OpenCV SVM

 #include <opencv2/core/core.hpp>
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/ml/ml.hpp>  

 using namespace cv;

 int main()
 {
     // Data for visual representation
     int width = , height = ;
     Mat image = Mat::zeros(height, width, CV_8UC3);

     // Set up training data
     float labels[] = { 1.0, -1.0, -1.0, -1.0, 1.0 };
     Mat labelsMat(, , CV_32FC1, labels);

     float trainingData[][] = { { ,  }, { ,  }, { ,  }, { ,  }, { ,  } };
     Mat trainingDataMat(, , CV_32FC1, trainingData);

     //设置支持向量机的参数
     CvSVMParams params;
     params.svm_type = CvSVM::C_SVC;//SVM类型：使用C支持向量机
     params.kernel_type = CvSVM::LINEAR;//核函数类型：线性
     params.term_crit = cvTermCriteria(CV_TERMCRIT_ITER, , 1e-);//终止准则函数：当迭代次数达到最大值时终止  

     //训练SVM
     //建立一个SVM类的实例
     CvSVM SVM;
     //训练模型，参数为：输入数据、响应、XX、XX、参数（前面设置过）
     SVM.train(trainingDataMat, labelsMat, Mat(), Mat(), params);

     Vec3b green(, , ), blue(, , );
     //显示判决域
     for (int i = ; i < image.rows; ++i)
     for (int j = ; j < image.cols; ++j)
     {
         Mat sampleMat = (Mat_<float>(, ) << i, j);
         //predict是用来预测的，参数为：样本、返回值类型（如果值为ture而且是一个2类问题则返回判决函数值，否则返回类标签）、
         float response = SVM.predict(sampleMat);

         if (response == )
             image.at<Vec3b>(j, i) = green;
         else if (response == -)
             image.at<Vec3b>(j, i) = blue;
     }

     //画出训练数据
     int thickness = -;
     int lineType = ;
     circle(image, Point(, ), , Scalar(, , ), thickness, lineType);//画圆
     circle(image, Point(, ), , Scalar(, , ), thickness, lineType);
     circle(image, Point(, ), , Scalar(, , ), thickness, lineType);
     circle(image, Point(, ), , Scalar(, , ), thickness, lineType);
     circle(image, Point(, ), , Scalar(, , ), thickness, lineType);

     //显示支持向量
     thickness = ;
     lineType = ;
     //获取支持向量的个数
     int c = SVM.get_support_vector_count();

     for (int i = ; i < c; ++i)
     {
         //获取第i个支持向量
         const float* v = SVM.get_support_vector(i);
         //支持向量用到的样本点，用灰色进行标注
         circle(image, Point((int)v[], (int)v[]), , Scalar(, , ), thickness, lineType);
     }

     imwrite("result.png", image);        // save the image   

     imshow("SVM Simple Example", image); // show it to the user
     waitKey();

 }