What's the definition of absolute pose

[colmap]

What's the definition of absolute pose

[mihaidusmanu]

Hello. We are using the colmap pose convention - i.e., world-to-camera with qvec in format w, x, y, z and tvec in format x, y, z (see https://colmap.github.io/format.html#images-txt). Thus, given a 3D point in world coordinates P, to obtain the coordinates in camera frame, you have to do something along the lines:

def mat_from_quat(quat):
    # quat is [w, x, y, z]
    from scipy.spatial.transform import Rotation as R
    rot = R.from_quat([quat[1], quat[2], quat[3], quat[0]]) # expects [x, y, z, w]
    mat = rot.as_matrix()
    return mat

R = mat_from_quat(qvec)
P_camera = R @ P + tvec

[alexs7]

@mihaidusmanu This should work also when the points are in camera coordinates ?
At the end of the end they are just 3D points (does it matter if they are in camera space or world ) ?