Vehicle Speed Measurement Methodology Robust to Playback Speed-Manipulated Video File

Kyu-Sun Shim,Heejo Lee,Nam In Park,Jin-Hwan Kim,Oc-Yeub Jeon

doi:10.1109/access.2021.3115500

Kyu-Sun Shim, Heejo Lee + Show 3 more

Open Access

https://doi.org/10.1109/access.2021.3115500

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Abstract

Concomitant with the virtual ubiquity of dashcams in vehicles, the instantaneous speed of vehicles during accidents can now be measured using dashcam videos to understand the causes of such accidents. In this study, we estimated vehicle speeds using dashcam videos recorded in various road environments and analyzed them by comparing them to ground truth. We also considered various scenarios yielding retaken and re-encoded videos from additional recording devices, depending on the circumstances, wherein the original video can be manipulated in terms of playback speed and/or frames per second. The experimental results revealed that the actual and measured speeds were similar for most user-specific intervals. Moreover, the results suggest that our estimated speed is adequately valid as evidence, regardless of retake and re-encoding states. Furthermore, we adopted a statistical approach (i.e., Pearson’s correlation coefficient analysis) to verify the proposed vehicle speed estimation method. The results showed that when playback speed was manipulated in re-encoded or retaken video, the proposed method consistently measured speeds at 99.99 % accuracy. This verified method will play an important role in deriving reliable results from various evidential video sources.

Highlights

Upon the occurrence of a traffic accident, the speed of the vehicle prior to collision is considered as important for determining the root cause of the accident and for investigating the responsibilities among interested parties [1]
In this paper we provide a robust method of accurately measuring vehicle speeds from dashcam video, even when manipulated
DETECTION PHASE During this step, the playback speed is detected using the time information recorded in the video based on the fact that the time information of the dashcam device is recorded in the general video

Summary

INTRODUCTION

Upon the occurrence of a traffic accident, the speed of the vehicle prior to collision is considered as important for determining the root cause of the accident and for investigating the responsibilities among interested parties [1]. This study proposes a robust methodology that can accurately measure vehicle speeds regardless of the edited playback speed, frames per second (fps), etc. In this paper we provide a robust method of accurately measuring vehicle speeds from dashcam video, even when manipulated. OVERVIEW In this paper, we propose a method that can robustly measure vehicle speeds from dashcam video while considering the video’s manipulation in various situations (i.e., types 1, 2, and 3). The proposed method comprises a detection phase that determines whether the playback speed of the video is altered, and an estimation phase that calibrates and measures the speed from the previous step. · Estimation Phase: Measurement of the actual speed of the vehicle using the dashcam video based on the playback speed detected in the previous phase. The average value of the minimum and maximum speed can be derived as savg: smin dmin tmax

EXPERIMENTAL EVALUATION

3) RESULT OF HIGHWAY ENVIRONMENT

Findings

CONCLUSION