Video camouflaged object detection (VCOD) aims to identify objects that seamlessly blend into their surroundings in video sequences. Traditional methods merely rely on visual cues to capture inter-frame motion that reveals camouflaged objects. However, the high similarity between camouflaged objects and their environments often renders pure reliance on visual cues unreliable. Additionally, random motions including camera shaking and abrupt scene transitions also inevitably bring noise into the identification process. To overcome these challenges, we propose a Motion Reasoning Chain Network (MRCNet), a novel cross-modal VCOD framework that emulates the human thought process when observing camouflaged objects, i.e., motion reasoning. Specifically, we introduce a generative sampling strategy grounded in multimodal large language models (MLLMs) to bridge the implicit knowledge space of MLLMs and the explicit representation space regarding the attributes of camouflaged objects, thereby enabling the effective establishment of the motion reasoning chain tailored for VCOD. This process provides semantic guidance for visual comprehension of camouflaged objects through motion and concept attribute reasoning. To improve the identification capability of camouflaged objects, we develop motion representation learning driven by the motion reasoning chain. It introduces hierarchical de-biased motion prototype learning to mitigate hallucinations of MLLMs, boosting the motion perception. To learn precise prompts for the visual foundation model, cross-modal prompt learning further incorporates the de-biased concept prototype into visual representations to enhance the visual comprehension of camouflaged objects. Extensive experiments across three datasets demonstrate that MRCNet achieves state-of-the-art results on both general metrics and spatiotemporal consistency metrics.

Graph condensation (GC) aims to distill the original graph into a small-scale graph, mitigating redundancy and accelerating GNN training. However, conventional GC approaches heavily rely on rigid GNNs and task-specific supervision. Such a dependency severely restricts their reusability and generalization across various tasks and architectures. In this work, we revisit the goal of ideal GC from the perspective of GNN optimization consistency, and then a generalized GC optimization objective is derived, by which those traditional GC methods can be viewed nicely as special cases of this optimization paradigm. Based on this, \textbf{Pre}-trained \textbf{G}raph \textbf{C}ondensation (\textbf{PreGC}) via optimal transport is proposed to transcend the limitations of task- and architecture-dependent GC methods. Specifically, a hybrid-interval graph diffusion augmentation is presented to suppress the weak generalization ability of the condensed graph on particular architectures by enhancing the uncertainty of node states. Meanwhile, the matching between optimal graph transport plan and representation transport plan is tactfully established to maintain semantic consistencies across source graph and condensed graph spaces, thereby freeing graph condensation from task dependencies. To further facilitate the adaptation of condensed graphs to various downstream tasks, a traceable semantic harmonizer from source nodes to condensed nodes is proposed to bridge semantic associations through the optimized representation transport plan in pre-training. Extensive experiments verify the superiority and versatility of PreGC, demonstrating its task-independent nature and seamless compatibility with arbitrary GNNs.

The Segment Anything Model (SAM), a prompt-driven foundational model, has demonstrated remarkable performance in natural image segmentation. However, its application in video camouflaged object detection (VCOD) en-counters challenges, chiefly stemming from the overlooked temporal-spatial associations and the unreliability of user-provided prompts for camouflaged objects that are difficult to discern with the naked eye. To tackle the above issues, we endow SAM with keen eyes and propose the Temporal-spatial Prompt SAM (TSP-SAM), a novel approach tailored for VCOD via an ingenious prompted learning scheme. Firstly, motion-driven self-prompt learning is employed to capture the camouflaged object, thereby bypassing the need for user-provided prompts. With the detected subtle motion cues across consecutive video frames, the overall movement of the camouflaged object is captured for more precise spa-tial localization. Subsequently, to eliminate the prompt bias resulting from inter-frame discontinuities, the long-range consistency within the video sequences is taken into account to promote the robustness of the self-prompts. It is also injected into the encoder of SAM to enhance the representational capabilities. Extensive experimental results on two benchmarks demonstrate that the proposed TSP-SAM achieves a significant improvement over the state-of-the-art methods. With the mIoU metric increasing by 7.8% and 9.6%, TSP-SAM emerges as a groundbreaking step forward in the field of VCOD.

Video camouflaged object detection aims to identify objects that are visually concealed within the surroundings in a video. Most of the existing methods fall into analyzing the implicit inter-frame motion to capture the camouflaged object. However, due to a lack of exploring the prior explicit motion of the camouflaged object, these works generally encounter difficulty in capturing the complete camouflaged object. To address this issue, we propose to integrate implicit and explicit motion learning into a unified framework, namelyImplicit-Explicit Motion Learning network (IMEX), for video camouflaged object detection. Specifically, to promote the identifiability of the camouflaged object, a cross-scale representation fusion was proposed for global inter-frame alignment. By establishing cross-scale temporal-spatial association and aggregating the temporal-spatial attentive representations, it also achieves an elimination of the implicit motion of inter-frame to some extent. Moreover, to further improve the discriminability of boundary regions of the detected object, an explicit motion-induced consistency preserving of camouflaged objects is proposed, in which the prior boundary-aware explicit motion field is leveraged to supervise the consistency of camouflaged objects in consecutive frames. Extensive experiments show that our proposed IMEX achieves substantial performance improvements by a large margin.

Weakly supervised object localization exploits the last convolutional feature maps of classification model and the weights of Fully-Connected (FC) layer to achieves localization. However, high-level feature maps for localization lack edge features. Additionally, the weights are specific to classification task, causing only discriminative regions to be discovered. In order to fuse edge features and adjust the attention distribution for feature map channels, we propose an efficient method called Attention-based Dual-Branches Localization (ADBL) Network, in which dual-branches structure and attention mechanism are adopted to mine edge features and non-discriminative features for locating more target areas. Specifically, dual-branches structure cascades low-level feature maps to mine target object edge regions. Additionally, during inference stage, attention mechanism assigns appropriate attention for different features to preserve non-discriminative areas. Extensive experiments on both ILSVRC and CUB-200-2011 datasets show that the ADBL method achieves substantial performance improvements.