IDCNet: Image Decomposition and Cross-View Distillation for Generalizable Deepfake Detection

Existing deepfake detectors predominantly process entire facial images as input, which limits their sensitivity to local forgery cues due to representation bias and information loss through CNN feature aggregation. To address these limitations, we propose IDCNet, a novel deepfake detection framework based on image decomposition and cross-view distillation. Our key insight is that decomposing images into complementary views enables specialized processing of global and local forgery cues, while cross-view distillation facilitates their mutual enhancement. Specifically, the framework employs a lightweight U-Net generator with a dual-objective mechanism to decompose input images into global content and local detail views, optimized through reconstruction and classification losses. A cross-view distillation strategy is then applied to enhance complementary feature learning between views. Furthermore, to integrate local artifact information into existing detection models without architectural modifications, we propose a feature alignment method. Extensive experiments across 14 forgery methods demonstrate the effectiveness of our approach, achieving up to 4.4% AUC improvement on the CDFV2 dataset compared to state-of-the-art methods. The source code is available at: https://github.com/ wangzhiyuan120/idcnet.