How to get the findHomography result's position relative to scene?

asked 2013-07-31 07:53:04 -0600

Ted WONG
21 ●1 ●5

I follow the following tutorial:

http://docs.opencv.org/doc/tutorials/features2d/feature_homography/feature_homography.html#feature-homography

And I can detect the object I want. But I would like to know the position, and the coordinate is relative in the scene image. And I take the source code's scene_corners vendor, but the position is totally wrong. How can I transfer it the the right position? Thanks.

edit retag flag offensive close merge delete

add a comment

1 answer

Sort by » oldest newest most voted

answered 2013-07-31 10:17:50 -0600

Mostafa Sataki

2529 ●12 ●18 ●48 http://www.7khatcode.com/

updated 2013-07-31 10:19:44 -0600

For solve this problem in the first use findHomography() then compute rotation value in the last use perspectiveTransform() to transform object points to scene points.

 const int n = 100;
 Point2f object_points[n],scene_points[n];
  Mat H = findHomography(object_points, scene_points, CV_RANSAC );
  float roatation =  acos( H.at<double>(0,0)) * 180/CV_PI;
  perspectiveTransform( object_points, scene_points, H);