What is "bundle adjustment"

n. (context comptheory computer graphics English) A process used in the reconstruction of a three-dimensional model from a set of photographs, simultaneously refine the coordinates describing the scene geometry as well as the parameters of the relative motion and the optical characteristics of the cameras that took the pictures.

Given a set of images depicting a number of 3D points from different viewpoints, bundle adjustment can be defined as the problem of simultaneously refining the 3D coordinates describing the scene geometry, the parameters of the relative motion, and the optical characteristics of the camera(s) employed to acquire the images, according to an optimality criterion involving the corresponding image projections of all points.