Video pirates are under threat as researchers at a Japanese university develop an audio based weapon, designed to keep illegally recorded copies off the streets. The Osaka University team, led by Noboru Babaguchi, say they can build ‘Digital watermarks’ into a film that can detect the seat someone was sitting in when they made an illegal copy of a production.
When the soundtrack is mixed the waveform of music and speech is slightly varied at regular intervals. If an illegal recording is seized the seat the culprit was sitting in can be pinpointed by using the “audio watermark†to determine how far away the microphone was from each of the loudspeakers. However, authorities would have to know which cinema that recording was taken from and it is not clear how they would use the information to actually apprehend a pirate.
If the technology can be effectively utilised to apprehend criminals it will be welcomed by the film industry which looses billions of dollars a year to video piracy.
The new application of digital watermarking is explained in a paper that will be published in 'IEEE Transactions on Multimedia' a telecommunications journal.