Vision-language models (VLMs) have gained widespread attention for their strong zero-shot capabilities across numerous downstream tasks. However, these models assume that each test image’s class label is drawn from a predefined label set and lack a reliable mechanism to reject samples from emerging unknown classes when only unlabeled data are available. To address this gap, open-set domain adaptation methods retrain models to push potential unknowns away from known clusters. Yet, some unknown samples remain stably anchored to specific known classes in the VLM feature space due to semantic relevance, which is termed as Semantic Affinity Anchoring (SAA). Forcibly repelling these samples unavoidably distorts the native geometry of VLMs and degrades performance. Meanwhile, existing score‑based unknown detectors use simplistic thresholds and suffer from threshold sensitivity, resulting in sub‑optimal performance. To address aforementioned issues, we propose VLM-OpenXpert, which comprises two training‑free, plug‑and‑play inference modules. SUFF performs SVD on high-confidence unknowns to extract a low-rank "unknown subspace". Each sample’s projection onto this subspace is weighted and softly removed from its feature, suppressing unknown components while preserving semantics. BGAT corrects score skewness via a Box–Cox transform, then fits a bimodal Gaussian mixture to adaptively estimate the optimal threshold balancing known-class recognition and unknown-class rejection. Experiments on 9 benchmarks and three backbones (CLIP, SigLIP, ALIGN) under Source-Free OSDA settings show that our training-free pipeline matches or outperforms retraining-heavy state-of-the-art methods, establishing a powerful lightweight inference calibration paradigm for open-set VLM deployment.

Multimodal Misinformation Detection (MMD) refers to the task of detecting social media posts involving misinformation, where the post often contains text and image modalities. However, by observing the MMD posts, we hold that the text modality may be much more informative than the image modality because the text generally describes the whole event/story of the current post but the image often presents partial scenes only. Our preliminary empirical results indicate that the image modality exactly contributes less to MMD. Upon this idea, we propose a new MMD method named RETSIMD. Specifically, we suppose that each text can be divided into several segments, and each text segment describes a partial scene that can be presented by an image. Accordingly, we split the text into a sequence of segments, and feed these segments into a pre-trained text-to-image generator to augment a sequence of images. We further incorporate two auxiliary objectives concerning text-image and image-label mutual information, and further post-train the generator over an auxiliary text-to-image generation benchmark dataset. Additionally, we propose a graph structure by defining three heuristic relationships between images, and use a graph neural network to generate the fused features. Extensive empirical results validate the effectiveness of RETSIMD.

The development of Internet technology has led to an increased prevalence of misinformation, causing severe negative effects across diverse domains. To mitigate this challenge, Misinformation Detection (MD), aiming to detect online misinformation automatically, emerges as a rapidly growing research topic in the community. In this paper, we propose a novel plug-and-play augmentation method for the MD task, namely Misinformation Detection with Potential Commonsense Conflict (MD-PCC). We take inspiration from the prior studies indicating that fake articles are more likely to involve commonsense conflict. Accordingly, we construct commonsense expressions for articles, serving to express potential commonsense conflicts inferred by the difference between extracted commonsense triplet and golden ones inferred by the well-established commonsense reasoning tool COMET. These expressions are then specified for each article as augmentation. Any specific MD methods can be then trained on those commonsense-augmented articles. Besides, we also collect a novel commonsense-oriented dataset named CoMis, whose all fake articles are caused by commonsense conflict. We integrate MD-PCC with various existing MD backbones and compare them across both 4 public benchmark datasets and CoMis. Empirical results demonstrate that MD-PCC can consistently outperform the existing MD baselines.

