Ask Your Question
1

3d point reconstruction

asked 2014-05-17 06:58:36 -0600

GiulSDU gravatar image

Hi, i have two 2d points from two rectified images, they match. How can i now compute the 3d point? I have both projection matrix. thank you

edit retag flag offensive close merge delete

Comments

1
  • if you have a stereo-rig, and did stereocalibration, you can build disparity via blockmatching, and use reprojectimageto3d

  • if you don't have a Q-matrix, you will need more than 2 images, and use triangulation

berak gravatar imageberak ( 2014-05-17 07:32:30 -0600 )edit

1 answer

Sort by ยป oldest newest most voted
4

answered 2014-05-17 17:14:30 -0600

You could use cv::triangulatePoints:

http://docs.opencv.org/modules/calib3d/doc/camera_calibration_and_3d_reconstruction.html#triangulatepoints

It gives you homogeneous 3D points from two projection matrices and corresponding pixels.

edit flag offensive delete link more

Comments

that works fine thanks!! i tried to crop the original images a little bit and to use the same matching algorithm as before..the problem is that i get very different 3d-points coordinates...but the object is just the same....and i did not change the position..i just cropped the image..aren t i suppose to get the same 3d point regardless to the xy coordinate of the object in the image? can you see the error somewhere? thank you

GiulSDU gravatar imageGiulSDU ( 2014-05-18 08:37:35 -0600 )edit

Question Tools

Stats

Asked: 2014-05-17 06:58:36 -0600

Seen: 526 times

Last updated: May 17 '14