Philips Electronics is launching a service to help Web sites and online file-sharing networks filter out unauthorized copyrighted video files. The service, dubbed MediaHedge, is the latest anti-piracy tool designed to help sift through the growing volume of online video files and give copyright holders more say over their content.

YouTube and others are developing technology that will streamline the process by which copyright owners identify content for removal.

Philips did not name any customers who will be using the MediaHedge system, which works by checking the digital “fingerprint” or unique characteristics of video files and looking for a match in Philips’ database of video content.

The service can spot a match even if the video file is degraded, altered or amounts to a small slice of the original video, according to Philips Content Identification, a unit of the Netherlands’ Philips Electronics.

Copyright holders can specify in advance whether they want to allow videos containing their footage to be posted on sites running MediaHedge, or whether they should be blocked or otherwise restricted.