Over the past decade, social media platforms have been key in spreading rumors, leading to significant negative impacts. To counter this, the community has developed various Rumor Detection (RD) algorithms to automatically identify them using user comments as evidence. However, these RD methods often fail in the early stages of rumor propagation when only limited user comments are available, leading the community to focus on a more challenging topic named Rumor Early Detection (RED). Typically, existing RED methods learn from limited semantics in early comments. However, our preliminary experiment reveals that the RED models always perform best when the number of training and test comments is consistent and extensive. This inspires us to address the RED issue by generating more human-like comments to support this hypothesis. To implement this idea, we tune a comment generator by simulating expert collaboration and controversy and propose a new RED framework named CAMERED. Specifically, we integrate a mixture-of-expert structure into a generative language model and present a novel routing network for expert collaboration. Additionally, we synthesize a knowledgeable dataset and design an adversarial learning strategy to align the style of generated comments with real-world comments. We further integrate generated and original comments with a mutual controversy fusion module. Experimental results show that CAMERED outperforms state-of-the-art RED baseline models and generation methods, demonstrating its effectiveness.

Cross-scene classification of remote sensing (RS) imagery faces significant challenges due to large domain discrepancies and diverse imaging conditions, which hinder the acquisition of generalizable multi-modal semantic features. Unsupervised domain adaptation (UDA) has emerged as a promising solution for knowledge transfer across domains. Although prompt learning and vision-language models (VLMs) have recently been employed to enrich cross-modal information and improve the effectiveness of UDA, most existing methods either design prompts solely for the textual modality or employ unidirectional mapping from textual to visual prompts, resulting in insufficient cross-modal fusion. To overcome these limitations, we propose Mutual Cascade Prompting for Probability-Aligned Unsupervised Domain Adaptation in cross-scene classification (MCPPA). Within this framework, the progressive attention interactive prompt (PAIP) module implements a cascade prompt mechanism where, at each layer, visual and textual prompts from the previous stage are mutually updated through a cross-attention module. This mutual learning allows both branches to progressively integrate and reinforce multi-modal information in a deep and hierarchical fashion. Additionally, the category probability discrepancy measure (CPDM) module aligns the probability matrices of source and target domains using the nuclear norm within an adversarial training paradigm, while the feature stability constraint (FSC) module enforces consistency between learnable prompt features and those from the pre-trained model, enhancing overall robustness. Extensive evaluations on 30 transfer tasks across 10 benchmark RS datasets confirm that MCPPA consistently outperforms existing advanced methods, highlighting its effectiveness and broad application potential.

With the rapid advancement of remote sensing (RS) technologies, the role of automated cross-scene recognition in environmental monitoring and resource management has become increasingly prominent. Facing the challenge of scarce annotated data in RS, unsupervised domain adaptation (UDA) technology stands out for its ability to transfer knowledge across domains. Most RS scene recognition methods based on prompt learning only optimize the textual component. They cannot flexibly and dynamically adjust textual and visual representations, which may lead to poor performance when facing complex UDA tasks. In order to solve this problem, we propose the prompt-integrated adversarial UDA for scene recognition (PADA-Net) framework, introducing a prompt-integrated method in the domain adaptation task of RS scene classification for the first time to enhance the semantic association between images and text and better align visual-linguistic representations. PADA-Net fosters cross-modal information exchange via an interactive bridging mechanism (IBM) and combines dual Meta-nets to reinforce feature discriminability. The collaborative operation of these two components constitutes a novel system for feature discrimination. Additionally, we incorporate optimal transport theory to provide meaningful gradients and geometric guidance for training, and we use game-theoretic strategies to further enhance the efficient alignment of feature distributions, thereby addressing the domain shift problem. Finally, we carry out 24 different scene recognition tasks on multiple RS benchmark datasets, such as AID and WHU-RS19, and several experimental findings verify the excellence of our suggested approach.

