How to use mask in drawMatches function c++ - c++

Question

I´m doing a program with opencv and a stereo camera. I want to know what detected point in firs camera below with what detected point in second camera. The think is I have some detectors, extractors and matches methods, and following the example in opencv I have a algorithm to filter the matches and only draw good matches but in my case the min_dist parameter depends on my trackBar position.
This is the code of the opencv example:http://docs.opencv.org/doc/tutorials/features2d/feature_flann_matcher/feature_flann_matcher.html#feature-flann-matcher
And there are the changes that I did to move the minimum distance between matches.
//TrackBar position
dist_track = getTrackbarPos(nombreTrackbar, BUTTON_WINDOW);
cout <<"Posicion de la barra: " << dist_track << endl;
good_matches.clear();
//Obtain good_matches
for( int i = 0; i < descriptors[0].rows; i++ )
{ if( matches[i].distance <= coef*dist_track)
{ good_matches.push_back( matches[i]);}
}
The main think is that when I put the trackBar at the begining I have correct matches but when the trackbar is put in the end, the matches that I found aren´t correct. In this case I found a lot of matches but many of them are wrong.
Now I´m trying to do correctly the images. I want to use a mask in drawmatches function to force that the second-camera-points detected has to be near to the epipolar line. Can someone ask me something about it?
Do someone knows how to use the mask parameter to force that the founded matcher need to be in the epipolar line?
Or how to create the mask parameter?
Thanks friends!

Answer 1

Finally I decided to change the way i will operate. I'm trying to cut the originals images and keep only the necessary information. I mean I get out the information of the photo that it doesn't mind for my application and only keep the information that I'm goint to use.
My idea is to use the epipolar lines of both cameras to determine the interest area that I have, I will calculate where is the epipolar lines in both images and then y cut the images and only keep the information where the epipolar lines are.
Doing it I obtain two new images and my idea is to pass the news images to the matcher method to see if I can obtain more successful matching.
Image before cut off:
Image later cut off:
However I have a problem with the computation time. My code requiresa high computacional cost and sometimes the program fails. The error says "Segmentation fault:11".
"Bus error 10" appears if I quit the waitKey() line.
My code to copy the main image content in the second one is there:
> for (int i=0; i<RightEpipolarLines.rows; i++) {
> float m = -RightEpipolarLines(i, 0)/RightEpipolarLines(i, 1);
> float n = -RightEpipolarLines(i, 2)/RightEpipolarLines(i, 1);
> for (int x = 0; x < 480; x++) {
> float y_prima = m*x + n;
> int y = int (y_prima);
> (cut_image[0].at<float>(y, x)) = capture[0].at<float>(y, x);
> }
>
> }
> waitKey();
> for (int i = 0; i<LeftEpipolarLines.rows; i++) {
> float m = LeftEpipolarLines(i, 0)/LeftEpipolarLines(i, 1);
> float n = -LeftEpipolarLines(i, 2)/LeftEpipolarLines(i, 1);
> for (int x = 0; x < 480; x++) {
> float y_prima = m*x + n;
> int y = int (y_prima);
> (cut_image[1].at<float>(y, x)) = capture[1].at<float>(y, x);
> }
> }
> waitKey();
Does someone know how to pass the information between real capture and cut_image more efficiently? I only would like to pass the pixels information that are near the epipolar lines.