I use OpenCV 2.44 and Visual Studio C++ 2010
When I compile this
#include <opencv2/imgproc/imgproc_c.h>
#include <stdio.h>
#include <math.h>
#include <opencv/highgui.h>
#include <opencv/cv.h>
#include <opencv2/features2d/features2d.hpp>
#include <opencv2/calib3d/calib3d.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/nonfree/features2d.hpp>
#include <opencv2/legacy/legacy.hpp>
using namespace cv;
void main()
{
Mat img1 = imread( "hh.jpg", CV_LOAD_IMAGE_GRAYSCALE );
Mat img2 = imread( "hh.jpg", CV_LOAD_IMAGE_GRAYSCALE );
// detecting keypoints
FastFeatureDetector detector(15);
vector<KeyPoint> keypoints1;
detector.detect(img1, keypoints1);
// computing descriptors
SurfDescriptorExtractor extractor;
Mat descriptors1;
extractor.compute(img1, keypoints1, descriptors1);
when I run the code I get Unhandled exception at 0x580f375b in prj.exe: 0xC0000005: Access violation reading location 0x001f7014.
the error is at extractor
I'm using this tutorial link
It's looks like that you forget to init non-free module. Try to call appropriate function before using SurfDescriptorExtractor:
#include <opencv2/nonfree/nonfree.hpp>
...
cv::initModule_nonfree();
Related
I am trying to do a simple surf feature detection.
The problem is that during the execution I have two Microsoft Visual C++ Runtime Library Errors with only the use of the detect method :
Debug Assertion Failed ! Program:
C:\Windows\system32\MSVCP120D.dll File : C:\Program Files
(x86\Microsoft Visual Studio 12.0\VC\include\vector Line: 240
Expression : vector iterators incompatible
And
Debug Assertion Failed ! Program:
C:\opencv\build\x64\vc12\bin\Debug\opencv_xfeatures2d300d.dll File : C:\Program Files
(x86\Microsoft Visual Studio 12.0\VC\include\vector Line: 241
Expression : "Standard C++ Libraries Invalid Argument" && 0
This is the code :
#include "opencv2/core.hpp"
#include "opencv2/core/utility.hpp"
#include "opencv2/core/ocl.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/features2d.hpp"
#include "opencv2/calib3d.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/xfeatures2d.hpp"
#include "opencv/cv.h"
#include "opencv/highgui.h"
using namespace cv;
using namespace std;
using namespace xfeatures2d;
int main(int argc, const char** argv)
{
// Read image
Mat img1 = imread("box.png", CV_LOAD_IMAGE_GRAYSCALE);
Mat img2 = imread("box_in_scene.png", CV_LOAD_IMAGE_GRAYSCALE);
if (img1.empty() || img2.empty())
{
printf("Images non lisibles \n");
return -1;
}
// detecting keypoints
int hessian = 800;
Ptr<SURF> surf = SURF::create(hessian);
vector<KeyPoint> keypoints1, keypoints2;
surf->detect(img1, keypoints1);
surf->detect(img2, keypoints2);
waitKey(0);
return 0;
}
I'm trying to create Bag-Of-Words so I can train the SVM later. I'm new with OpenCV so I used a code that I found on the Internet. The problem is that I have the following error:
OpenCV Error: Assertion failed (!_descriptors.empty()) in add, file /build/buildd/opencv-2.4.8+dfsg1/modules/features2d/src/bagofwords.cpp, line 57
terminate called after throwing an instance of 'cv::Exception'
what(): /build/buildd/opencv-2.4.8+dfsg1/modules/features2d/src/bagofwords.cpp:57: error: (-215) !_descriptors.empty() in function add
Aborted (core dumped)
And here is the code:
#include <stdio.h>
#include <stdlib.h>
#include <opencv2/opencv.hpp>
#include <fstream>
#include <iostream>
#include <string>
#include <dirent.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
Ptr<FeatureDetector> features = FeatureDetector::create("FAST");
Ptr<DescriptorExtractor> descriptors = DescriptorExtractor::create("FAST");
Ptr<DescriptorMatcher> matcher = DescriptorMatcher::create("FlannBased");
//defining terms for bowkmeans trainer
TermCriteria tc(TermCriteria::MAX_ITER + TermCriteria::EPS, 10, 0.001);
int dictionarySize = 1000;
int retries = 1;
int flags = KMEANS_PP_CENTERS;
BOWKMeansTrainer bow_trainer(dictionarySize, tc, retries, flags);
BOWImgDescriptorExtractor bowDE(descriptors, matcher);
//training data now
Mat mat_features1, mat_features2;
Mat img = imread("../positive_images/2014-12-07 19-55-07 804ea51d (1).JPG", 0);
Mat img2 = imread("../positive_images/Pictures23.bmp_0000_0342_0104_0564_0543.png", 0);
vector<KeyPoint> keypoints, keypoints2;
features->detect(img, keypoints);
features->detect(img2,keypoints2);
descriptors->compute(img, keypoints, mat_features1);
descriptors->compute(img2, keypoints2, mat_features2);
bow_trainer.add(mat_features1);
bow_trainer.add(mat_features2);
Mat dictionary = bow_trainer.cluster();
bowDE.setVocabulary(dictionary);
return 0;
}
And here is how the code is compiled:
g++ BOW_creator.cpp -o BOW_creator `pkg-config --cflags --libs opencv`
Do you know what the problem could be? Can you tell me how to fix it?