Various social media platforms, e.g., Twitter and Reddit, allow people to disseminate a plethora of information more efficiently and conveniently. However, they are inevitably full of misinformation, causing damage to diverse aspects of our daily lives. To reduce the negative impact, timely identification of misinformation, namely Misinformation Detection (MD), has become an active research topic receiving widespread attention. As a complex phenomenon, the veracity of an article is influenced by various aspects. In this paper, we are inspired by the opposition of intents between misinformation and real information. Accordingly, we propose to reason the intent of articles and form the corresponding intent features to promote the veracity discrimination of article features. To achieve this, we build a hierarchy of a set of intents for both misinformation and real information by referring to the existing psychological theories, and we apply it to reason the intent of articles by progressively generating binary answers with an encoder-decoder structure. We form the corresponding intent features and integrate it with the token features to achieve more discriminative article features for MD. Upon these ideas, we suggest a novel MD method, namely Detecting Misinformation by Integrating Intent featuRes (DM-INTER). To evaluate the performance of DM-INTER, we conduct extensive experiments on benchmark MD datasets. The experimental results validate that DM-INTER can outperform the existing baseline MD methods.

Nowadays, misinformation is widely spreading over various social media platforms and causes extremely negative impacts on society. To combat this issue, automatically identifying misinformation, especially those containing multimodal content, has attracted growing attention from the academic and industrial communities, and induced an active research topic named Multimodal Misinformation Detection (MMD). Typically, existing MMD methods capture the semantic correlation and inconsistency between multiple modalities, but neglect some potential clues in multimodal content. Recent studies suggest that manipulated traces of the images in articles are non-trivial clues for detecting misinformation. Meanwhile, we find that the underlying intentions behind the manipulation, e.g., harmful and harmless, also matter in MMD. Accordingly, in this work, we propose to detect misinformation by learning manipulation features that indicate whether the image has been manipulated, as well as intention features regarding the harmful and harmless intentions of the manipulation. Unfortunately, the manipulation and intention labels that make these features discriminative are unknown. To overcome the problem, we propose two weakly supervised signals as alternatives by introducing additional datasets on image manipulation detection and formulating two classification tasks as positive and unlabeled learning problems. Based on these ideas, we propose a novel MMD method, namely Harmfully Manipulated Images Matter in MMD (Hami-m3d). Extensive experiments across three benchmark datasets can demonstrate that Hami-m3d can consistently improve the performance of any MMD baselines.

Vision transformers have achieved significant improvements on various vision tasks but their quadratic interactions between tokens significantly reduce computational efficiency. Many pruning methods have been proposed to remove redundant tokens for efficient vision transformers recently. However, existing studies mainly focus on the token importance to preserve local attentive tokens but completely ignore the global token diversity. In this paper, we emphasize the cruciality of diverse global semantics and propose an efficient token decoupling and merging method that can jointly consider the token importance and diversity for token pruning. According to the class token attention, we decouple the attentive and inattentive tokens. In addition to preserving the most discriminative local tokens, we merge similar inattentive tokens and match homogeneous attentive tokens to maximize the token diversity. Despite its simplicity, our method obtains a promising trade-off between model complexity and classification accuracy. On DeiT-S, our method reduces the FLOPs by 35% with only a 0.2% accuracy drop. Notably, benefiting from maintaining the token diversity, our method can even improve the accuracy of DeiT-T by 0.1% after reducing its FLOPs by 40%.

Prompt learning has become one of the most efficient paradigms for adapting large pre-trained vision-language models to downstream tasks. Current state-of-the-art methods, like CoOp and ProDA, tend to adopt soft prompts to learn an appropriate prompt for each specific task. Recent CoCoOp further boosts the base-to-new generalization performance via an image-conditional prompt. However, it directly fuses identical image semantics to prompts of different labels and significantly weakens the discrimination among different classes as shown in our experiments. Motivated by this observation, we first propose a class-aware text prompt (CTP) to enrich generated prompts with label-related image information. Unlike CoCoOp, CTP can effectively involve image semantics and avoid introducing extra ambiguities into different prompts. On the other hand, instead of reserving the complete image representations, we propose text-guided feature tuning (TFT) to make the image branch attend to class-related representation. A contrastive loss is employed to align such augmented text and image representations on downstream tasks. In this way, the image-to-text CTP and text-to-image TFT can be mutually promoted to enhance the adaptation of VLMs for downstream tasks. Extensive experiments demonstrate that our method outperforms the existing methods by a significant margin. Especially, compared to CoCoOp, we achieve an average improvement of 4.03% on new classes and 3.19% on harmonic-mean over eleven classification benchmarks.

