“…These methods formulate transformation synchronization as low-rank matrix recovery, where the input relative transformations are considered noisy measurements of this low-rank matrix. In the literature, people have proposed convex optimization [47,23,24,13], non-convex optimization [11,53,33,26], and spectral techniques [31,25,39,38,42,44,7,2,9] for solving various low-rank matrix recovery formulations. Com-pared with the first category of methods, the second category of methods is computationally more efficient.…”