The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Software » comp.soft-sys.matlab

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: 3D Rotation Matrix not coming out to be Orthonormal
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  

Posts: 1
Registered: 11/19/13
3D Rotation Matrix not coming out to be Orthonormal
Posted: Nov 19, 2013 1:35 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

I am trying to implement 3D Augmented Reality using 4 marker points(plane).
So far I am only dealing with two image frames.One I consider my base view which is a rectangle in the centre of the image plane.Another is a plane which is rotated translated and scaled in real world.

I am using the following approach for solving this problem.
In order to place the 3D object on the plane,we need the 3D orientation of the plane in a frame.

The 3D orientation comprises of Rotation(along the three axis),translation (along x and y axis) and scaling(along z axis or translation along z axis tz).

The Rotation(in 3D world) of the plane is simply the inverse of the rotation(R) of the camera from the relation


So if we compute the Homography H between the two frames,we are good to go.

Now the translations tx and ty (in real 3D world) can be computed by simply applying rotation (Rinverse) on the 3D object,applying K on it (taking its image) and moving it according to the distance between the two images(take any one corner as reference e.g the top most left corner or even the center).

The problem that I am facing is that my R doesnt come out to be orthonormal and its not a minute difference.the determinant is almost close to zero.I have verified my H and it is correct.

can someone please help me?

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.