Craig Howie, Commercial Director of Visimetrics says, “Following the London bombings in July 2005, the Metropolitan Police Service reviewed over 100,000 hours of CCTV footage as part of their incident investigation. This process consumed a huge amount of operational man hours and significantly increased the amount of time required to progress the investigation. The issues faced by the police in this instance inspired a technical solution to significantly reduce the time, man power resources, (and costs) needed to review large amounts of CCTV recordings while searching for key points of evidence.

Find - Forensic investigation Network Database – has been developed with the capability of linking to any CCTV recording system to create and index key objects of interest at the time of video capture and storage. The technology works by allowing operators to search via a powerful 'Find' processing engine that immediately identifies relevant footage. By inputting key parameters, the system will search the database of classified objects and display relevant images using thumbnail identification, ready for review. The speed of response is derived from searching the object data index, rather than the traditional video based ‘region of interest’ search, using selected areas of a specific camera”.

FiND emerged from initial research undertaken by Loughborough University evaluating the most technically challenging aspects of using automated video analysis to search large volumes of existing CCTV recordings for key or ‘known’ objects of interest. Performing complex video analysis on recordings from public space cameras in particular is challenging and the development team had to overcome many limitations affecting image quality. Two areas in particular quickly became evident as barriers to progress: colour consistency and lighting/shadowing. The team developed algorithms to overcome these barriers and this dramatically improved the video consistency and the accuracy of results.

Generating colour and lighting consistency formed the foundation for the research and development of a comprehensive set of algorithms specifically aimed at resolving vehicle classification, people classification, license plate identification using CCTV cameras, text/logo detection, baggage detection, complex background processing and PTZ compensation. A number these algorithms are completely unique.

Find functions by the creation of a database of key objects of information extracted from the video as it is being recorded. This information is normally referred to as metadata and provides the source of results for all future searches. The stored metadata is negligible in size when compared to standard resolution and frame rate video. Thus storing all key objects of interest from an entire system in this way become irrelevant in overall storage terms. The metadata is created in real time by processing the recorded video using the unique algorithms. This process captures all relevant objects within each video scene to give operators a wide range of search criteria for any future investigation.

As an example of the scope of search the criteria can be set to ‘person wearing red shirt’. Further refinement can be added to achieve ‘person wearing red shirt, carrying a back pack at a specific time of day’. Searching in this way then occurs across the entire source of metadata from all cameras. This produces the most comprehensive set of results from entire recording systems using a single step process.

According to Craig Howie, “Find will reduce the search period of days, weeks - or months - worth of digitally recorded video down to a matter of seconds."