未在此范围内声明CvSVM错误

Question

I am using OpenCV 3.0.0

I have included all these libraries and namespaces,but I still get the error of "CvSVM is not declared in this scope"

#include <opencv2/core.hpp>
#include <opencv2/imgproc.hpp>
#include "opencv2/imgcodecs.hpp"
#include <opencv2/highgui.hpp>
#include <opencv2/ml.hpp>

using namespace cv;
using namespace cv::ml;
using namespace std;

When I run this code:

CvSVM svm;

I get the error.

Answer 1

In OpenCV 3.0 CvSVM has been renamed to SVM and moved to namespace cv::ml (actually also in previous version SVM was a typedef for CvSVM ).

Since SVM is an abstract class, you can't instantiate it. You need to call SVM::create() .

So you need to do:

cv::Ptr<cv::ml::SVM> svm = cv::ml::SVM::create();

or simply:

using namespace cv;
using namespace cv::ml;
...
Ptr<SVM> svm = SVM::create();

You don't need CvSVMParams anymore. Simply set the parameters directly to the svm :

Ptr<SVM> svm = SVM::create();
svm->setType(SVM::C_SVC);
svm->setKernel(SVM::RBF);
// etc