VortiFlow: curl-based block-wise motion dynamics for frame-level video forgery detection, localization, and forgery type classification
摘要
The variety of cameras, frame rates, and motion patterns in real-world videos makes it difficult to detect frame-level tampering. This study presents a unified, training-free, three-stage framework to detect, localize, and classify inter-frame forgery in digital videos. Instead of using fixed thresholds, the proposed framework employs frames-per-second (FPS)-adaptive thresholding, enabling reliable operation across mobile, CCTV, and high-FPS videos. Stage 1 uses curl-based motion magnitude and a coefficient-of-variation model to identify anomalies; Stage 2 employs z-score modeling for block-wise rotational motion analysis; and Stage 3 uses geometric moments and sliding-window pattern alignment to classify different types of forgeries. The framework achieves average detection accuracy, precision, recall, F1-score, and localization accuracy of 97.43%, 97.48%, 99.09%, 98.27%, and 96.73%, respectively, across five datasets comprising three public datasets and two datasets generated using the proposed forgery-generation framework, demonstrating consistent cross-dataset performance. In addition to providing a reliable, interpretable, and computationally efficient forensic framework, comparative analysis shows how the proposed framework addresses important research gaps.