CODEWITHSUNDEEP
opencvfeature-extraction
sy456
sy456

Reputation: 1704

opencv sample doesn't work (detectors_descriptors_evaluation.cpp)

I want to run detector_descriptor_evaluation.cpp sample in OpenCV with opencv_extra dataset. However, I get errors about SIFT, SURF detector and I cannot use matchers. I wonder if somebody had these problems that i am going to explain.

The main function creates an object of DetectorQualityEvaluator class with different detector and/or matcher types as shown below:

Ptr<BaseQualityEvaluator> evals[] =
{
    new DetectorQualityEvaluator( "FAST", "quality-detector-fast" ),
    new DetectorQualityEvaluator( "GFTT", "quality-detector-gftt" ),
    new DetectorQualityEvaluator( "HARRIS", "quality-detector-harris" ),
    new DetectorQualityEvaluator( "MSER", "quality-detector-mser" ),
    new DetectorQualityEvaluator( "STAR", "quality-detector-star" ),
    new DetectorQualityEvaluator( "SIFT", "quality-detector-sift" ),
    new DetectorQualityEvaluator( "SURF", "quality-detector-surf" ),
    new DescriptorQualityEvaluator( "SIFT", "quality-descriptor-sift", "BruteForce" ),
    new DescriptorQualityEvaluator( "SURF", "quality-descriptor-surf", "BruteForce" ),
    new DescriptorQualityEvaluator( "FERN", "quality-descriptor-fern"),
    new CalonderDescriptorQualityEvaluator()
};

Program works fine until SIFT and SURF detectors but it gives "Algorithm cannot be read" error. In other words, I cannot create these detectors. When I don't create SIFT and SURF detectors 

    //new DetectorQualityEvaluator( "SIFT", "quality-detector-sift" ),
    //new DetectorQualityEvaluator( "SURF", "quality-detector-surf" ),

I get the following error:

   OpenCV Error: Assertion failed (!extractor.empty() && !matcher.empty()) in VectorDescriptorMatcher, file /home/sy/opencv-2.4.8/modules/features2d/src/matchers.cpp, line 1089

When I use following code

    //new DetectorQualityEvaluator( "SIFT", "quality-detector-sift" ),
    //new DetectorQualityEvaluator( "SURF", "quality-detector-surf" ),
    //new DescriptorQualityEvaluator( "SIFT", "quality-descriptor-sift", "BruteForce" ),
    //new DescriptorQualityEvaluator( "SURF", "quality-descriptor-surf", "BruteForce" ),
    new DescriptorQualityEvaluator( "FERN", "quality-descriptor-fern"),
    new CalonderDescriptorQualityEvaluator()

I also get the errro below. I think it doesn't recognize "FERN" matcher. Only CalonderDescriptor works in this example.

  OpenCV Error: Bad argument (Unknown matcher name) in create, file /home/sy/opencv-2.4.8/modules/features2d/src/matchers.cpp, line 488

Regards

Upvotes: 0

Views: 772

Answers (1)

user3338932
user3338932

Reputation: 21

I encountered the exact same failure. After some debugging I found that for SIFT and SURF, you'll need the nonfree module, which is missing from the example code. Add :

#include "opencv2/nonfree/nonfree.hpp"

Then insert the following in main():

cv::initModule_nonfree();

before the line:

Ptr<BaseQualityEvaluator> evals[] =

Regards

Upvotes: 2

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