Both of todays issued patents deal with watermarking. Assigned to Digimarc, the first addresses measuring quality of service of broadcast multimedia signals using watermark analyses. Assigned to Matsushita, the second patent concerns a digital watermark system.
7,277,468, "Measuring quality of service of broadcast multimedia signals using digital watermark analyses," assigned to Digimarc.
Abstract
The disclosure details a method of measuring the quality of service of broadcast media signals by analyzing digital watermarks embedded in the received broadcast signal. This method enables the quality of the broadcast video or audio signal to be measured without having the original version of the signal before broadcast transmission. Instead, the method analyzes the strength or quality of the embedded digital watermark to determine the quality of the received broadcast signal. The degradation of a watermark signal is used to measure quality of service of broadcast signals, such as audio and video.
7,277,871, "Digital watermark system," assigned to Matsushita Electric Industrial Co. (JP).
Abstract
A digital watermark embedding apparatus generates an echo signal, which is delayed a time period corresponding to digital watermark information to be embedded with respect to each tone signal that forms an original audio signal, and inserts the generated echo signal in the original audio signal by spreading the echo signal on the time axis, thus outputting a watermarked audio signal. A digital watermark detection apparatus despreads echo signals contained in the watermarked audio signal on the time axis, and extracts digital watermark information from the generation time of the despread echo signal contained in the watermarked audio signal.
