A Learning-Based Optimization Algorithm: Image Registration Optimizer Network

Remote sensing image registration is valuable for image-based navigation system despite posing many challenges. As the search space of image registration is usually nonconvex, the optimization algorithm, which aims to find the optimal parameters in search space, is a challenging step. Conventional optimization algorithms can hardly reconcile the contradiction of rapid convergence and global optimization. In this letter, a novel learning-based optimization algorithm named image registration optimizer network (IRON) is proposed, which can predict the global optimum straightforwardly. The IRON is trained by a 3-D tensor (
$9\times 9\,\,\times9$
) which consists of similar metric values. Each value of the 3-D tensor corresponds to the initial parameters’
$9 \times 9 \times 9$
neighbors in the search space. The 3-D tensor’s label is a vector which points to the global optimal parameters from the initial parameters. Because of the special design, our IRON could predict the global optimum directly. The experimental results demonstrate that the proposed algorithm performs better than other classical optimization algorithms as it shows higher accuracy, lower root-of-mean-square error (RMSE), and more convergence efficiency. The code is publicly available at
https://www.github.com/jaxwangkd04/IRON
.