MGN-Net: Multigranularity Graph Fusion Network in Multimodal for Scene Text Spotting

In recent years, scene text spotting approaches have evolved into a multimodal-based framework. Although previous studies have highlighted the crucial importance of the intrinsic synergy between visual and linguistic features, recent advances in multimodal-based methods typically adopt an implicit fusion strategy with single granularity features, which cannot fully exploit the prior contextual relationships embedded in visual and semantic information. We argue that directly integrating visual and semantic features is suboptimal because the multigranularity structure of scene text images is quite different from that of natural images. To address this, we introduce a novel model called the multigranularity visual semantic interactive fusion network (MGN-Net), which comprises a visual semantic multigranularity feature extraction network (VSMN) and a multigranularity graph fusion learning network (MGFN). The VSMN adaptively extracts multigranularity visual and semantic features from the text image, thereby enriching the textual contextual relations. In the MGFN, a cross-modal and cross-hierarchy graph is constructed to align features from different modalities for deep intra- and inter-fusion. This approach also alleviates the inflexibility of the sequential structure when dealing with images of irregularly curved objects. Furthermore, the cross-hierarchy semantic features are designed to facilitate the training of MGN-Net. Experimental results demonstrate that our model significantly outperforms previous state-of-the-art models. The code will be released in MGN-Net.