I have some difficulties in understanding how the efficient_pnp() function works and what it accepts as arguments.
My setting is the following:
I have 2d points in the image space, i.e. pixel coordinates, and corresponding 3d coordinates in the object coordinate frame. I want to find the camera orientation relative to that object using PnP.
In order to do this, I first convert the 2d pixel coordinates to the camera rays using a camera intrinsics matrix K:
x2d_cam = K^-1 @ x2d
Then, I do the perspective projection and take the first two components of the resulting points:
x2d_cam = x2d_cam[..., :2] / x2d_cam[..., 2],
to obtain "uncalibrated 2D points".
According to the documentation of the function, this is what this function is expected to have as inputs.
the efficient_pnp() function is then called with the following args: efficient_pnp(x3d, x2d_cam)
First observation, it doesn't work at all as cv.solvePnP function, the results are quite different. And the other thing is that I always got warnings that some points are behind the camera. i.e. have z < 0.
What am I doing wrong and need to change in my approach?
Hello.
I have some difficulties in understanding how the efficient_pnp() function works and what it accepts as arguments. My setting is the following: I have 2d points in the image space, i.e. pixel coordinates, and corresponding 3d coordinates in the object coordinate frame. I want to find the camera orientation relative to that object using PnP.
In order to do this, I first convert the 2d pixel coordinates to the camera rays using a camera intrinsics matrix K:
x2d_cam = K^-1 @ x2dThen, I do the perspective projection and take the first two components of the resulting points:
x2d_cam = x2d_cam[..., :2] / x2d_cam[..., 2], to obtain "uncalibrated 2D points".According to the documentation of the function, this is what this function is expected to have as inputs.
the
efficient_pnp()function is then called with the following args:efficient_pnp(x3d, x2d_cam)First observation, it doesn't work at all as cv.solvePnP function, the results are quite different. And the other thing is that I always got warnings that some points are behind the camera. i.e. have z < 0.
What am I doing wrong and need to change in my approach?
Thanks.