  Guided depth super-resolution (GDSR) involves restoring missing depth details
using the high-resolution RGB image of the same scene. Previous approaches have
struggled with the heterogeneity and complementarity of the multi-modal inputs,
and neglected the issues of modal misalignment, geometrical misalignment, and
feature selection. In this study, we rethink some essential components in GDSR
networks and propose a simple yet effective Dynamic Dual Alignment and
Aggregation network (D2A2). D2A2 mainly consists of 1) a dynamic dual alignment
module that adapts to alleviate the modal misalignment via a learnable domain
alignment block and geometrically align cross-modal features by learning the
offset; and 2) a mask-to-pixel feature aggregate module that uses the gated
mechanism and pixel attention to filter out irrelevant texture noise from RGB
features and combine the useful features with depth features. By combining the
strengths of RGB and depth features while minimizing disturbance introduced by
the RGB image, our method with simple reuse and redesign of basic components
achieves state-of-the-art performance on multiple benchmark datasets. The code
is available at https://github.com/JiangXinni/D2A2.
