Both of today's issued patents concern the use of watermarking. Assigned to the University of Rochester (NY), the first describes techniques for data hiding via phase manipulation of audio signals. Assigned to Inventec Appliances (Taiwan), the second describes ways of protecting the copyright of digital video works in part by using watermarks.
7,289,961, "Data hiding via phase manipulation of audio signals", assigned to the University of Rochester (NY).
Data are embedded in an audio signal for watermarking, steganography, or other purposes. The audio signal is divided into time frames. In each time frame, the relative phases of one or more frequency bands are shifted to represent the data to be embedded. In one embodiment, two frequency bands are selected according to a pseudo-random sequence, and their relative phase is shifted. In another embodiment, the phases of one or more overtones relative to the fundamental tone are quantized.
7,286,668, "Method of protecting copyright of digital video work," assigned to Inventec Appliances Corp. (Taipei Hsien, TW)
This invention discloses a method of protecting copyright of a digital video work by using a digital password technology and a digital watermark technology to prevent the unauthorized use of a digital video work. Such method adds password protection of two chrominance arrays of such video work in advance, so that when such video work is published on the Internet, it can only be played in color by a specified player. As long as a user enters the correct password into the specified player, a full color visual effect of such video work can be obtained. If other players are used to play such video work, only a partial gray-scale visual effect can be obtained. Users must request or buy a specific player and a password from the distributor of such video work to play the complete information to prevent piracy.