Multiple watermarks in content
View Patent ↗Image, video, and/or audio data is encoded with at least first and second watermarks. In one implementation a method includes: receiving content; embedding a first watermark signal in the content; compressing the content; embedding a second watermark signal in the content. The first watermark signal and the second watermark signal are designed to respond differently to at least a first type of signal processing. Other implementations are also provided.
1. A method comprising:
receiving content comprising at least video and audio;
analyzing the content to determine whether a first watermark signal and a second watermark signal are encoded in content;
when the first watermark signal is present in the content, but not the second watermark signal, making a first decision concerning the content; and
when both the first watermark signal and the second watermark signal are present in the content, reaching a second, different, decision concerning the content.
2. The method of claim 1 , wherein the first and second watermark signals are encoded in the content with digital watermarking.
3. The method of claim 2 , in which the first watermark signal is designed to withstand a predetermined process, and the second watermark signal is not.
4. A machine-readable medium comprising instructions stored therein, wherein the instructions comprise instructions to perform the method of claim 1 .
5. A method comprising:
receiving content;
embedding a first watermark signal in the content;
compressing the content;
embedding a second watermark signal in the content,
wherein the first watermark signal and the second watermark signal are designed to respond differently to at least a first type of signal processing.
6. The method of claim 5 , wherein the first watermark signal comprises first information and the second watermark signal comprises second information.
7. The method of claim 5 , wherein the first watermark information is designed to withstand a first type of signal processing, and the second watermark information is not.
8. The method of claim 5 wherein the first type of signal processing comprises at least decompression.
9. A printed document including a first substrate with ink or dye provided thereon, the ink or dye forming at least:
a first watermark; and
a second watermark,
wherein the first watermark corresponds with a first characteristic and the second watermark corresponds with a second characteristic, and
wherein the first and second characteristics are affected in a different manner when the document is subjected to a first type of processing.
10. The printed document of claim 9 wherein the first corruption process comprises a color transformation.
11. The document of claim 10 wherein the first characteristic comprises a first color.
12. The document of claim 11 wherein the second characteristic comprises a second color.