Let me know if you need me to provide more information.
I'm trying using SURF feature detector but I'm always getting this error-
The program '[1120] Corner Detection.exe' has exited with code -1073741819 (0xc0000005) 'Access violation'.
Here is the code
#include "stdafx.h"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/nonfree/features2d.hpp"
#include <iostream>
#include <stdlib.h>
#include <vector>
#include <stdio.h>
#include "opencv2/core/core.hpp"
#include "opencv2\nonfree\nonfree.hpp"
using namespace cv;
using namespace std;
void foo(Mat &image1, Mat &image2)
{
int minHeassian = 400;
SurfFeatureDetector detector(minHeassian);
std::vector< KeyPoint > keypoints1, keypoints2;
keypoints1.resize(1000);
keypoints2.resize(1000);
detector.detect(image1, keypoints1); // <--- crashes at this line
detector.detect(image2, keypoints2); // <--- probably will crash here too
SurfDescriptorExtractor extractor;
Mat discriptors1, discriptors2;
extractor.compute(image1, keypoints1, discriptors1);
extractor.compute(image2, keypoints2, discriptors2);
FlannBasedMatcher matcher;
std::vector< DMatch > matches;
matcher.match(discriptors1, discriptors2, matches);
double minDist = 100;
for (int i = 0; i < matches.size(); ++i)
if (matches[i].distance < minDist)
minDist = matches[i].distance;
std::vector< DMatch > goodMatches;
for (int i = 0; i < matches.size(); ++i)
if (matches[i].distance <= max(0.02, (double)matches[i].distance))
goodMatches.push_back(matches[i]);
Mat matchImage;
drawMatches(image1, keypoints1, image2, keypoints2,
goodMatches, matchImage,
Scalar::all(-1), Scalar::all(-1), vector<char>(),
DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS);
namedWindow("Matches", WINDOW_AUTOSIZE);
imshow("Matches", matchImage);
waitKey(0);
}
int _tmain(int argc, _TCHAR* argv[])
{
cv::initModule_nonfree();
Mat left, right;
right = imread("D:\\right.jpg", IMREAD_COLOR);
left = imread("D:\\left.jpg", IMREAD_COLOR);
foo(left, right);
return 0;
}
I get the error at the line
detector.detect(image1, keypoints1);
I have following lib files mentioned to linker-
opencv_core249d.lib
opencv_imgproc249d.lib
opencv_highgui249d.lib
opencv_ml249d.lib
opencv_video249d.lib
opencv_features2d249d.lib
opencv_calib3d249d.lib
opencv_objdetect249d.lib
opencv_contrib249d.lib
opencv_legacy249d.lib
opencv_flann249d.lib
opencv_features2d249.lib
opencv_nonfree249.lib
I have tried everything I found on the Internet but nothing worked. What is wrong with this code?
I'm running VS 2013 on Windows 8.1 and I'm using OpenCV version 2.4.9.
Solved
It was a silly mistake. I used the library opencv_nonfree249.lib whereas I should be using opencv_nonfree249**d**.lib as I was working in debug mode.
