A motion determination system is disclosed. The system may calculate one or more visual-odometry outputs. The system may determine a plurality of figure of merits, wherein each of the plurality of figure of merits is associated with one of a plurality of parameters affecting the calculation of the one or more visual-odometry outputs, and each of the plurality of figure of merits is indicative of an accuracy of the visual-odometry outputs. The system may calculate a combined figure of merit based on the plurality of figure of merits. The system may calculate an error estimate for the one or more visual-odometry outputs based on the combined figure of merit.