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Feature Detection Interface vs Specific Classes

asked 2013-06-28 11:03:31 -0500

arablau gravatar image

Hi everyone,

I was wondering what the difference is between cv::FeatureDetector and specific classes like cv::SIFT.

If I create an instance of cv::SIFT as follows, my code works:

cv::SIFT sift;

// Detect key points and extract descriptors
std::cout << "Detecting key points" << std::endl;
sift(front, cv::Mat(), frontKeyPoints, frontDescriptors);

but if I try to use the cv::FeatureDetector::create my program crashes!

// Create SIFT feature detector    
siftDetector = cv::FeatureDetector::create("SIFT");

// Detect key points
std::cout << "Detecting key points" << std::endl;
siftDetector->detect(front, frontKeyPoints);

Why does the FeatureDetector crash? Is one better to use than the other?

Thanks

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answered 2013-06-28 11:31:07 -0500

BeS gravatar image

Can you write initModule_nonfree () before calling siftDetector = cv :: FeatureDetector :: create ("SIFT")? Probably cv :: FeatureDetector :: create ("SIFT") returns you to the null pointer. This occurs because the algorithm SIFT and SURF are outside module features2d.

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Thank you! Calling initModule_nonfree() worked!

arablau gravatar imagearablau ( 2013-06-28 15:45:16 -0500 )edit
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Asked: 2013-06-28 11:03:31 -0500

Seen: 121 times

Last updated: Jun 28 '13