Rethinking Encoder-Decoder Flow Through Shared Structures
Frederik Laboyrie, Mehmet Kerim Yucel, Albert Saa-Garriga
TL;DR
The paper addresses the stagnation of decoder architectures in dense prediction by introducing banks—globally shared tensors that augment each decoding block with cross-block context. Specifically, feature banks $B_f$ and sampling banks $B_s$ are generated by a bank generator $Z$ from the encoder and interact with decoding features via reweighting $X' = X \times \mathrm{conv}(\mathrm{concat}(B, X))$ and guided dynamic upsampling guided by $B_s$ using DySample, with downsampling to decoding resolutions. Empirically, banks yield consistent accuracy gains across ViT-S/B and RepViT on NYUv2 and synthetic datasets, with modest increases in parameters and GFLOPs, and clear qualitative improvements such as reduced artifacts and sharper edges. The approach is presented as a generic add-on to ViT-based dense predictors, with potential applicability to other dense-prediction tasks beyond depth estimation. $B_f$ and $B_s$ provide a unified mechanism to couple encoder features and decoding steps, enabling richer context propagation throughout the decoder pipeline.
Abstract
Dense prediction tasks have enjoyed a growing complexity of encoder architectures, decoders, however, have remained largely the same. They rely on individual blocks decoding intermediate feature maps sequentially. We introduce banks, shared structures that are used by each decoding block to provide additional context in the decoding process. These structures, through applying them via resampling and feature fusion, improve performance on depth estimation for state-of-the-art transformer-based architectures on natural and synthetic images whilst training on large-scale datasets.
