Opencv2.4.3 representation of Feature Extraction

1. Use a custom class implementation form

Another way to get brisk in opencv 2.4.3

Include header file "opencv2/features2d/features2d. HPP" where brisk class is implemented

// Read some images in gray scale

const char * PimA="box.png";   // objectconst char * PimB="box_in_scene.png"; // imagecv::Mat GrayA =cv::imread(PimA);cv::Mat GrayB =cv::imread(PimB);std::vector<cv::KeyPoint> keypointsA, keypointsB;cv::Mat descriptorsA, descriptorsB;

// Set brisk Parameters

int Threshl=60;int Octaves=4; (pyramid layer) from which the keypoint has been extractedfloat PatternScales=1.0f;

// Declare a variable briskd of the type CV: Brisk

cv::BRISK  BRISKD(Threshl,Octaves,PatternScales);//initialize algoritmBRISKD.create("Feature2D.BRISK");BRISKD.detect(GrayA, keypointsA);BRISKD.compute(GrayA, keypointsA,descriptorsA);BRISKD.detect(GrayB, keypointsB);BRISKD.compute(GrayB, keypointsB,descriptorsB);

Declare one type off matcher

cv::BruteForceMatcher<cv::Hamming> matcher;

Another match that can be used

//cv::FlannBasedMatcher matcher(new cv::flann::LshIndexParams(20,10,2)); std::vector<cv::DMatch> matches; matcher.match(descriptorsA, descriptorsB, matches);    cv::Mat all_matches;    cv::drawMatches( GrayA, keypointsA, GrayB, keypointsB,                         matches, all_matches, cv::Scalar::all(-1), cv::Scalar::all(-1),                         vector<char>(),cv::DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );    cv::imshow( "BRISK All Matches", all_matches );    cv::waitKey(0);    IplImage* outrecog = new IplImage(all_matches);    cvSaveImage( "BRISK All Matches.jpeg", outrecog );

2. Use common interfaces

cv::Ptr<cv::FeatureDetector> detector = cv::Algorithm::create<cv::FeatureDetector>("Feature2D.BRISK");detector->detect(GrayA, keypointsA);detector->detect(GrayB, keypointsB);cv::Ptr<cv::DescriptorExtractor> descriptorExtractor =cv::Algorithm::create<cv::DescriptorExtractor>("Feature2D.BRISK");descriptorExtractor->compute(GrayA, keypointsA, descriptorsA);descriptorExtractor->compute(GrayB, keypointsB, descriptorsB);