Restoring nighttime images affected by multiple adverse weather conditions is a practical yet under-explored research problem, as multiple weather degradations usually coexist in the real world alongside various lighting effects at night. This paper first explores the challenging multi-weather nighttime image restoration task, where various types of weather degradations are intertwined with flare effects. To support the research, we contribute the AllWeatherNight dataset, featuring large-scale nighttime images with diverse compositional degradations. By employing illumination-aware degradation generation, our dataset significantly enhances the realism of synthetic degradations in nighttime scenes, providing a more reliable benchmark for model training and evaluation. Additionally, we propose ClearNight, a unified nighttime image restoration framework, which effectively removes complex degradations in one go. Specifically, ClearNight extracts Retinex-based dual priors and explicitly guides the network to focus on uneven illumination regions and intrinsic texture contents respectively, thereby enhancing restoration effectiveness in nighttime scenarios. Moreover, to more effectively model the common and unique characteristics of multiple weather degradations, ClearNight performs weather-aware dynamic specificity and commonality collaboration that adaptively allocates optimal sub-networks associated with specific weather types. Comprehensive experiments on both synthetic and real-world images demonstrate the necessity of the AllWeatherNight dataset and the superior performance of ClearNight.

Substitute training-based data-free black-box attacks pose a significant threat to enterprise-deployed models. These attacks use a generator to synthesize data and query APIs, then train a substitute model to approximate the target model's decision boundary based on the returned results. However, existing attack methods often struggle to produce sufficiently diverse data, particularly for complex target models and extensive target data domains, severely limiting their practical application. To address this gap, we design domain-augmented learning to improve the quality of the synthetic data domain (SDD) generated by the generator from two perspectives. Specifically, (1) To broaden the SDD's coverage, we introduce textual semantic embeddings into the generator for the first time. (2) For enhancing the SDD's discretization, we propose a competitive optimization strategy that forces the generator to self-compete, along with heterogeneity excitation to overcome the constraints of information entropy on diversity. Comprehensive experiments demonstrate that our method is more effective. In non-targeted attacks on the CIFAR-10 and Tiny-ImageNet datasets, our method outperforms the state-of-the-art by 14% and 7% in attack success rate, respectively.

Self-supervised learning is widely applied across various domains due to its advantage of learning data representations without the need for labels. However, recent research shows that backdoor attacks on self-supervised learning are achievable by coupling benign features with trigger features without manipulating labels. Existing methods, however, suffer from poor trigger disguise. When designing triggers, more emphasis is placed on attack strength rather than on disguising the triggers, which makes these triggers easily detectable through manual inspection or preprocessing methods. Therefore, we propose a camouflaged self-supervised backdoor attack method from the perspective of visual disguise. Specifically, we design triggers by embedding variable adverse weather information to achieve visual camouflage, which can bypass certain defence methods to some extent. Additionally, since our proposed camouflaged triggers have a global nature, they achieve more efficient backdoor attack capabilities. Experiments demonstrate that our method achieves attack success rates of 83.4% on the CIFAR-100 dataset and 44.8% on the ImageNet-100 dataset, surpassing existing state-of-the-art methods by 14.6% and 24.4%, respectively. At the same time, our method exhibits better stealthiness.

In multi-organ segmentation, attention mechanisms are frequently employed to enhance the focus on irregular organs, improving performance. However, current attention mechanisms exhibit notable limitations. On the one hand, their visual saliency-based attention bias results in incomplete region-of-interest coverage. On the other hand, their organ-specific cognitive deficiency exacerbates organ misclassification. Inspired by neurocognitive science, this paper proposes a Cognitive Comprehension Attention (CCA). Diverging from existing methods, CCA achieves refined attention allocation by decomposing visual representations into discrete visual stimuli. This fine-grained approach enables unbiased processing for each visual stimulus, preventing critical information omission and ensuring comprehensive organ region coverage. More importantly, CCA generates organ-specific attention representations by establishing distinct attention patterns across different organ regions, which empowers CCA with cognitive capacity, resolving organ misclassification. Extensive experiments across multiple datasets demonstrate that CCA significantly enhances backbone performance, achieving a max mDice improvement of 8.45% while surpassing state-of-the-art methods by 9% in Recall and 11.78% in Precision. Code is available at:https://github.com/robert1818118/CCA.

