A Study on the Shutter Time of a Surveillance Camera to Improve Speed Detection Accuracy of Vehicles on Highways and Inner-City Streets

Detection of vehicle speed based on image processing technology recently has been found in many applications over the world. However, the accuracy of those methods has not been investigated taking into account of physical characteristics of the surveillance camera. Based on the operation time of the camera's optical sensor system including shutter time (ST) and sensor operating time, the accuracy of vehicle speed detection on highways as well as inner city streets can be significantly improved. The operation time of the camera’s sensor is essential for determination of frames over time in a vehicle surveillance system. Therefore, control of the shutter time ST will help a camera-based speed detection system to achieve much better accuracy.

Institutional Metadata and the Problem of Context

The traditional archive catalogue constitutes a form of structural and descriptive metadata that long precedes the internet; and the cataloguing of photographs is just one part of a process of archival administration. The application of keywords to images contrasts with archival prose description, which is based on the visual content of the image and is predominantly context-free; a remediation of the image itself. At the heart of this lies the notion that the single photograph is itself devoid of context; it is a discrete embodiment of shutter time and there is nothing certain either side of that. Thus, one can only speculate at its context, and institutional description techniques actively avoid such speculation. Yet context in the archive is ever-present and key to the function of images as objects of information and evidence. It is built through static relationships, through the situating of photographs in accordance with the concept of original order, and it is replicated through storage systems and hierarchical catalogue entries. Such orders, hierarchies and relationships are absent within sets of images that are brought together by keyword search, including through the websites of archival institutions that struggle to reconcile archival principles and identity with network culture. Images are transported to places where contextual information is at best difficult to access, especially for those unfamiliar with archival interfaces. In contrast to the controlled stasis of archival storage and interconnected recordkeeping systems, network storage is messy, unstable and poorly described. However, we must accept that context is not a prerequisite for many users, and for them the networking of archival images denotes a freedom; a democratisation of the archive. But in a media-driven society that is becoming more and more indifferent to the evidential value of documents of any kind, the context-free image is left predisposed to exploitation.