characteristics of what works well but then you take that and you are jointly optimizing for a 3d locations of those landmarks that agree with the observations you've made in the images while also solving for your own pose and to the the residual and this kind of objective will be the reprojection of that 3d point into your camera model for your pose and those are all variables in your optimization result in a pixel coordinate and then you would compare that pixel coordinate to the pixel coordinate at which you actually