学习opencv有感（二）-2维特征Feature2D

/*在提取surf特征时，从官方文档复制过来的代码，编译报错。查了下是包含文件问题，SurfFeatureDetector在#include <opencv2/nonfree/features2d.hpp>文件中，以前版本是在#include "opencv2/features2d/features2d.hpp"中，SurfDescriptorExtractor在#include<opencv2/legacy/legacy.hpp>中，所以要包含那两个文件。代码如下：/**

* @file SURF_descriptor

* @brief SURF detector + descritpor + BruteForce Matcher + drawing matches with OpenCV functions

* @author A. Huaman

*/

#include <stdio.h>
#include <iostream>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <opencv2/nonfree/features2d.hpp>
#include<opencv2/legacy/legacy.hpp>
using namespace cv;

void readme();

/**
* @function main
* @brief Main function
*/
int main(  )
{
Mat img_1 = imread( "1.jpg", CV_LOAD_IMAGE_GRAYSCALE );
Mat img_2 = imread( "2.jpg", CV_LOAD_IMAGE_GRAYSCALE );

if( !img_1.data || !img_2.data )
{ return -1; }

//-- Step 1: Detect the keypoints using SURF Detector
int minHessian = 400;

SurfFeatureDetector detector( minHessian );

std::vector<KeyPoint> keypoints_1, keypoints_2;
detector.detect( img_1, keypoints_1 );
detector.detect( img_2, keypoints_2 );
//-- Step 2: Calculate descriptors (feature vectors)
SurfDescriptorExtractor extractor;
Mat descriptors_1, descriptors_2;
extractor.compute( img_1, keypoints_1, descriptors_1 );
extractor.compute( img_2, keypoints_2, descriptors_2 );
//-- Step 3: Matching descriptor vectors with a brute force matcher
BruteForceMatcher< L2<float> > matcher;
std::vector< DMatch > matches;
matcher.match( descriptors_1, descriptors_2, matches );
//-- Draw matches
Mat img_matches;
drawMatches( img_1, keypoints_1, img_2, keypoints_2, matches, img_matches );
//-- Show detected matches
imshow("Matches", img_matches );
waitKey(0);
return 0;
}