Question

我在处理OpenCV / C++项目时遇到了一个奇怪的问题。我只是想在KNN课程中使用ClassifierManager。出于这个原因，我正在使用cv::flann::Index * knnFlan，它在构造函数中初始化，如下所示：

·H

class ClassifierManager
{
private:
    Mat dataToTrain;
    Mat classesData;
    int kNearestNeighborToConsider;
    CvKNearest *classifier;
    cv::flann::Index *knnFlan;

public:
    ClassifierManager();
    ClassifierManager(Mat trainData, Mat dataClasses, int numberOfNearestNeighborToConsider);
    vector < vector <int> > annotateTheTilesInImages(Mat trainData, vector < vector < vector <double> > > featuresPerImageForTiles, int numberOfNearestNeighborToConsider);
};

的.m

ClassifierManager::ClassifierManager()
{}

ClassifierManager::ClassifierManager(Mat trainData, Mat dataClasses, int numberOfNearestNeighborToConsider)
{
//    dataToTrain = trainData;
//    classesData = dataClasses;
    kNearestNeighborToConsider = numberOfNearestNeighborToConsider;
    try
    {
        dataClasses.convertTo(dataClasses,CV_32FC1);
        trainData.convertTo(trainData,CV_32FC1);
        knnFlan = new flann::Index( trainData, flann::KDTreeIndexParams(1), cvflann::FLANN_DIST_EUCLIDEAN);
    } catch (std::exception& ex)
    {
        cout << ex.what() << endl;
    }
}

vector < vector <int> > ClassifierManager::annotateTheTilesInImages( vector < vector < vector <double> > > featuresPerImageForTiles, int numberOfNearestNeighborToConsider)
{
    vector < vector <int> > resultForImagePerTile;
    for (int imageIndex = 0; imageIndex < featuresPerImageForTiles.size(); imageIndex++ )
    {
        vector < vector <double> >featuresPerTile = featuresPerImageForTiles[imageIndex];
        vector <int>  resultPerTile;
        for (int tileIndex = 0; tileIndex < featuresPerTile.size(); tileIndex ++)
        {
            vector <double> featureForTile = featuresPerTile[tileIndex];

            // estimate the response and get the neighbors' labels
            cv::Mat results, dists;
            Mat featureOfTileInMat(featureForTile);
            featureOfTileInMat.convertTo(featureOfTileInMat, CV_32FC1);
            featureOfTileInMat = featureOfTileInMat.t();
            //int result = classifier->find_nearest(featureOfTileInMat,numberOfNearestNeighborToConsider, &results, 0, &neighborResponses, &dists);
            //float percentageOfInstrumentForThisWindow = (float(countNonZero(neighborResponses)) / numberOfNearestNeighborToConsider) * 100;

            knnFlan->knnSearch(featureOfTileInMat, results, dists, numberOfNearestNeighborToConsider, flann::SearchParams());

              //..... Things to add


        }
    }

    return resultForImagePerTile;
}

的main.m

/*Step 9: Knn Classifier train data */
Mat trainData = VectorUtility <double>::toMat(featuresPerTile);
Mat dataClasses = VectorUtility <int>::toMat(annotationPerTile);
ClassifierManager classifier(trainData, dataClasses, kNearestNeighbor);

/*Step 10: Annotation Step*/
vector < vector <int> > resultsForEachImagePerTile = classifier.annotateTheTilesInImages(trainData, featuresPerImageForTiles, kNearestNeighbor);

问题是，当我尝试annotateTheTilesInImages main knnFlan->knnSearch(featureOfTileInMat, results, dists, numberOfNearestNeighborToConsider, flann::SearchParams());项目崩溃segmentation fault时，通过投掷class ClassifierManager { private: Mat dataToTrain; Mat classesData; int kNearestNeighborToConsider; CvKNearest *classifier; cv::flann::Index *knnFlan; public: ClassifierManager(); ClassifierManager(Mat &trainData, Mat &dataClasses, int numberOfNearestNeighborToConsider); vector < vector <int> > annotateTheTilesInImages(Mat trainData, vector < vector < vector <double> > > featuresPerImageForTiles, int numberOfNearestNeighborToConsider); };无法通过尝试抓住ClassifierManager::ClassifierManager() {} ClassifierManager::ClassifierManager(Mat &trainData, Mat &dataClasses, int numberOfNearestNeighborToConsider) { dataToTrain = trainData; classesData = dataClasses; kNearestNeighborToConsider = numberOfNearestNeighborToConsider; try { dataToTrain .convertTo(dataToTrain ,CV_32FC1); knnFlan = new flann::Index( dataToTrain , flann::KDTreeIndexParams(1), cvflann::FLANN_DIST_EUCLIDEAN); } catch (std::exception& ex) { cout << ex.what() << endl; } } ....抓住指示。在我看来，如何管理类中的实例变量存在问题，但不确定它是什么！任何帮助表示赞赏。

@updated 只删除不必要的代码

@Edited：正确的代码：

·H

[1, 0, 0]

的.m

sin(90) = 1

Answer 1

代码中还有一些问题（例如，我没有看到CvKNearest *classifier初始化的任何地方），但我认为您的问题是由以下原因引起的：

您通过值将trainData传递给annotateTheTilesInImages，而不是引用或常量引用。这意味着此函数中的trainData是另一个对象（当然具有相同的数据 - OpenCV 支持隐式共享），但对于flann::Index这可能是一个问题。

编辑：对不起，我的意思是您将值矩阵传递给ClassifierManager构造函数，而不仅仅是annotateTheTilesInImages。 I. e。传递给cv::Mat构造函数的flann::Index对象在ClassifierManager构造函数之外不存在（尽管数据仍由其他cv::Mat对象处理）。

访问私有实例变量c ++

1 个答案: