Forgery detection of motion compensation interpolated frames based on discontinuity of optical flow

Abstract

Motion Compensated Frame Interpolation (MCFI), a frame-based video operation to increase the motion continuity of low frame rate video, can be adopted by falsifiers for forging high bitrate video or splicing videos with different frame-rates. For existing MCFI detectors, their performance are degraded by stronger video compression, and noise. To deal with this problem, we propose a blind forensics method to detect the adopted MCFI operation. After investigating the synthetic process of interpolated frames, we discover that motion regions of interpolated frames exist some local slight artifacts, causing the optical flow based inter-frame discontinuity. To capture this irregularities introduced by various MCFI techniques, compact features are designed, which are calculated as Temporal Frame Difference-weighted histogram of Local Binary Pattern computed on Optical Flow field (TFD-OFLBP). Meanwhile, Local Inter-block and Edge-block difference Features (LIEF) are further proposed to detect interpolation frames with stable content. Besides, a set of forensics tools are adopted to eliminate the side effects of possible interferences of the scenes change, sudden lighting change, focus vibration, and some original frames with inherent local artifacts. Experimental results on four representative MCFI software and techniques show that the proposed approach outperforms existing MCFI detectors and also with robustness to compression, and noise.