Digital image forensics aims to verify the authenticity of digital images, which has emerged as a prominent research area. To reveal the manipulation history of an image, the existing methods can only detect specific image operations or are based on a general forensic feature with high dimensions. Moreover, these methods perform well only when the operation chain length is no greater than 2. However, their detection accuracy drops significantly for images with longer operation chains that are more representative of real-world scenarios. To break these limitations, we proposed a novel forensics frequency Feature based on Histogram and Detail Map (FHDM(79D)), which can distinguish various operation chains containing different numbers of operations. Specifically, compared to the traces left by image manipulation in the spatial domain, we have discovered that they are more distinct in the frequency domain. This observation has prompted us to extract features from the frequency domain of images by analyzing their histograms and detail maps to capture the manipulation traces of the images. Notably, the proposed feature extracted in the frequency domain has almost 90% fewer dimensions than the commonly used general forensic features, such as SRM(714D), which greatly reduces the computational complexity. Meanwhile, compared to deep learning-based methods, the experiments show that the proposed method achieves a detection accuracy of over 95% for image operations across multiple datasets, while other deep learning-based methods do not exceed 90% accuracy. Extensive experimental results show that the proposed method is more versatile and effective, showing good performance in complex operation chain detection and local forgery detection. The code is available at https://github.com/CherishL-J/Op-detection.

Few-shot semantic segmentation (FSS) is of tremendous potential for data-scarce scenarios, particularly in medical segmentation tasks with merely a few labeled data. Most of the existing FSS methods typically distinguish query objects with the guidance of support prototypes. However, the variances in appearance and scale between support and query objects from the same anatomical class are often exceedingly considerable in practical clinical scenarios, thus resulting in undesirable query segmentation masks. To tackle the aforementioned challenge, we propose a novel prototype-guided graph reasoning network (PGRNet) to explicitly explore potential contextual relationships in structured query images. Specifically, a prototype-guided graph reasoning module is proposed to perform information interaction on the query graph under the guidance of support prototypes to fully exploit the structural properties of query images to overcome intra-class variances. Moreover, instead of fixed support prototypes, a dynamic prototype generation mechanism is devised to yield a collection of dynamic support prototypes by mining rich contextual information from support images to further boost the efficiency of information interaction between support and query branches. Equipped with the proposed two components, PGRNet can learn abundant contextual representations for query images and is therefore more resilient to object variations. We validate our method on three publicly available medical segmentation datasets, namely CHAOS-T2, MS-CMRSeg, and Synapse. Experiments indicate that the proposed PGRNet outperforms previous FSS methods by a considerable margin and establishes a new state-of-the-art performance.

The key that hinders the performance improvement of current camouflaged object detection (COD) models is the lack of discriminability of features at fine granularity. We solve this problem from two complementary perspectives. Firstly, complex scenes result in the discriminative feature representations of camouflaged objects being present at different scales and semantic abstraction levels. Therefore, a mechanism is needed to increase the diversity of features to integrate more information potentially beneficial for COD. Second, appearance similarity between objects and environments will inevitably lead to similarity in features. Enhancing feature diversity alone is not enough to solve the above problems. Therefore, it is necessary to give the model semantic perception capabilities to expand the subtle discrepancies between objects and environments in feature embedding. Inspired by the first point, we propose a cross-scale interaction module (CSIM) that utilizes cross-attention between different scales to enhance the diversity of feature representations. Regarding the second point, the semantic guided feature learning (SGFL) is proposed to promote the model to expand feature discrepancies through explicit supervision. Experiments on four popular COD datasets show that our method outperforms recent SOTA methods. In addition, polyp segmentation experiments show that it is also effective for other COD-like tasks.

Recent substitute training methods have utilized the concept of Generative Adversarial Networks (GANs) to implement data-free black-box attacks. Specifically, in designing the generators, the substitute training methods use a similar structure to the generators in GANs. However, this design approach ignores the potential situation that the generators in GANs operate under real data supervision, while the generators in substitute training methods lack such supervision. This difference in data-supervised conditions constrain the diversity of data generated by the substitute training methods, resulting in inadequate data to support effective training of the substitute model. This impacts the substitute model's ability to attack the target model further. Consequently, to solve the above issues, we propose three strategies to improve the attack success rates. For the generator, we first propose a dense projection space that projects the input noise into various latent feature spaces to diversify feature information. Then, we introduce a novel disguised natural color mode. This mode improves information exchange between the generator's output layer and previous layers, allowing for more diverse generated data. Besides, we present a regularization method for the substitute model, called noise-based balanced learning, to prevent the potential risk of overfitting due to the lack of diversity of the generated data. In the experimental analysis, extensive experiments are conducted to validate the effectiveness of these proposed strategies.