You are using the library opencv_nonfree249.lib in a debug environment which is meant for release environment. Add a d to the lib name to make it opencv_nonfree249d.lib which will work for debug environment.
I am trying to track set of feature points in a sequence of grayscale images using OpenCV 2.4.0.
I already know how to implement SIFT or SURF for detecting feature points and initially computing the descriptors. However, I need help in computing the SIFT descriptor of a feature point whose location (u,v) is only known to me. A working example code for SIFT is shown below.
For example, if I use Haris corner detector to detect features at dv_scenePoints_t like:
cvGoodFeaturesToTrack (source2, eig_img, temp_img, dv_scenePoints_t, &corner_count, 0.3, 3.0, mask, 7, 1);
Then in such a case, how would I compute the SIFT descriptor of points at dv_scenePoints_t.
Also, if I have to track feature points by a particle filter. Then, how would I use the SIFT descriptor for computing the weight of each particle (feature point hypothesis).
Thanks.
#include "stdafx.h"
#include <stdio.h>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/nonfree/nonfree.hpp"
#include <opencv2/nonfree/features2d.hpp>
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/legacy/legacy.hpp"
#include "opencv2/legacy/compat.hpp"
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <string.h>
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char *argv[])
{
Mat source1 = imread("KITTI_train.png",CV_LOAD_IMAGE_GRAYSCALE);
Mat source2 = imread("KITTI_trainRotate90.png",CV_LOAD_IMAGE_GRAYSCALE);
vector<KeyPoint> dv_sceneKeypoints_t, dv_objectKeypoints_t;
vector< DMatch > matches;
SiftFeatureDetector detector(400,5,0.03);
detector.detect(source1, dv_objectKeypoints_t);
detector.detect(source2, dv_sceneKeypoints_t);
SiftDescriptorExtractor extractor;
Mat descriptors1,descriptors2;
extractor.compute(source1,dv_objectKeypoints_t,descriptors1);
extractor.compute(source2,dv_sceneKeypoints_t,descriptors2);
FlannBasedMatcher matcher;
matcher.match(descriptors1,descriptors2, matches);
Mat target;
drawMatches(source1,dv_objectKeypoints_t,source2,dv_sceneKeypoints_t,matches,target);
imshow("Matches", target);
waitKey(0);
return 0;
}
Keypoint structure contains some members such as size and response:
http://docs.opencv.org/modules/features2d/doc/common_interfaces_of_feature_detectors.html?#KeyPoint
You can use these features to determine the relative weights of particles.
I want to try the new class FREAK in OpenCV 2.4.2.
I tried to use common interface of feature detector to construct FREAK, but,of course, it doesn't work. How should I revise my code to get result?
#include <stdio.h>
#include <iostream>
#include <opencv\cxcore.h>
#include <opencv2\nonfree\features2d.hpp>
#include <opencv\highgui.h>
#include <opencv2\features2d\features2d.hpp>
#include <vector>
using namespace std;
using namespace cv;
int main(){
Mat mat1;
mat1 = imread("Testimg06.jpg",0);
vector<KeyPoint> P1;
Ptr<FeatureDetector> freakdes;
Ptr<DescriptorExtractor> descriptorExtractor;
freakdes = FeatureDetector::create("FREAK");
freakdes->detect(mat1,P1);
Mat keypoint_img;
drawKeypoints( mat1, P1, keypoint_img, Scalar::all(-1), DrawMatchesFlags::DEFAULT );
imshow("Keypoints 1", keypoint_img );
cvWaitKey(0);
}
FREAK is descriptor only. There is no corresponding feature detector.
So you need to combine it with one of the available detectors: FAST, ORB, SIFT, SURF, MSER or use goodFeaturesToTrack function.
There is an OpenCV example that shows how to use FREAK combined with FAST.
The basic instructions are:
FREAK extractor;
BruteForceMatcher<Hamming> matcher;
std::vector<KeyPoint> keypointsA, keypointsB;
Mat descriptorsA, descriptorsB;
std::vector<DMatch> matches;
FAST(imgA,keypointsA,10);
FAST(imgB,keypointsB,10);
extractor.compute( imgA, keypointsA, descriptorsA );
extractor.compute( imgB, keypointsB, descriptorsB );
matcher.match(descriptorsA, descriptorsB, matches);