Domain adaptation (DA) has recently made tremendous progress in remote sensing image scene classification. Particularly, open-set DA (OSDA) has attracted increasing attention, wherein the target domain includes unknown classes. However, existing OSDA methods assume that the source samples or the parameters of the source model are available, which is not practical due to concerns about digital privacy and portability issues. Addressing this, we investigate a more realistic and challenging open-set DA scenario for remote sensing image scene classification, where the unlabeled target domain is only provided with a black-box source predictor (i.e., only model predictions are accessible). To address this problem, we devise an Open-set Knowledge distillation framework with neighboRhood similarity regularization and uncertAinty modeling called OKRA. Specifically, we introduce a neighborhood similarity regularization to facilitate the open-set knowledge distillation (KD) using local neighborhood information. Furthermore, we propose an energy-based uncertainty modeling (UM) strategy for open-set recognition, which can effectively discriminate known and unknown target data without any thresholding. Empirical results on six cross-scene scenarios built from three datasets verify that OKRA is effective and practical for remote sensing image scene classification, outperforming existing data-dependent OSDA methods by a large margin.

The changing preferences of users towards items trigger the emergence of session-based recommender systems (SBRSs), which aim to model the dynamic preferences of users for next-item recommendations. However, most of the existing studies on SBRSs are based on long sessions only for recommendations, ignoring short sessions, though short sessions, in fact, account for a large proportion in most of the real-world datasets. As a result, the applicability of existing SBRSs solutions is greatly reduced. In a short session, quite limited contextual information is available, making the next-item recommendation very challenging. To this end, in this paper, inspired by the success of few-shot learning (FSL) in effectively learning a model with limited instances, we formulate the next-item recommendation as an FSL problem. Accordingly, following the basic idea of a representative approach for FSL, i.e., meta-learning, we devise an effective SBRS called INter-SEssion collaborativeRecommender neTwork (INSERT) for next-item recommendations in short sessions. With the carefully devised local module and global module, INSERT is able to learn an optimal preference representation of the current user in a given short session. In particular, in the global module, a similar session retrieval network (SSRN) is designed to find out the sessions similar to the current short session from the historical sessions of both the current user and other users, respectively. The obtained similar sessions are then utilized to complement and optimize the preference representation learned from the current short session by the local module for more accurate next-item recommendations in this short session. Extensive experiments conducted on two real-world datasets demonstrate the superiority of our proposed INSERT over the state-of-the-art SBRSs when making next-item recommendations in short sessions.

Recently, hashing methods have attracted more and more attentions for their effectiveness in large scale data search, e.g., images and videos data, etc. For different scenarios, unsupervised, supervised and semi-supervised hashing methods have been proposed. Especially, when semantic information is available, supervised hashing methods show better performance than unsupervised ones. In many practical applications, one sample usually has more than one label, which has been considered by multi-label learning. However, few supervised hashing methods consider such scenario. In this paper, we propose a Multi-label Least-Squares Hashing (MLSH) method for multi-label data hashing. It can directly work well on multi-label data; moreover, unlike other hashing methods which directly learn hashing functions on original data, MLSH first utilizes the equivalent form of CCA and Least-Squares to project original multi-label data into lower-dimensional space; then, in the lower-dimensional space, it learns the project matrix and gets final binary codes of data. MLSH is tested on NUS-WIDE and CIFAR-100 which are widely used for searching task. The results show that MLSH outperforms several state-of-the-art hashing methods including supervised and unsupervised methods.