bymulker's profile - activity

Thanks but the datasets before 2014 dont have any sufficient calib. data. I downloaded the bicycle from here : http://vision.middlebury.edu/stereo/d... which has calib data and wrote a little utility to read in c++. The cameras are co-planar for all samples in the directory so it should be straightforward to build Q matrix. I already reprojected but the result is somewhat noisy and the bicycle seems to be hole! (out of disparity range)

You can get good results for the aloe vera plant that is found in the OpenCV examples data directory with sbm and sgbm respectively ;

      cvtColor( viewL, viewL, COLOR_RGB2GRAY );
  cvtColor( viewR, viewR, COLOR_RGB2GRAY );
  sStereo->alg = StereoCameraRig::STEREO_BM;
  sStereo->SADWindowSize = 9;
  sStereo->numberOfDisparities = 112;
  sStereo->preFilterSize = 5;
  sStereo->preFilterCap = 61;
  sStereo->minDisparity = -39;
  sStereo->textureThreshold = 507;
  sStereo->uniquenessRatio = 0;
  sStereo->speckleWindowSize = 0;
  sStereo->speckleRange = 8;
  sStereo->disp12MaxDiff = 1;

or : ..

   sStereo->alg = StereoCameraRig::STEREO_SGBM;
  sStereo->SADWindowSize = 11;
  sStereo->numberOfDisparities = 192;
  sStereo->preFilterCap = 4;
  sStereo->minDisparity = -64;
  sStereo->uniquenessRatio = 1;
  sStereo->speckleWindowSize = 150;
  sStereo->speckleRange = 1;
  sStereo->disp12MaxDiff = 1;
  sStereo->P1 = 600;
  sStereo->P2 = 2400;
  sStereo->textureThreshold = 500;

You have to convert images to grey for sbm while sgbm can work with color images without any problems.

Note: The left and right images of the plant are rectified meaning y-axis aligned. In order to make such a rectification (from scratch) you must stereo calibrate the system to get intrinsic and extrinsic parameters of the system.

Hi,

I dont know if it is late but i can send the settings for sgbm :

sStereo->alg = StereoCameraRig::STEREO_SGBM;
  sStereo->SADWindowSize = 3;
  sStereo->numberOfDisparities = 192;
  sStereo->preFilterCap = 4;
  sStereo->minDisparity = -64;
  sStereo->uniquenessRatio = 1;
  sStereo->speckleWindowSize = 150;
  sStereo->speckleRange = 1;
  sStereo->disp12MaxDiff = 1;
  sStereo->fullDP = false;
  sStereo->P1 = 600;
  sStereo->P2 = 2400;
  sStereo->textureThreshold = 500;

  stRig.CreateUpdateStereoMatcher();

  stRig.getDisparityMap(viewL, viewR, dispMap, false);

  normalize(dispMap, disp8, 0, 255, CV_MINMAX, CV_8U);

  showImage(disp8, true);

In any case i got my tiny shiny disparity map :) but cannot reproject3d as i cannot see any extrinsics files shipped with OpenCV!! (the instrinscs file is 'intrinsics.yml' file if i'm not wrong) Can someone point out where or a better sample maybe?

Hi community,

I was just tracking the samples shipped with OpenCV created the disparity map for the aloe plant but cannot reproject3d as i cannot find the extrinsics file in the samples directory. I know this is a loser question :) maybe someone can point out a better example data set?

The example file is ; /opencv\sources\samples\cpp\stereo_match.cpp

..but this is a console program and expects the file names as the parameters which i do not know where to get. I'm assuming the right intrinsics file is the 'intrinsics.yml' file found in /opencv\sources\samples\data, but it is impossible without having the extrinsics to reproject3d. The disparity map settings is as follows for those who might be interested:

sStereo->alg = StereoCameraRig::STEREO_SGBM;
  sStereo->SADWindowSize = 11;
  sStereo->numberOfDisparities = 192;
  sStereo->preFilterCap = 4;
  sStereo->minDisparity = -64;
  sStereo->uniquenessRatio = 1;
  sStereo->speckleWindowSize = 150;
  sStereo->speckleRange = 1;
  sStereo->disp12MaxDiff = 1;
  sStereo->P1 = 600;
  sStereo->P2 = 2400;
  sStereo->textureThreshold = 500;

  stRig.CreateUpdateStereoMatcher();

  stRig.getDisparityMap(viewL, viewR, dispMap, false);

  normalize(dispMap, disp8, 0, 255, CV_MINMAX, CV_8U);

  showImage(disp8, true);

Thank you very much!

(This is my first post (hope will not be the last!) and it is my pleasure to be here in such a great library's forum with you.)