WATERMARK EMBEDDING FUNCTIONS ADAPTED FOR TRANSMISSION CHANNELS

• US 20070177761A1
• Filed: 11/28/2006
• Published: 08/02/2007
• Est. Priority Date: 03/18/2000
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Levy, Kenneth
• Granted Patent: US 8,045,748 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06F 21/1063 Personalisation

Abstract

A method for controlling watermark embedding in a media object through the use of a watermark embedding command. The use of the embedding command enables watermark embedding to be adapted for the transmission channel at the time of transmission.

Claims

1. A method for controlling embedding of a digital watermark in a media signal, comprising:

receiving a watermark embedding function specifying watermark embedding parameters, including watermark message payload;

storing the watermark embedding function in association with the media signal; and

at transmission of the media signal into a transmission channel, reading the watermark embedding function and steganographically embedding the watermark message payload into the media signal by making adjustments to the media signal to adapt the digital watermark to the transmission channel.

2. The method of claim 1 wherein the media signal comprises graphic art including a collection of two or more images in different formats.

3. The method of claim 1 wherein the media signal comprises a music signal, and the steganographic embedding process is adapted to the robustness or perceptual quality parameters related to the transmission channel.

4. The method of claim 1 wherein the media signal comprises a music signal, and the steganographic embedding process is adapted to the robustness or perceptual quality parameters related to the transmission channel.

5. The method of claim 1 wherein the steganographic embedding process includes:

iteratively embedding the message payload in two or more iterations;

analyzing the error detection rate of the message payload in each iteration; and

adjusting a robustness parameter of the embedding process for at least one of the iterations so that the error detection rate is at an acceptable level.

6. The method of claim 1 including:

providing two or more different watermark embedding modules, each adapted for different transmission channels, the watermark embedding modules being selected depending on the transmission channel to which the media object is to be applied.

7. The method of claim 1 wherein the watermark embedding function specifies the embedding locations of the watermark.

8. The method of claim 1 wherein, at transmission, the steganographic embedding process selects the embedding locations of the watermark depending on the transmission channel.

9. The method of claim 1 wherein the media signal comprises an image, and the steganographic embedding process embeds the watermark message payload into the image after the image is rasterized into a format compatible with a printer on which the image is to be printed.

10. The method of claim 1 wherein the watermark message payload is embedded in the image after it is converted into a halftone image by a halftoning process compatible with the printer on which the image is to be printed.

11. A media object processing system comprising:

input means for enabling a user to specify commands for a media object, including a watermark embedding function to be applied to the media object, the watermark embedding function including parameters controlling embedding of a watermark message payload in the media object;

and a watermark embedder module for steganographically embedding the watermark message payload into the media object based on the watermark embedding function and a transmission channel;

the watermark embedder module varying adjustments of the media object with the transmission channel to embed the watermark message payload in the media object dependent on the transmission channel.

12. The system of claim 11 where in the system is operable to select different embedding modules for different transmission channels.

13. The system of claim 11 wherein the embedder module is operable to iteratively embed the watermark message payload in the media object in two or more iterations, and with each iteration, analyzing an error detection rate of the message payload to adapt robustness of the watermark.

14. The system of claim 13 wherein the watermark embedder module applies a degradation process to a watermarked media signal output from an iteration before analyzing the error detection rate.

15. A computer readable medium comprising:

one or more commands describing how to embed a digital watermark in a media object; and

a watermark embedding function specifying how to embed a watermark message payload into the media object, wherein adjustments made to embed the watermark message payload vary with the transmission channel.