A Complete Solution to Generalized Relative Pose Estimation From Affine Correspondences

In recent years, affine correspondences (ACs) have emerged as widely adopted alternative to point correspondences (PCs) in geometric problems in computer vision. An AC is composed of a PC across two different views plus an affine transformation between the small patches around this PC. Prior studies have shown that a single affine correspondence (AC) generally yields three independent constraints for estimating relative pose. This work addresses relative pose estimation in multi-perspective camera systems, a relevant problem given their prevalence in modern technologies such as autonomous vehicles and augmented reality. More specifically, we introduce the first comprehensive suite of minimal solvers for 6DoF relative pose estimation across multiple cameras using only two ACs, which is notably valuable for robust model fitting scenarios. We analyze all possible configurations of two ACs in two views, and present minimal solvers covering all identified minimal cases. We make use of the hidden variable technique to eliminate the translation parameters, and represent rotation using either Cayley parameters or quaternions. We furthermore introduce novel constraints on the generalized relative pose problem that are beneficial in deriving more compact solvers with fewer solutions. Comprehensive experiments on synthetic and real-world data show that the proposed affine correspondence-based solvers are highly effective and computationally efficient.