OpenCV Q&A Forum - RSS feedhttp://answers.opencv.org/questions/OpenCV answersenCopyright <a href="http://www.opencv.org">OpenCV foundation</a>, 2012-2018.Thu, 02 May 2013 06:44:45 -0500calculate 3d pose of sphere based on 2d ellipsehttp://answers.opencv.org/question/12789/calculate-3d-pose-of-sphere-based-on-2d-ellipse/Hello all,
at the moment I'm using OpenCV to detect balls in an image by finding the 2d ellipse of the balls.
I now need to find out the exact position of the ball in world coordinates - I know the radius of the balls. If the ball is lying close to the optical center of the camera then the position is quite accurate - but if the ball moves to the borders of the image, the position has a growing error, because of the perspective distortion of the camera - the ball is seen from the side for example.
I read several papers about this problem and there seems to be a solution (http://www.mie.utoronto.ca/labs/ciml/projects/rob_vision/Tony.pdf on page 4) but I'm not sure how to implement this.
My current idea:<br />
1. remove radial distortion from the image (I have the intrinsic parameters of the camera)<br />
2. detect the ellipse in the image<br />
3. use some magic maths as written in the paper to estimate the 3d pose
Has anyone some expirience with this?
I hope someone can point me in the right direction.
Thanks a lot!Thu, 02 May 2013 06:44:45 -0500http://answers.opencv.org/question/12789/calculate-3d-pose-of-sphere-based-on-2d-ellipse/