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In Korea, most drivers equip their vehicles with a black box camera, used to estimate the speed of the vehicle in case of traffic accidents such as car-to-car collisions, single-car accidents, and car-to-pedestrian accidents. Traditionally, speed estimation using the camera video has been done by using the distance between the road lane, surrounding structures, etc.However, when the following vehicle collides with a stationary leading vehicle or barrier, and no road lanes or structures are visible around the driving path in the black box camera video of the following vehicle, the speed of the following vehicle could be just estimated according the deformations on the collided vehicles or objects.Therefore, in this study, when a vehicle collision occurs, a virtual parallel line is drawn between the leading vehicle and the following vehicle in the black box camera image of the following vehicle and analyzed geometrically to estimate the distance and the speed of the following vehicle.After the vehicle collision experiment, the speed was estimated using the method proposed in this study using the captured black box video. As a result, it was confirmed that the accuracy was high when the collision speed was low. So The method proposed in this study is expected to be used to estimate collision speed in the cases of low impact speed in the rear end collisions. more...

Video data received for analysis often come in a variety of file formats and compression schemes. These data are often transcoded to a consistent file format for forensic examination and/or ingesting into a video analytic system. The file format often requested is an MP4 file format. The MP4 file format is a very common and a universally accepted file format. The practical application of this transcoding process, across the analytical community, has generated differences in video quality. This study sought to explore possible origins of the differences and assist the practitioner by defining minimum recommendations to ensure that quality of the video data is maintained through the transcoding process. This study sought to generate real world data by asking participants to transcode provided video files to an MP4 file format using programs they would typically utilize to perform this task. The transcoded results were evaluated based on measurable metrics of quality. As the results were analyzed, determining why these differences might have occurred became less about a particular software application and more about the settings employed by the practitioner or of the capabilities of the program. This study supports the need for any video examiner who is transcoding video data to be cognizant of the settings utilized by the programs employed for transcoding video data, as loss of video quality can affect analytics as well as further analysis. [ABSTRACT FROM AUTHOR] more...

Korea has seen that the installation of CCTVs is becoming more common to control over-speeding vehicles, track fugitive vehicles, analyze accidents, and prevent crime. As CCTV becomes cheaper and its need is increasing to maintain public order and security, it is now widely distributed. When estimating a vehicle's speed through CCTV images, a vehicle's driving distance is measured by using road lanes or surrounding structures. The speed is then calculated by analyzing travel time. Furthermore, if there is no lane or structure in the section where vehicle speed is to be estimated, it is difficult to measure driving distance. Thus, estimating speed becomes difficult. Likewise, speed is estimated by using the cross-ratio method. However, when estimating vehicle speed by using cross-ratio in CCTV images, lens distortion and curve-section errors occur. Since it is difficult to use the cross-ratio method when the front and rear wheels are not visible at the same time in the video, this study is proposing a new method. The method of estimating vehicle speed as presented in this study is to estimate the speed of an accident vehicle by comparing the location and time of the accident vehicle and the test vehicle in the CCTV image after filming the test vehicle with CCTV at the accident site, while driving the test vehicle at the same trajectory as the accident vehicle at a constant speed. This method is expected to be used in actual events. more...

Unintended acceleration car accident which is hard to be regarded as human errors is examined. We investigated the accident car to determine the cause upon being requested to investigate by the police. From the car black box, we could narrow down the reason of the acceleration. As one of the causes of unintended acceleration we assumed that the restoration failure of the pedal interfered with by improper use of a floor mat and could reconstruct this. We discussed the acceleration values ​​of the accident vehicle and paid attention to the floor mat used in it. The results indicate that the negligible physical interference in the accelerator linkage could cause a devastating accident. more...

In various types of traffic accidents, including car-to-car crash, vehicle-pedestrian collision, and hit-and-run accident, driver overspeed is one of the critical issues of traffic accident analysis. Hence, analysis of vehicle speed at the moment of accident is necessary. The present article proposes a vehicle speed estimate method (VSEM) applying a virtual plane and a virtual reference line to a forensic video. The reliability of the VSEM was verified by comparing the results obtained by applying the VSEM to videos from a test vehicle driving with a global positioning system (GPS)-based Vbox speed. The VSEM verified by these procedures was applied to real traffic accident examples to evaluate the usability of the VSEM. [ABSTRACT FROM AUTHOR] more...

A Phase-Alternation Line (PAL) Mini Digital Video (MiniDV) recording and camcorder were provided by the Law Society of Singapore for forensic examination. During visual analyses of the submitted recording and a test recording produced on the submitted camcorder, the number of occurrences of each unique date/time stamp varied from the nominal value of 25 frames (the frame rate per second of PAL recordings), within a range of ±3 frames. This embedded date/time information is recorded in the digital bit stream along with the video and audio information and can be optionally displayed during playback. These visual observations prompted detailed analyses of the digital metadata of the recordings which consisted of locating the portions of the bit stream associated with the date/time information, and then identifying their redundancy characteristics, data structure, and encoding protocol. Automated scripts were developed using digital data analysis software to locate, extract, convert, and count all of the unique date/time stamps, and to provide an easily-viewable output of the results. The application of the scripting process to both the submitted tape and the test recording produced on the submitted camcorder revealed that the date/time information on each exhibited a nonstandard but consistent timing pattern, which confirmed the visual observations and provided evidence that the submitted recording was consistent with having been produced on the submitted camcorder. [ABSTRACT FROM AUTHOR] more...

Abstract: This article reports on the electric network frequency criterion as a means of assessing the integrity of digital audio/video evidence and forensic IT and telecommunication analysis. A brief description is given to different ENF types and phenomena that determine ENF variations. In most situations, to reach a non-authenticity opinion, the visual inspection of spectrograms and comparison with an ENF database are enough. A more detailed investigation, in the time domain, requires short time windows measurements and analyses. The stability of the ENF over geographical distances has been established by comparison of synchronized recordings made at different locations on the same network. Real cases are presented, in which the ENF criterion was used to investigate audio and video files created with secret surveillance systems, a digitized audio/video recording and a TV broadcasted reportage. By applying the ENF Criterion in forensic audio/video analysis, one can determine whether and where a digital recording has been edited, establish whether it was made at the time claimed, and identify the time and date of the registering operation. [Copyright &y& Elsevier] more...

We report the use of the geometric design standard for road markings published in the "Standard Details of Road Elements" ('SDRE') by the Land Transport Authority ('LTA') of Singapore as a convenient and sufficiently accurate means of estimating distances between features of the roadway, particularly useful for performing speed analysis based on videos. In this study, onsite measurements (by measuring tape, total station or 3D laser scanner) from various locations in Singapore, as well as the corresponding distances based on Google Earth Pro, were compared with those estimated using the SDRE. We demonstrate herein that the SDRE estimated 85.7% of all corresponding onsite measurements to within ±5%, and can thus be relied upon for crash reconstruction. This study also evaluated the distance accuracies associated with using the geometric design standard (the SDRE) and Google Earth Pro, and determined that both methods were robust and accurate, with overall average absolute percentage errors of less than 1% and would be beneficial for obtaining measurements for crash reconstruction, especially when the site of interest is not accessible. [ABSTRACT FROM AUTHOR] more...