Aggregating Layers for Deepfake Detection

Authors: Amir Jevnisek, Shai Avidan

Published: 2022-10-11 14:29:47+00:00

AI Summary

This paper addresses the challenge of Deepfake detection in a practical scenario where models are trained on one Deepfake algorithm but tested on others. The main contribution is an algorithm that aggregates features extracted across all layers of a backbone network to improve robustness and detection performance. This approach achieves state-of-the-art results for both Deepfake and synthetic image detection.

Abstract

The increasing popularity of facial manipulation (Deepfakes) and synthetic face creation raises the need to develop robust forgery detection solutions. Crucially, most work in this domain assume that the Deepfakes in the test set come from the same Deepfake algorithms that were used for training the network. This is not how things work in practice. Instead, we consider the case where the network is trained on one Deepfake algorithm, and tested on Deepfakes generated by another algorithm. Typically, supervised techniques follow a pipeline of visual feature extraction from a deep backbone, followed by a binary classification head. Instead, our algorithm aggregates features extracted across all layers of one backbone network to detect a fake. We evaluate our approach on two domains of interest - Deepfake detection and Synthetic image detection, and find that we achieve SOTA results.


Key findings
The proposed layer aggregation approach achieves state-of-the-art results for both synthetic image detection and cross-dataset Deepfake detection, demonstrating superior robustness and consistency (highest CoV-1 score). The method also provides an inherent analysis tool to identify which features and image regions contribute most to detecting specific manipulations, and enables significant network trimming with minimal performance degradation.
Approach
The proposed approach aggregates features extracted from all layers of a backbone network. Each layer's feature tensor is processed through average pooling and a multi-layered perceptron to produce a set of 'primitives.' These primitives from all layers are then concatenated and fed into a simple linear regression model to output the final binary classification score for detecting fakes.
Datasets
FaceForensics++, CelebA-HQ, FFHQ (Flickr-Faces-HQ). Generative models used for synthetic data creation include PGAN, StyleGAN, StyleGAN2, Glow, and GMMs.
Model(s)
EfficientNet-V2-Small (as backbone), Xception (with and without layer aggregation), Linear Regression model (for the classification head).
Author countries
Israel