Image manipulation detection methods typically rely on a binary annotation called Primary Labeling (PrLa) to identify tampered and authentic regions in a tampered image. However, PrLa only focuses on the difference between authentic and tampered regions, ignoring the distinctions among tampered regions in different images. This transforms the task of image manipulation detection into salient object detection, with the goal shifting towards identifying the most attention-grabbing objects in images. To address this issue, this paper proposes a novel labeling strategy called Secondary Labeling (SeLa). SeLa generates a query table containing multiple tampered categories and randomly reassigns these tampered classes to different types of tampered data, effectively improving the detection performance of models by refocusing the differences among the various data. Additionally, to further improve the detection performance, this paper introduces an Adaptive Label Smoothing (ALS) regularization method. This method addresses the loss of correlation among tampered classes in SeLa caused by the one-hot encoding method. Experimental results show that compared with PrLa, SeLa not only improves the performance of detection models by up to 17%, but also enhances the robustness and convergence rate.

Color invariance is critical for computer vision systems since it significantly increases the robustness and effectiveness of the system. MSDA approaches (e.g., FMix and CutMix) have attracted considerable attention in recent years since they are simple, effective, and do not require extra computation con-sumption. By mixing samples, these approaches extend the distribution of training samples. However, the color information of these mixed samples is not changed, which makes it still difficult for trained models to achieve color invariance. To address this issue, we propose a universal module called Mixed Color Channels (MCC) that implements color changes by mixing the sample and its color variants, which enables trained models to achieve color invariance. In the experimen-tal section, we insert MCC into four state-of-the-art MSDA approaches, evaluate its effectiveness, and embed MCC into a non-MSDA method to demonstrate its extensibility.

With the popularity of image editing tools, the originality and information security of images are facing serious threats. The most common threat is splicing forgery that copies a part of the area from one donor image to the acceptor one. Some research works were proposed to protect the image originality, whereas they are still difficult to apply in practice. There are two main reasons: (a) very limited data for learning models; (b) huge attribute differences between the donor and acceptor images. We propose two novel tasks to conquer the above challenges: Synthetic Adversarial Networks (SANs) and Hybrid Dense U-Net (HDU-Net). SAN finds the most secluded position for inserting tampered areas in an image by learning the association between scenes and objects, and can enlarge the original small data set by more than 40 times. We call the data set SF-Data generated by SAN. We combine the dense U-Net that detects the differences of the essential attributes of image with four spaces containing more available feature information to propose HDU-Net. Then, the synthetic data set SF-Data are used to train HDU-Net. We perform various attack experiments on several public data sets to demonstrate the effectiveness and robustness of our method.

The guarantee of social stability comes from many aspects of life, and image information security as one of them is being subjected to various malicious attacks. As a means of information attack, image splicing forgery refers to copying some areas of an image to another image to hide the traces of the original information and leads to grave consequences. Image splicing forgery is extremely complex since the attributes of the two images subjected to the pasting and copying operations are greatly different. In order to solve the issue mentioned above, we propose a method by applying a neural learning network controlled by multiple scales (MCNL-Net) based on U-Net to identify whether an image has been tampered and to locate the tampered regions. Firstly, the learning capacity of MCNL-Net is enhanced by the combination of a residual propagation module and a residual feedback module. An ingenious strategy is designed to control the size of local receptive field in each building block of MCNL-Net. The strategy makes MCNL-Net able to achieve properties and superiorities of multi-scale structure and learn specified features. For further improving the detection performance of MCNL-Net, a block attention mechanism is proposed to control the advanced degree of the input information in each building block. In addition, a MaxBlurPool method is applied into image splicing forgery detection for the first time, preserving the shift-equivariance of a convolutional neural network. Through experiments, we demonstrate that MCNL-Net can achieve more promising results and offer stronger robustness than the state-of-the-art splicing forgery detection methods.