OpenCV image matching algorithm-sift, opencv image sift

OpenCV image matching algorithm-sift, opencv image sift

//utils.h#ifndef _UTILS_H#define _UTILS_H#include <opencv2/opencv.hpp>#include <opencv2/features2d/features2d.hpp>#include <opencv2/core/core.hpp>#include <opencv2/imgproc/imgproc.hpp>#include <opencv2\nonfree\nonfree.hpp>using namespace cv;// ORB settingsconst int ORB_MAX_KPTS = 1500;const float ORB_SCALE_FACTOR = 1.5;const int ORB_PYRAMID_LEVELS = 3;const float ORB_EDGE_THRESHOLD = 31.0;const int ORB_FIRST_PYRAMID_LEVEL = 0;const int ORB_WTA_K = 2;const int ORB_PATCH_SIZE = 31;// BRISK settingsconst float BRISK_HTHRES = 10.0;const int BRISK_NOCTAVES = 6;const float DRATIO = 0.8f;// NNDR Matching valueconst float MIN_H_ERROR = 2.50f;// Maximum error in pixels to accept an inliervoid matches2points_nndr(const std::vector<cv::KeyPoint>& train,                         const std::vector<cv::KeyPoint>& query,                         const std::vector<std::vector<cv::DMatch> >& matches,                         std::vector<cv::Point2f>& pmatches, float nndr);void compute_inliers_ransac(const std::vector<cv::Point2f>& matches,                            std::vector<cv::Point2f>& inliers,                            float error, bool use_fund);void draw_inliers(const cv::Mat& img1, const cv::Mat& img2, cv::Mat& img_com,                  const std::vector<cv::Point2f>& ptpairs, int color);typedef struct info{double t;int n1;int n2;int m;int rm;}INFO;void sift(char* path1, char* path2, INFO& info, bool show);void surf(char* path1, char* path2, INFO& info, bool show);void orb(char* path1, char* path2, INFO& info, bool show);void brisk(char* path1, char* path2, INFO& info, bool show);void freak(char* path1, char* path2, INFO& info, bool show);void showInfo(INFO info);#endif

