opencv2.4.3特征提取的实现表示方法

1.采用自定义的类实现形式Another way to get brisk in OpenCV 2.4.3include header file "opencv2/features2d/features2d.hpp" where brisk class is implemented//read some images in gray scale

const char * PimA="box.png";   // object
const char * PimB="box_in_scene.png"; // image

cv::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 extracted
float PatternScales=1.0f;

//declare a variable BRISKD of the type cv::BRISK

cv::BRISK  BRISKD(Threshl,Octaves,PatternScales);//initialize algoritm
BRISKD.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 use

//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.采用通用接口

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);