Structure from motion with covariance in ROS

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I am trying to use some objects in the ceiling as markers, using a camera faced up mounted on a mobile base. Is there any library that could take multiple PoseWithCovariance (camera's poses in odom frame) input combined with the 2D pixel observation of the marker at those positions and the noise matrix R (variances for x and y pixel observations) of the camera and give as output a 3D PoseWithCovariance of that marker? Until now I implemented the structure from motion by myself but I don't really know where to start to integrate the covariances of the different poses I used and the camera noise into the algorithm.