Multi-modality image fusion (MIF) aims to integrate complementary information from diverse imaging modalities into a single comprehensive representation and serves as an essential processing step for downstream high-level computer vision tasks. The existing deep unfolding-based processes demonstrate promising results; however, they often rely on deterministic priors with limited generalization ability and usually decouple from the training process of object detection. In this paper, we propose Semantic-Aware Deep Unfolded Network with Diffusion Prior (SEND), a novel framework designed for transparent and effective multi-modality fusion and object detection. SEND consists of a Denoising Prior Guided Fusion Module and a Fusion Object Detection Module. The Denoising Prior Guided Fusion Module does not utilize the traditional deterministic prior but combines the diffusion prior with deep unfolding, leading to improved multi-modal fusion performance and generalization ability. It is designed with a model-based optimization formulation for multi-modal image fusion, which is unfolded into two cascaded blocks: a Diffusion Denoising Fusion Block to generate informative diffusion priors and a Data Consistency Enhancement Block that explicitly aggregates complementary features from both the diffusion priors and input modalities. Additionally, SEND incorporates the Fusion Object Detection Module with the Denoising Prior Guided Fusion Module for object detection task optimization using a carefully designed two-stage training strategy. Experiments demonstrate that the proposed SEND method outperforms state-of-the-art methods, achieving superior fusion quality with improved efficiency and interpretability.

Adversarial attacks on Graph Neural Networks (GNNs) have emerged as a significant threat to the security of graph learning. Compared with Graph Modification Attacks (GMAs), Graph Injection Attacks (GIAs) are considered more realistic attacks, in which attackers perturb GNN models by injecting a small number of fake nodes. However, most existing black-box GIA methods either require comprehensive knowledge of the dataset and the ground-truth labels or a large number of queries to execute the attack, which is often unfeasible in many scenarios. In this paper, we propose an unsupervised method for leveraging the rich knowledge contained in the graph data themselves to enhance the success rate of graph injection attacks on the initial query. Specifically, we introduce GraphContrastive Learning-based Graph Injection Attack (GCIA), which consists of a node encoder, a reward predictor, and a fake node generator. The Graph Contrastive Learning (GCL)-based node encoder transforms nodes for low-dimensional continuous embedding, the reward predictor acts as a simplified surrogate for the target model, and the fake node generator produces fake nodes and edges based on several carefully designed loss functions, utilizing the node encoder and reward predictor. Extensive results demonstrate that the proposed GCIA method achieves a first query success rate of 91.2% on the Reddit dataset and improves the success rate to over 99.7% after 10 queries.