Opencv Surf Bug error - opencv

Question

Anyone familiar with this error? I tested a surf descriptor in real-time and it worked well but after few seconds it crashes and I got this error.
It was related when no points were detected. I run my code again and have the detected object stays for more than 2 mins and still no error. but when I removed the object and there were no points, it crashes again after 40 secs.
#include <stdio.h>
#include <iostream>
#include <fstream>
#include <string>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/nonfree/features2d.hpp"
#include "opencv2/legacy/legacy.hpp"
using namespace cv;
using namespace std;
char key = 'a';
int framecount = 0;
SurfFeatureDetector detector(1000);
SurfDescriptorExtractor extractor;
FlannBasedMatcher matcher;
Mat frame, des_object, image;
Mat des_image, img_matches, H;
std::vector<KeyPoint> kp_object;
std::vector<Point2f> obj_corners(4);
std::vector<KeyPoint> kp_image;
std::vector<vector<DMatch > > matches;
std::vector<DMatch > good_matches;
std::vector<Point2f> obj;
std::vector<Point2f> scene;
std::vector<Point2f> scene_corners(4);
int main()
{
//reference image
Mat object = imread("D:/milo.jpg", CV_LOAD_IMAGE_GRAYSCALE );
if( !object.data )
{
std::cout<< "Error reading object " << std::endl;
return -1;
}
//compute detectors and descriptors of reference image
detector.detect( object, kp_object );
extractor.compute( object, kp_object, des_object );
//create video capture object
CvCapture* capture = cvCaptureFromCAM(0);
cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_WIDTH, 270);
cvSetCaptureProperty(capture, CV_CAP_PROP_FRAME_HEIGHT, 190);
//Get the corners from the object
obj_corners[0] = cvPoint(0,0);
obj_corners[1] = cvPoint( object.cols, 0 );
obj_corners[2] = cvPoint( object.cols, object.rows );
obj_corners[3] = cvPoint( 0, object.rows );
//wile loop for real time detection
while (key != 27)
{
Mat frame;
frame = cvQueryFrame(capture);
if (framecount < 5)
{
framecount++;
continue;
}
Mat des_image, img_matches;
std::vector<KeyPoint> kp_image;
std::vector<vector<DMatch > > matches;
std::vector<DMatch > good_matches;
std::vector<Point2f> obj;
std::vector<Point2f> scene;
std::vector<Point2f> scene_corners(4);
Mat H;
Mat image;
cvtColor(frame, image, CV_RGB2GRAY);
detector.detect( image, kp_image );
extractor.compute( image, kp_image, des_image );
matcher.knnMatch(des_object, des_image, matches, 2);
int goodMatchesCounter =0;
for(int i = 0; i < min(des_image.rows-1,(int) matches.size()); i++) //THIS LOOP IS
SENSITIVE TO SEGFAULTS
{
if(((int)matches[i].size()<=2 && (int)matches[i].size()>0) && (matches[i}
[0].distance<0.6*(matches[i][1].distance)))
{
// good_matches.push_back(matches[i][0]);
obj.push_back( kp_object[ matches[i][0].queryIdx ].pt );
scene.push_back( kp_image[ matches[i][0].trainIdx ].pt );
goodMatchesCounter++;
}
}
//Draw only "good" matches
// drawMatches( object, kp_object, image, kp_image, good_matches, img_matches,
Scalar::all(-1), Scalar::all(-1), vector<char>(),
DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
if (goodMatchesCounter >= 4)
{
H = findHomography( obj, scene, CV_RANSAC );
perspectiveTransform( obj_corners, scene_corners, H);
//Draw lines between the corners (the mapped object in the scene image )
line( image, scene_corners[0], scene_corners[1], Scalar( 0, 0, 0), 4 );
line( image, scene_corners[1], scene_corners[2], Scalar( 0, 0, 0),
4 );
line( image, scene_corners[2], scene_corners[3], Scalar( 0, 0, 0),
4 );
line( image, scene_corners[3], scene_corners[0], Scalar( 0, 0, 0),
4 );
}
//Show detected matches
imshow( "Good Matches", image );
key = waitKey(1);
}
return 0;
}