We present Deep-Check v3, a presentation attack detection system achieving AUC=1.0000 and EER=0.04% on the 140K Real vs Fake benchmark (20,000 test images) with Test-Time Augmentation. The architecture combines EfficientNet-B4 (1792-dim) with a novel multi-scale Laplacian frequency branch (FrequencyBranchV2, 48-dim) operating at three spatial scales (32x32, 64x64, 128x128), trained with focal BCE and supervised contrastive learning on six public datasets (~155K images). Cross-domain AUC=1.0000 on the held-out RVF10K dataset demonstrates strong generalization. The 70MB ONNX model runs entirely in-browser via WebAssembly, enabling privacy-preserving inference. Code available at https://github.com/paulrod0/deep-check
Pablo López Rodríguez (Mon,) studied this question.