Arbicon-net: Arbitrary continuous geometric transformation networks for image registration

This paper concerns the undetermined problem of estimating geometric transformation between image pairs. Recent methods introduce deep neural networks to predict the controlling parameters of hand-crafted geometric transformation models (e.g. thin-plate spline) for image registration and matching. However the low-dimension parametric models are incapable of estimating a highly complex geometric transform with limited flexibility to model the actual geometric deformation from image pairs. To address this issue, we present an end-to-end trainable deep neural networks, named Arbitrary Continuous Geometric Transformation Networks (Arbicon-Net), to directly predict the dense displacement field for pairwise image alignment. Arbicon-Net is generalized from training data to predict the desired arbitrary continuous geometric transformation in a data-driven manner for unseen new pair of images. Particularly, without imposing penalization terms, the predicted displacement vector function is proven to be spatially continuous and smooth. To verify the performance of Arbicon-Net, we conducted semantic alignment tests over both synthetic and real image dataset with various experimental settings. The results demonstrate that Arbicon-Net outperforms the previous image alignment techniques in identifying the image correspondences.