Methods for marking images
First Claim
Patent Images
1. A method for imparting a watermark onto a digitized image comprising the steps of:
- providing said digitized image comprised of a plurality of pixels, wherein each of said pixels includes brightness data that represents a brightness of at least one color; and
multiplying said brightness data associated with at least one of said pixels by a predetermined brightness multiplying factor, said brightness multiplying factor, “
mf”
, is selected from the group consisting of (0.9<
=“
mf”
<
1), and (1<
“
mf”
<
=1.1).
1 Assignment
0 Petitions
Accused Products
Abstract
An image is marked by making slight changes to pixel values. These changes are essentially imperceptible on human scrutiny, but detectable by computer analysis. Such markings have applications in identifying ownership of images (including video), and also in device control (e.g., triggering a “do not copy” response in suitably configured hardware and software systems).
105 Citations
20 Claims
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1. A method for imparting a watermark onto a digitized image comprising the steps of:
-
providing said digitized image comprised of a plurality of pixels, wherein each of said pixels includes brightness data that represents a brightness of at least one color; and
multiplying said brightness data associated with at least one of said pixels by a predetermined brightness multiplying factor, said brightness multiplying factor, “
mf”
, is selected from the group consisting of (0.9<
=“
mf”
<
1), and (1<
“
mf”
<
=1.1). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18)
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13. A method for generating a watermarked image wherein a watermark is imparted onto a digitized image having a plurality of original elements having original brightnesses, said method comprising the steps of:
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providing a digitized watermarking plane comprising a plurality of watermarking elements, each having a watermark brightness multiplying factor and having one-to-one correspondence with said original elements; and
producing a watermarked image by multiplying said original brightness of each of said original elements by said brightness multiplying factor of a corresponding one of said watermark elements wherein said watermark is invisible.
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19. A method for imparting a watermark onto a digitized image comprising the steps of:
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providing said digitized image comprised of a plurality of pixels, wherein each of said pixels includes brightness data that represents a brightness of at least one color; and
multiplying said brightness data associated with at least one of said pixels by a predetermined brightness multiplying factor in the range of 0.9 to 1.1, wherein said brightness multiplying factor has a relationship with a number taken from a random number sequence, said relationship is a linear remapping to provide a desired modulation strength, and said modulation strength is less than 0.5 percent.
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20. A method for imparting a watermark onto a digitized image comprising the steps of:
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providing said digitized image comprised of a plurality of pixels, wherein each of said pixels includes brightness data that represents a brightness of at least one color; and
multiplying said brightness data associated with at least one of said pixels by a predetermined brightness multiplying factor in the range of 0.9 to 1.1, wherein said brightness multiplying factor has a relationship with a number taken from a random number sequence, said relationship is a linear remapping to provide a desired modulation strength, said sequence is formed from a plurality of robust watermarking parameters, and said parameters comprise a cryptographic key, two coefficients and an initial value of said random number generator.
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Specification