//utils.cpp#include "stdafx.h"#include "utils.h"#include <iostream>using namespace std;/** * @brief This function converts matches to points using nearest neighbor distance * ratio matching strategy * @param train Vector of keypoints from the first image * @param query Vector of keypoints from the second image * @param matches Vector of nearest neighbors for each keypoint * @param pmatches Vector of putative matches * @param nndr Nearest neighbor distance ratio value */void matches2points_nndr(const std::vector<cv::KeyPoint>& train,                         const std::vector<cv::KeyPoint>& query,                         const std::vector<std::vector<cv::DMatch> >& matches,                         std::vector<cv::Point2f>& pmatches, float nndr) {  float dist1 = 0.0, dist2 = 0.0;  for (size_t i = 0; i < matches.size(); i++) {    DMatch dmatch = matches[i][0];    dist1 = matches[i][0].distance;    dist2 = matches[i][1].distance;    if (dist1 < nndr*dist2) {      pmatches.push_back(train[dmatch.queryIdx].pt);      pmatches.push_back(query[dmatch.trainIdx].pt);    }  }}/** * @brief This function computes the set of inliers estimating the fundamental matrix * or a planar homography in a RANSAC procedure * @param matches Vector of putative matches * @param inliers Vector of inliers * @param error The minimum pixelic error to accept an inlier * @param use_fund Set to true if you want to compute a fundamental matrix */void compute_inliers_ransac(const std::vector<cv::Point2f>& matches,                            std::vector<cv::Point2f>& inliers,                            float error, bool use_fund) {  vector<Point2f> points1, points2;  Mat H = Mat::zeros(3,3,CV_32F);  int npoints = matches.size()/2;  Mat status = Mat::zeros(npoints,1,CV_8UC1);  for (size_t i = 0; i < matches.size(); i+=2) {    points1.push_back(matches[i]);    points2.push_back(matches[i+1]);  }  if (use_fund == true){    H = findFundamentalMat(points1,points2,CV_FM_RANSAC,error,0.99,status);  }  else {    H = findHomography(points1,points2,CV_RANSAC,error,status);  }  for (int i = 0; i < npoints; i++) {    if (status.at<unsigned char>(i) == 1) {      inliers.push_back(points1[i]);      inliers.push_back(points2[i]);    }  }}//*******************************************************************************//*******************************************************************************/** * @brief This function draws the set of the inliers between the two images * @param img1 First image * @param img2 Second image * @param img_com Image with the inliers * @param ptpairs Vector of point pairs with the set of inliers * @param color The color for each method */void draw_inliers(const cv::Mat& img1, const cv::Mat& img2, cv::Mat& img_com,                  const std::vector<cv::Point2f>& ptpairs, int color) {  int x1 = 0, y1 = 0, x2 = 0, y2 = 0;  float rows1 = 0.0, cols1 = 0.0;  float rows2 = 0.0, cols2 = 0.0;  float ufactor = 0.0, vfactor = 0.0;  rows1 = img1.rows;  cols1 = img1.cols;  rows2 = img2.rows;  cols2 = img2.cols;  ufactor = (float)(cols1)/(float)(cols2);  vfactor = (float)(rows1)/(float)(rows2);  // This is in case the input images don't have the same resolution  Mat img_aux = Mat(Size(img1.cols,img1.rows),CV_8UC3);  resize(img2,img_aux,Size(img1.cols,img1.rows),0,0,CV_INTER_LINEAR);  for (int i = 0; i < img_com.rows; i++) {    for (int j = 0; j < img_com.cols; j++) {      if (j < img1.cols) {        *(img_com.ptr<unsigned char>(i)+3*j) = *(img1.ptr<unsigned char>(i)+3*j);        *(img_com.ptr<unsigned char>(i)+3*j+1) = *(img1.ptr<unsigned char>(i)+3*j+1);        *(img_com.ptr<unsigned char>(i)+3*j+2) = *(img1.ptr<unsigned char>(i)+3*j+2);      }      else {        *(img_com.ptr<unsigned char>(i)+3*j) = *(img_aux.ptr<unsigned char>(i)+3*(j-img_aux.cols));        *(img_com.ptr<unsigned char>(i)+3*j+1) = *(img_aux.ptr<unsigned char>(i)+3*(j-img_aux.cols)+1);        *(img_com.ptr<unsigned char>(i)+3*j+2) = *(img_aux.ptr<unsigned char>(i)+3*(j-img_aux.cols)+2);      }    }  }  for (size_t i = 0; i < ptpairs.size(); i+= 2) {    x1 = (int)(ptpairs[i].x+.5);    y1 = (int)(ptpairs[i].y+.5);    x2 = (int)(ptpairs[i+1].x*ufactor+img1.cols+.5);    y2 = (int)(ptpairs[i+1].y*vfactor+.5);    if (color == 0) {      line(img_com,Point(x1,y1),Point(x2,y2),CV_RGB(255,255,0),1);    }    else if (color == 1) {      line(img_com,Point(x1,y1),Point(x2,y2),CV_RGB(255,0,0),1);    }    else if (color == 2) {      line(img_com,Point(x1,y1),Point(x2,y2),CV_RGB(0,0,255),1);    }  }}void showInfo(INFO info){printf("%-40s%d\n","The keypoints number of src image is :", info.n1);printf("%-40s%d\n","The keypoints number of dst image is : ", info.n2);printf("%-40s%d\n","The matching number is : ", info.m);printf("%-40s%d\n","The right result number is : ", info.rm);printf("%-40s%.2fs\n","The total time is : ", info.t);return ;}

// Sift. cpp # include "stdafx. h "# include <cv. hpp> # include 
Use

INFO sift_info;sift(path1,path2,sift_info,true);showInfo(sift_info);