Existing Transformer-based RGBT tracking methods either use cross-attention
to fuse the two modalities, or use self-attention and cross-attention to model
both modality-specific and modality-sharing information. However, the
significant appearance gap between modalities limits the feature representation
ability of certain modalities during the fusion process. To address this
problem, we propose a novel Progressive Fusion Transformer called ProFormer,
which progressively integrates single-modality information into the multimodal
representation for robust RGBT tracking. In particular, ProFormer first uses a
self-attention module to collaboratively extract the multimodal representation,
and then uses two cross-attention modules to interact it with the features of
the dual modalities respectively. In this way, the modality-specific
information can well be activated in the multimodal representation. Finally, a
feed-forward network is used to fuse two interacted multimodal representations
for the further enhancement of the final multimodal representation. In
addition, existing learning methods of RGBT trackers either fuse multimodal
features into one for final classification, or exploit the relationship between
unimodal branches and fused branch through a competitive learning strategy.
However, they either ignore the learning of single-modality branches or result
in one branch failing to be well optimized. To solve these problems, we propose
a dynamically guided learning algorithm that adaptively uses well-performing
branches to guide the learning of other branches, for enhancing the
representation ability of each branch. Extensive experiments demonstrate that
our proposed ProFormer sets a new state-of-the-art performance on RGBT210,
RGBT234, LasHeR, and VTUAV datasets.Comment: 13 pages, 9 figure