Transform domain image watermarking method and system
First Claim
1. A method of robust digital image watermarking for embedding a predetermined bit sequence into a digital image, said digital image comprising spatial domain data signals, said method including the steps of:
- transforming said digital image into frequency domain data signals including respective magnitude and phase data signal components;
determining a set of contiguous regions in the frequency domain; and
embedding said predetermined bit sequence directly into said image frequency domain data signals by mapping bits to well-defined regions in the frequency domain.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and system for watermarking and recovering a watermarked digitized image for subsequent authentication. The digitized image comprises spatial domain data signals reproduced from an original image. A transformer transforms the spatial domain data signals into frequency domain data signals, including respective magnitude and phase data signal components. Information is embedded into the magnitude data signals to develop modified data signals and the modified data signals are converted from the frequency domain to the spatial domain to generate the watermarked digitized image. For recovery, a second transformer transforms the spatial domain data signals comprising the respective original digitized image and watermarked digitized image into respective frequency domain dataset signals. A comparator responsive to the two transformer outputs compares the respective frequency domain dataset signals to identify the watermark and verify the authenticity of the image reproduction.
43 Citations
25 Claims
-
1. A method of robust digital image watermarking for embedding a predetermined bit sequence into a digital image, said digital image comprising spatial domain data signals, said method including the steps of:
-
transforming said digital image into frequency domain data signals including respective magnitude and phase data signal components;
determining a set of contiguous regions in the frequency domain; and
embedding said predetermined bit sequence directly into said image frequency domain data signals by mapping bits to well-defined regions in the frequency domain. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of watermarking a digitized image for subsequent authentication, said digitized image comprising spatial domain data signals and being reproduced from an original image, said method including the steps of:
-
transforming said spatial domain data signals into frequency domain data signals including respective magnitude and phase data signal components;
embedding information signals into said magnitude data signals to develop modified data signals; and
converting said modified data signals from said frequency domain to said spatial domain to generate said watermarked digitized image. - View Dependent Claims (9, 10, 11, 12, 13, 15, 16, 18, 19, 20, 21, 22, 23)
-
-
14. A watermarking apparatus for tagging a digitized image for subsequent authentication, said digitized image comprising spatial domain data signals and being reproduced from an original image, said apparatus including:
-
a transformer, said transformer operating to transform said spatial domain data signals into frequency domain data signals, including respective magnitude and phase data signal components;
a processor disposed to receive the output of said transformer, said processor being operative to embed information signals into said magnitude data signals to develop modified data signals; and
a converter located to receive the output of said processor, said converter operative to convert said modified data signals from said frequency domain to said spatial domain to generate said watermarked digitized image.
-
-
17. A method of recovering a watermark from a tagged digitized image comprising a reproduction of an original digitized image, said tagged digitized image and said original digitized image both comprising spatial domain dataset signals, said method including the steps of:
-
transforming said spatial domain data set signals comprising said respective original and tagged image signals into respective frequency domain dataset signals; and
comparing said respective frequency domain dataset signals to identify said watermark and verify the authenticity of said image reproduction.
-
-
24. A watermark recovery apparatus for authenticating a tagged digitized image comprising a reproduction of an original image, said respective images comprising spatial domain dataset signals, said apparatus including:
-
a transformer, said transformer operative to transform said spatial domain data signals comprising said respective images into respective frequency domain dataset signals; and
a comparator, said comparator being responsive to said transformer to compare said respective frequency domain dataset signals to identify said watermark and verify the authenticity of said image reproduction.
-
-
25. A digitized image authentication system for implanting and detecting watermark information in a digitized reproduction of an image, said digitized image comprising spatial domain data signals and being reproduced from an original image, said system including:
-
a watermarking apparatus for tagging said digitized image signals, said apparatus including a transformer located to receive said spatial domain data signals, said transformer operative to transform said spatial domain data signals into frequency domain data signals including respective magnitude and phase data signal components;
a processor disposed at the output of said transformer, said processor being operative to embed information into said magnitude data signals to develop modified data signals;
a converter positioned to receive the output of said processor, said converter being operative to convert said modified data signals from said frequency domain to said spatial domain to generate said watermarked digitized image signals; and
a watermark recovery apparatus for authenticating said tagged digitized image, said recovery apparatus including;
a transformer located to receive said spatial domain data signals comprising said respective images, said transformer being operative to transform said spatial domain data signals into respective frequency domain dataset signals; and
a comparator receiving said respective frequency dataset signals from said transformer, said comparator being operative to compare said respective frequency domain dataset signals to identify said watermark and verify the authenticity of said image reproduction.
-
Specification