Low visible digital watermarks

• US 7,738,673 B2
• Filed: 06/14/2005
• Issued: 06/15/2010
• Est. Priority Date: 04/19/2000
• Status: Expired due to Term

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Reed, Alastair M.
• Primary Examiner(s): Mehta; Bhavesh M
• Assistant Examiner(s): Rosario; Dennis
• Application Number:
  US11/153,901
• Publication Number:
  US 20060008112A1
• Time in Patent Office: 1,827 Days
• Field of Search: 382/100
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/0042 Fragile watermarking, e.g. so as to detect tampering
• CPC Class Codes: G06T 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: H04N 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• CPC Class Codes: H04N 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32229 with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32251 in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32288 Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
• CPC Class Codes: H04N 1/32293 Repeating the additional information in a regular pattern
• CPC Class Codes: H04N 1/32309 in colour image data
• CPC Class Codes: H04N 2201/327 which are undetectable to the naked eye, e.g. embedded codes

Abstract

The present invention relates to digital watermarking. In a preferred embodiment, media is embedded with one or more digital watermark components. The media includes a blue color plane, a red color plane and a green color plane. The digital watermark component is embedded in the blue color plane, and scaled versions of the digital watermark component are embedded in the red and green color planes. The scaling of component in the red and green color planes helps insure that luminance attributable to the blue color digital watermark component is reduced or offset. A related watermark detection scheme is disclosed.

Claims

1. A method to embed a first digital watermark in media, wherein said media includes a blue color channel, a red color channel and a green color channel, said method comprising:

utilizing a multi-purpose processor configured to;

provide a signal change in terms of a color value, wherein the signal change corresponds to one or more digital watermark components to be applied to an area of the media;

first change one or more color values in the area in the blue color channel according to the signal change; and

second change one or more color values in the area in the red color channel and the green channel to reduce luminance attributable to the signal change in the blue channel.

2. The method of claim 1 further comprising printing the media after said first changing and second changing, wherein a resulting printed media comprises the first digital watermark embedded therein.

3. The method of claim 2 wherein prior to said printing, the blue color channel, red color channel and green color channel are convened to at least yellow, magenta and cyan channels.

4. The method of claim 2 wherein said first digital watermark is detectable from analyzing at least chrominance characteristics associated with the printed media.

5. The method of claim 1 further comprising embedding a second digital watermark in the media, wherein said first digital watermark and said second digital watermark are separately detectable in a printed version of the media.

6. The method of claim 5 wherein the second digital watermark is detectable from analyzing luminance characteristics associated with the printed version of the media.

7. A computer readable medium comprising instructions stored thereon to cause a multi-purpose computer processor to perform the acts of claim 1.

8. A programmed computing device storing instructions in memory, said instructions are executable by said programmed computing device to perform the acts of claim 1.

9. A method to embed a first digital watermark in media, wherein said media includes a blue color channel, a red color channel and a green color channel, said method comprising:

utilizing a multi-purpose processor configured to;

provide a signal change in terms of a color value, wherein the signal change corresponds to one or more watermark components to be applied to an area of the media;

first change one or more color values in the area in the blue color channel according to the signal change; and

second change one or more color values in the area in the red color channel and the green channel to reduce luminance attributable to the signal change in the blue channel, changing one or more color values in the area in the red color channel and the green channel changes color values in each of the red and green channel by ⅛

of an amount of the signal change in the blue channel.

10. A computer readable medium comprising instructions stored thereon to cause a multi-purpose computer processor to perform the acts of claim 9.

11. A programmed computing device storing instructions in memory, said instructions are executable by said programmed computing device to perform the acts of claim 9.

12. An apparatus comprising:

electronic memory for buffering a media signal, the media signal includes a blue color channel, a red color channel and a green color channel; and

a multi-purpose computer processor configured to;

provide a signal change in terms of a color value, wherein the signal change corresponds to one or more watermark components to be applied to an area of a media signal;

first change one or more color values in the area in the blue color channel according to the signal change; and

second change one or more color values in the area in the red color channel and the green channel to reduce luminance attributable to the signal change in the blue channel.

13. The apparatus of claim 12 in which the multi-purpose computer processor is executing to perform at least one of the functions recited in claim 12.