Measuring quality of service of broadcast multimedia signals using digital watermark analyses

• US 20020076084A1
• Filed: 09/10/2001
• Published: 06/20/2002
• Est. Priority Date: 09/11/2000
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Levy, Kenneth L., Tian, Jun, Brunk, Hugh L.
• Granted Patent: US 7,277,468 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0042 Fragile watermarking, e.g. so as to detect tampering
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/3216 using Fourier transforms
• CPC Class Codes: H04N 17/004 for digital television systems
• CPC Class Codes: H04N 21/4425 Monitoring of client processing errors or hardware failure
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467

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.

Claims

1. A method of measuring quality of service of a broadcast media signal using a digital watermark embedded in the broadcast media signal, the method comprising:

extracting a digital watermark from the broadcast media signal; and

evaluating the extracted digital watermark relative to a reference digital watermark to measure degradation in quality of service of the broadcast media signal based on differences between the extracted and reference digital watermarks.

2. A computer readable medium on which is stored instructions for performing the method of claim 1.

3. The method of claim 1 wherein the evaluating includes comparing signal peaks of the broadcast media signal and the reference digital watermark.

4. The method of claim 3 wherein the signal peaks comprise frequency domain peaks.

5. The method of claim 3 wherein the evaluating includes measuring signal strength of the extracted watermark by measuring differences between a watermark message signal decoded from the broadcast media signal and a reference watermark message signal.

6. The method of claim 5 wherein the watermark message signal decoded from the broadcast media signal is spread spectrum demodulated from the broadcast media signal.