Self-Anchored Progressive Framework With Noise Mitigation for Unsupervised Camouflaged Object Detection

Unsupervised Camouflaged Object Detection (UCOD) presents a significant challenge due to the inherent similarity between camouflaged objects and their backgrounds, compounded by the absence of manual annotations. Although pixel-level pseudo-labeling has proven effective for unsupervised salient object detection (USOD), it is far less reliable for COD, where the concealed and ambiguous nature of camouflaged objects frequently produces noisy pseudo-labels, causing misjudgments, missed detections, and imprecise boundaries. To overcome this, we propose SAPNet, a novel self-anchored progressive framework for UCOD. Rather than depending on noisy pixel-level supervision, we leverage semantically reliable foreground and background regions as high-confidence anchors. This effectively transforms the unsupervised problem into a more robust weakly supervised paradigm, reducing learning difficulty and mitigating overfitting to noise. SAPNet learns camouflaged objects progressively by first emphasizing these confident regions and then exploiting DINO's contextual awareness to recover complete structures. Central to our framework is the semantic-driven region detector (SDRD), which employs cascaded convolutions and a residual attention projection mechanism to suppress background noise, filter erroneous information, and enhance spatial context, ensuring reliable supervision signals. Furthermore, a region-based context inference module (RCIM) is introduced to iteratively refine object boundaries by integrating multi-level semantic features under the guidance of these refined region-level anchors. Extensive experiments on four benchmark COD datasets demonstrate that SAPNet significantly outperforms state-of-the-art unsupervised methods. The source code of our SAPNet is available at https://github.com/ArloJie/SAPNet.