how inverse an cv::Affine3d transformation

Question

I use opencv 3.0.

I use a cv::Affine3d declared like this:

cv::Vec3d om = ...;
cv::Vec3d T = ...;
cv::Affine3d aff(om, T);

Then I use aff to transform X into Y like this:

cv::Vec3d X;
cv::Vec3d Y = aff*X;

Now, I would like do the inverse transformation to transform Y into X?

Answer 1

I would assume that

cv::Affine3d affInverse = aff.inv(); // Calls inv() on the internal matrix
                                     // and returns a new object from that.

cv::Vec3d xPrime = affInverse * Y;

does the trick. See the header you mentioned for more information.

Also, the documentation should provide some more information about the Matx stored in Affine3d.

Hope that helps!