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@file SURF_FlannMatcher and OpenCV 3.0.0 do not link

asked 2016-01-18 10:34:47 -0500

ForestMan gravatar image

Hi I am relatively new to OpenCV. I program C++ in Vis Studio 2013 and use Cuda 6.5. I found FlannMatcher algorithm as presented on OpenCV as a good tool for parts of what I need to do. It took me 3 days to find out how to correct the program found on opencv.org so I could compile it under 3.0.0. Thanks to all of you who contribute with good answers to many peoples questions. Why isn't this good example updated? Now I can compile it, but the linker do not work. One 'specialist' advised to recompile opencv using the additions from opencv_contrib-master. I started this process going through the tutorial on opencv.org. I have come to the part where I shall install Numpy under Python. According to opencv.org I will need this to be able to read the documentation. It crashes all the time and I receive many different error messages that I find many others do as well.

Is there a simpler way to recompile opencv so the new Flannmatcher can link? or do anyone have the binaries needed so I do not need to recompile myself? I would appreciate all the help I can get here!

The changes in the program is that extractor and detector have become pointers and minHessian is double.

Ptr<SURF> detector = SURF::create(minHessian);
    std::vector<KeyPoint> keypts;
    Mat desc;
    //detector->detectAndCompute(img_1, noArray(), keypts, desc);

    std::vector<KeyPoint> keypoints_1, keypoints_2;
    detector->detectAndCompute(img_1, noArray(), keypoints_1, desc);
    detector->detectAndCompute(img_2, noArray(), keypoints_2, desc);

//SurfDescriptorExtractor extractor;
Ptr<SurfFeatureDetector>  extractor = SurfFeatureDetector::create(minHessian);
Mat descriptors_1, descriptors_2;
extractor->compute(img_1, keypoints_1, descriptors_1);
extractor->compute(img_2, keypoints_2, descriptors_2);

Listing of the new code

 // ConsoleApplication1.cpp : Defines the entry point for the console application.
//

/**
* @file SURF_FlannMatcher
* @brief SURF detector + descriptor + FLANN Matcher
* @author A. Huaman
*/
#define _CRT_SECURE_NO_DEPRECATE
#pragma warning (disable : 4996)
#include "stdafx.h"
#include <stdio.h>
#include <iostream>
#include <stdio.h>
#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/features2d.hpp"
//#include "D:\OpenCV\sources\modules\features2d\include\opencv2/features2d.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "D:\OpenCV\opencv_contrib-master\modules\xfeatures2d\include\opencv2/xfeatures2d.hpp"
#include "D:\OpenCV\opencv_contrib-master\modules\xfeatures2d\include\opencv2\xfeatures2d\nonfree.hpp"

using namespace std;
using namespace cv;
using namespace cv::xfeatures2d;

void readme();

/* * @function main * @brief Main function */ int main(int argc, char* argv) { if (argc != 3) { readme(); return -1; }

Mat img_1 = imread(argv[1], IMREAD_GRAYSCALE);
Mat img_2 = imread(argv[2], IMREAD_GRAYSCALE);

if (!img_1.data || !img_2.data)
{
    std::cout << " --(!) Error reading images " << std::endl; return -1;
}

using namespace cv::xfeatures2d;

//Ptr<SIFT> sift = SIFT::create(...);
//-- Step 1: Detect the keypoints using SURF Detector
//int minHessian = 400;
double minHessian = 400.0;

//SurfFeatureDetector detector(minHessian);
//Ptr<SurfFeatureDetector> detector = SurfFeatureDetector::create(minHessian, 4, 3, 0, 0);

Ptr<SURF> detector = SURF::create(minHessian);
std::vector<KeyPoint> keypts;
Mat desc;
//detector->detectAndCompute(img_1, noArray(), keypts, desc);

std::vector<KeyPoint> keypoints_1, keypoints_2;
detector->detectAndCompute(img_1, noArray(), keypoints_1, desc);
detector->detectAndCompute(img_2, noArray(), keypoints_2, desc);


//detector->detect ...
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answered 2016-01-25 08:13:57 -0500

dpwicaksa gravatar image

I've also experiencing problem when i used ORB with FlannBasedMatcher on OpenCV3, the problem is, Mat type used in Flann. Maybe you can try add this before declaring your FlannBasedMatcher

if(descriptor.type()!=CV_32F)
descriptor.convertTo(descriptor, CV_32F);

it solved my problem

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Comments

For binary descriptors like ORB, you have to use FLANN and LSH index. Converting to float number should produce some distance errors.

Some links:

Eduardo gravatar imageEduardo ( 2016-01-25 09:42:24 -0500 )edit
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Asked: 2016-01-18 10:34:47 -0500

Seen: 272 times

Last updated: Jan 25 '16