Ask Your Question

Svistoplyas's profile - activity

2018-01-10 20:58:49 -0500 marked best answer Cluster crushes with unknown exception

Dear Community

I seek for your help. I found this project that builds Bag-of-Features Descriptor on SIFT Features on OpenCV 2.3. I will use OpenCV 3.4.0

I tried to rewrite first part of it to Java and there are two things that are not similar between his and my code. Firstly I chose only 3 images and he chose 20. Secondly I'm not sure that TermCriteria types in C++ and Java are similar.

He uses this


type. But I have only these types to choose

TermCriteria.EPS TermCriteria.COUNT TermCriteria.MAX_ITER

Here is my code

public static void main(String[] args) throws Exception{
    FeatureDetector detector = FeatureDetector.create(FeatureDetector.ORB);
    DescriptorExtractor descriptor = DescriptorExtractor.create(DescriptorExtractor.ORB);

    Mat img;
    MatOfKeyPoint keypoints = new MatOfKeyPoint();
    Mat desc = new Mat();
    Mat featuresUnclustered = new Mat();

    for(String file : filename){
        img = Imgcodecs.imread(file, Imgcodecs.CV_LOAD_IMAGE_GRAYSCALE);
        detector.detect(img, keypoints);
        descriptor.compute(img, keypoints, desc);

    //Construct BOWKMeansTrainer
    //the number of bags
    int dictionarySize=200;
    //define Term Criteria
    TermCriteria tc = new TermCriteria(TermCriteria.EPS | TermCriteria.MAX_ITER,100,0.001);
    //retries number
    int retries=1;
    //necessary flags
    int flags=Core.KMEANS_PP_CENTERS;
    //Create the BoW (or BoF) trainer
    BOWKMeansTrainer bowTrainer = new BOWKMeansTrainer(dictionarySize,tc,retries,flags);
    //cluster the feature vectors
    Mat dictionary=bowTrainer.cluster(featuresUnclustered);
    //store the vocabulary

And this is exception that i got

image description

Any information will be helpful

2018-01-10 20:58:49 -0500 received badge  Scholar (source)
2018-01-10 20:58:25 -0500 commented answer Cluster crushes with unknown exception

Thank you for answer. Firstly I've chosen SIFT descriptors and after that I changed it to SURF and ORB, because I thoug

2018-01-10 10:52:34 -0500 asked a question Cluster crushes with unknown exception

Cluster crushes with unknown exception Dear Community I seek for your help. I found this project that builds Bag-of-Fea