Bridging Modality Gap for Visual Grounding with Effecitve Cross-modal Distillation

Visual grounding aims to align visual information of specific regions of images with corresponding natural language expressions. Current visual grounding methods leverage pre-trained visual and language backbones separately to obtain visual features and linguistic features. Although these two types of features are then fused via delicately designed networks, the heterogeneity of the features makes them inapplicable for multi-modal reasoning. This problem arises from the domain gap between the single-modal pre-training backbone used in current visual grounding methods, which can hardly be overcome by the traditional end-to-end training method. To alleviate this, our work proposes an Empowering pre-trained model for Visual Grounding (EpmVG) framework, which distills a multimodal pre-trained model to guide the visual grounding task. EpmVG is based on a novel cross-modal distillation mechanism, which can effectively introduce the consistency information of images and texts in the pre-trained model, to reduce the domain gap existing in the backbone networks, thereby improving the performance of the model in the visual grounding task. Extensive experiments are carried out on five conventionally used datasets, and results demonstrate that our method achieves better performance than state-of-the-art methods.

Open Compound Domain Adaptation with Object Style Compensation for Semantic Segmentation

Many methods of semantic image segmentation have borrowed the success of open compound domain adaptation. They minimize the style gap between the images of source and target domains, more easily predicting the accurate pseudo annotations for target domain's images that train segmentation network. The existing methods globally adapt the scene style of the images, whereas the object styles of different categories or instances are adapted improperly. This paper proposes the Object Style Compensation, where we construct the Object-Level Discrepancy Memory with multiple sets of discrepancy features. The discrepancy features in a set capture the style changes of the same category's object instances adapted from target to source domains. We learn the discrepancy features from the images of source and target domains, storing the discrepancy features in memory. With this memory, we select appropriate discrepancy features for compensating the style information of the object instances of various categories, adapting the object styles to a unified style of source domain. Our method enables a more accurate computation of the pseudo annotations for target domain's images, thus yielding state-of-the-art results on different datasets.