Analysis of Rolling Shutter Effect on ENF-Based Video Forensics

Vatansever, Saffet; Dirik, Ahmet Emir; Memon, Nasir

doi:10.1109/tifs.2019.2895540

“…Such sensors employ a rolling shutter mechanism, which acquires a row at a time in each video frame [3,30]. A comprehensive analysis of the rolling shutter effect was conducted in [31]. An analytical model for videos captured using a rolling shutter mechanism was developed, demonstrating the relation between ENF variations and the idle period length.…”

Section: Introductionmentioning

confidence: 99%

An Automated Approach for Electric Network Frequency Estimation in Static and Non-Static Digital Video Recordings

Karantaidis

¹

,

Kotropoulos

²

2021

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Electric Network Frequency (ENF) is embedded in multimedia recordings if the recordings are captured with a device connected to power mains or placed near the power mains. It is exploited as a tool for multimedia authentication. ENF fluctuates stochastically around its nominal frequency at 50/60 Hz. In indoor environments, luminance variations captured by video recordings can also be exploited for ENF estimation. However, the various textures and different levels of shadow and luminance hinder ENF estimation in static and non-static video, making it a non-trivial problem. To address this problem, a novel automated approach is proposed for ENF estimation in static and non-static digital video recordings. The proposed approach is based on the exploitation of areas with similar characteristics in each video frame. These areas, called superpixels, have a mean intensity that exceeds a specific threshold. The performance of the proposed approach is tested on various videos of real-life scenarios that resemble surveillance from security cameras. These videos are of escalating difficulty and span recordings from static ones to recordings, which exhibit continuous motion. The maximum correlation coefficient is employed to measure the accuracy of ENF estimation against the ground truth signal. Experimental results show that the proposed approach improves ENF estimation against the state-of-the-art, yielding statistically significant accuracy improvements.

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“…The similarity in the observations between ENF signals extracted from simultaneously recorded signals has motivated one of the early proposed ENF-based forensics applications: using the ENF traces to authenticate or identify the time-ofrecording of a signal [1]. Other proposed ENF-based applications include detection of tampering/modification in a media signal [7]- [10] [11], multimedia synchronization [12], [13], characterizing the video camera producing an ENF-containing video [14], and determining the location-of-recording among different grids [15], [16]. Being able to tell the grid-location of recording of a media signal containing ENF traces across grids naturally leads to the question of whether we can pinpoint the location of recording of the media signal within a grid, i.e., an intra-grid localization.…”

Section: Introductionmentioning

confidence: 99%

Feasibility Study on Intra-Grid Location Estimation Using Power ENF Signals

Garg¹,

Hajj-Ahmad²,

Wu³

2021

Preprint

2

0

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<div>The Electric Network Frequency (ENF) is a signature of power distribution networks that can be captured by multimedia recordings made in areas where there is electrical activity. This has led to an emergence of several forensic applications based on the use of the ENF signature. Examples of such applications include estimating or verifying the time-of-recording of a media signal and inferring the power grid associated with the location in which the media signal was recorded. In this paper, we carry out a feasibility study to examine the possibility of using embedded ENF traces to pinpoint the location-of-recording of a signal within a power grid. In this study, we demonstrate that it is possible to pinpoint the location-of-recording to a certain geographical resolution using power signal recordings containing strong ENF traces. To this purpose, a high-passed version of an ENF signal is extracted and it is demonstrated that the correlation between two such signals, extracted from recordings made in different geographical locations within the same grid, decreases as the distance between the recording locations increases. We harness this property of correlation in the ENF signals to propose trilateration based localization methods, which pinpoint the unknown location of a recording while using some known recording locations as anchor locations. We also discuss the challenges that need to be overcome in order to extend this work to using ENF traces in noisier audio/video recordings for such fine localization purposes.</div>

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“…The similarity in the observations between ENF signals extracted from simultaneously recorded signals has motivated one of the early proposed ENF-based forensics applications: using the ENF traces to authenticate or identify the time-ofrecording of a signal [1]. Other proposed ENF-based applications include detection of tampering/modification in a media signal [7]- [10] [11], multimedia synchronization [12], [13], characterizing the video camera producing an ENF-containing video [14], and determining the location-of-recording among different grids [15], [16]. Being able to tell the grid-location of recording of a media signal containing ENF traces across grids naturally leads to the question of whether we can pinpoint the location of recording of the media signal within a grid, i.e., an intra-grid localization.…”

Section: Introductionmentioning

confidence: 99%

Feasibility Study on Intra-Grid Location Estimation Using Power ENF Signals

Garg¹,

Hajj-Ahmad²,

Wu³

2021

Preprint

2

0

View full text Add to dashboard Cite

<div>The Electric Network Frequency (ENF) is a signature of power distribution networks that can be captured by multimedia recordings made in areas where there is electrical activity. This has led to an emergence of several forensic applications based on the use of the ENF signature. Examples of such applications include estimating or verifying the time-of-recording of a media signal and inferring the power grid associated with the location in which the media signal was recorded. In this paper, we carry out a feasibility study to examine the possibility of using embedded ENF traces to pinpoint the location-of-recording of a signal within a power grid. In this study, we demonstrate that it is possible to pinpoint the location-of-recording to a certain geographical resolution using power signal recordings containing strong ENF traces. To this purpose, a high-passed version of an ENF signal is extracted and it is demonstrated that the correlation between two such signals, extracted from recordings made in different geographical locations within the same grid, decreases as the distance between the recording locations increases. We harness this property of correlation in the ENF signals to propose trilateration based localization methods, which pinpoint the unknown location of a recording while using some known recording locations as anchor locations. We also discuss the challenges that need to be overcome in order to extend this work to using ENF traces in noisier audio/video recordings for such fine localization purposes.</div>

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Analysis of Rolling Shutter Effect on ENF-Based Video Forensics

Cited by 35 publications

References 20 publications

An Automated Approach for Electric Network Frequency Estimation in Static and Non-Static Digital Video Recordings

An Automated Approach for Electric Network Frequency Estimation in Static and Non-Static Digital Video Recordings

Feasibility Study on Intra-Grid Location Estimation Using Power ENF Signals

Feasibility Study on Intra-Grid Location Estimation Using Power ENF Signals

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