silentvalley's profile - activity

Thanks for the answer. I have updated my question. And to answer your other question - yes, i have used findHomography() to find the 2d image points to give as input to solvepnp().

i updated the link i referred to in the question

I have the 3D coordinates of 4 coplanar points of my target in the object coordinate system.I also have their the 2D coordinates in every frame of a video.I have also calculated the intrinsic parameters (M) for the camera, the R (rotation) and t (translation) matrices between the object coordinate system and the camera coordinate system using solvepnp(). I have read from here the complete process,which is very clear.It is also similar to the process I followed.Therefore I wanted to use the same equation

s [u v 1]^T = M ( R [X Y Z]^T + t)

for calculating my 3D coordinates but I have no constant as the link explains for calculating s.My target rotates about the x axis in the OpenCV coordinate system.My questions are -

1. Can anyone suggest me a way to find s? Is it definitely mandatory for this calculation or can i use s=1?
2. Is there any other methods for calculating the 3d point with what parameters I have?

I have been trying out Feature descriptors like ORB and SURF with OS X and recently switched to iOS platform. I wanted to try out the separate GPU version of these descriptors but only gpu version of SURF seems to be supported.Anyone have an idea if they might integrate the gpu module of OpenCV c++ for the iOS platform? Is there atleast a hint that there might be an update soon?