numpy) = " << endl << format(R,"numpy" ) << endl << endl; 64 cout << "R (csv) = " << endl << format(R,"csv" ) << endl << endl; 65 cout << "R (c) = " << endl << format(R,"C" ) << endl << endl; 66 67 Point2f P(5, 1); 68 cout << "Point (2D) = " << P << endl << endl; 69 70 Point3f P3f(2, 6, 7); 71 cout << "Point (3D) = " << P3f << endl << endl; 72 73 74 vector<float> v; 75 v.push_back( (float)CV_PI); v.push_back(2); v.push_back(3.01f); 76 77 cout << "Vector of floats via Mat = " << Mat(v) << endl << endl; 78 79 vector<Point2f> vPoints(20); 80 for (size_t i = 0; i < vPoints.size(); ++i) 81 vPoints[i] = Point2f((float)(i * 5), (float)(i % 7)); 82 83 cout << "A vector of 2D Points = " << vPoints << endl << endl; 84 return 0; 85 }