System and method of watermarking a signal
First Claim
Patent Images
1. A system for generating a watermarked signal, the system comprising:
- (1) a processor;
(2) a module configured to control the processor to segment a signal into overlapping blocks using a window function;
(3) a module configured to control the processor to window each odd-numbered block using the window function; and
(4) a module configured, for even-numbered blocks to control the processor to;
(a) transform each block into a frequency domain;
(b) modulate a phase of each block in the frequency domain by constraining the phase change inside a critical band to prevent an audible envelope change in a time signal;
(c) transform each modulated block in a time domain;
(d) window each block transformed into the time domain; and
(5) a module configured to control the processor to generate a watermarked signal by overlap-adding each odd-numbered block with each even-numbered block.
0 Assignments
0 Petitions
Accused Products
Abstract
A system and method of generating a watermarked signal are disclosed. The system segments the signal into overlapping blocks using a window function and processes the overlapping blocks according to whether each block is odd- or even-numbered. The system windows the odd-numbered blocks, modulates the phase of each block in the frequency domain, transforms each modulated block in the time domain, windows each block transformed into the time domain and overlap-adds each odd-numbered block with each even-numbered block to generate the watermarked signal.
27 Citations
29 Claims
-
1. A system for generating a watermarked signal, the system comprising:
-
(1) a processor; (2) a module configured to control the processor to segment a signal into overlapping blocks using a window function; (3) a module configured to control the processor to window each odd-numbered block using the window function; and (4) a module configured, for even-numbered blocks to control the processor to; (a) transform each block into a frequency domain; (b) modulate a phase of each block in the frequency domain by constraining the phase change inside a critical band to prevent an audible envelope change in a time signal; (c) transform each modulated block in a time domain; (d) window each block transformed into the time domain; and (5) a module configured to control the processor to generate a watermarked signal by overlap-adding each odd-numbered block with each even-numbered block. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A system that adds message bits to a signal, the system comprising:
-
(1) a processor; (2) a module configured to control the processor to segment a signal into overlapping blocks using a window function; (3) a module configured, for odd-numbered blocks, to control the processor to; (a) window each block using the window function; and (4) a module configured, for even-numbered blocks, to control the processor to; (a) in a frequency domain, embed a message bit into every integer bark-scale bin for each block, wherein a phase modulation for a k-th block is;
Φ
k(b)=Σ
aio(b−
i), 0.0≦
b≦
I, for i=1 to I, where I is the maximum bark scale for embedding watermark;(b) overlap and add adjacent window functions wherein the phase modulation for an i-th bark-scale bin is;
Φ
k(b)=ai-1Ø
(b−
(i−
1))+aiØ
(b−
i), for i−
1≦
b<
i;(c) modulate a phase of each block on a bark scale, wherein each integer bark scale bin carries a message bit; (d) transform each modulated block in a time domain; (e) window each block transformed into the time domain; and (5) a module configured to control the processor to generate a watermarked signal by overlap-adding each odd-numbered block with each even-numbered block. - View Dependent Claims (8, 9)
-
-
10. A system for generating a watermarked signal from a signal, the system comprising:
-
(1) a processor; (2) a module configured to control the processor to segment the signal into overlapping blocks sk(n), n=O, . . . , N−
1 using a window function;(3) a module configured, for odd-numbered blocks, to control the processor to; (a) window each block using the window function to generate blocks s*k(n); and (4) a module configured, for even-numbered blocks, to control the processor to; (a) in a frequency domain, embed a message bit into every integer bark-scale bin for each even-numbered block Sk(f), wherein a phase modulation for a k-th block is; Φ
k(b)=Σ
aie(b−
i), 0.0≦
b≦
I, where b=13 arctan (0.76f/1000)+3.5 arctan(f/7500)2) and where the resulting signal for each even-numbered block is;S k(f)=Sk(f)·
ejΦ
k(f), f=0, . . . , N−
1,(b) in a time domain, window the phase modulated block to generate s ·
s(n); and(5) a module configured to control the processor to generate a watermarked signal by overlapping and adding s *k(n) and s*k(n). - View Dependent Claims (11, 12)
-
-
13. A system for generating a watermarked signal from a signal, the system comprising:
-
(1) a processor; (2) a module configured to control the processor to window the signal into overlapping windowed blocks sk(n), n=0, . . . , N−
1 using a window function;(3) a module configured to control the processor to window each odd block to generate s*k(n), n=0, . . . , N−
1, k=1, 3 . . . odd numbers;(4) a module configured, for each even block sk(n), n=0, . . . , N−
1, k=0, 2 . . . even numbers, to control the processor to;(a) transform sk(n) into a frequency domain as Sk(f); (b) phase modulate Sk(f) in the frequency domain to generate S k(f) and apply a message bit to the integer bark scale associated with each block Sk(f), wherein the phase modulation for a k-th block is;Φ
k(b)=Σ
aiØ
(b−
i), 0.0≦
b≦
I, where I is a maximum bark scale for embedding the watermark;(c) transform Sk(f) into a time domain to generate s k(n);(d) window s k(n) in the time domain to generates *k(n); and(5) a module configured to control the processor to form a watermarked signal by overlap-adding the odd and even blocks to form the watermarked signal. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
-
-
21. A system for generating a watermarked signal from a signal, the system comprising:
-
(1) a processor; (2) a module configured to control the processor to segment the signal into overlapping blocks using a window function; (3) a module configured, for odd-numbered blocks, to control the processor to; (a) window each block using the window function to generate odd-numbered windowed blocks; and (4) a module configured, for even-numbered blocks, to control the processor to; (a) in a frequency domain, embed a message bit into every integer bark-scale bin for each even-numbered block, wherein the phase modulation for a k-th block is Φ
k(b)=Σ
aiØ
(b−
i) and |(dØ
/db)|<
30°
, where Ø
is the signal phase, and b is the bark scale; and(b) in a time domain, window the phase-modulated block; and (5) a module configured to control the processor to generate a watermarked signal by overlapping and adding the odd-numbered windowed blocks and even-numbered phase-modulated blocks. - View Dependent Claims (22, 23, 24)
-
-
25. A system for generating a watermarked signal from a signal that is segmented into overlapping blocks using a window function and where odd-numbered blocks are windowed using the window function, the system comprising, for even-numbered blocks:
-
(a) a processor; (b) a module configured to control the processor to determine whether an audibility rule is met; and (c) a module configured, if the audibility rule is met, to control the processor to embed a message bit into every integer bark-scale bin for each even-numbered block, wherein if the audibility rule is met, the phase modulation for the k-th even-numbered block is Φ
k(b)=Σ
aiØ
(b−
i), where Ø
is the signal phase, and b is the bark scale, wherein a watermarked signal is generated using the even-numbered blocks and the odd-numbered blocks. - View Dependent Claims (26, 27)
-
-
28. A system for generating a watermarked signal from a signal that is segmented into overlapping blocks using a window function, the system associated with using the segmented blocks to perform phase modulation of even-numbered blocks and overlap-adding the even-numbered blocks and odd-numbered blocks to generate the watermarked signal, the system comprising:
-
(a) a processor; (b) a module configured to control the processor to determine whether an audibility rule is met; and (c) a module configured, if the audibility rule is met, to control the processor to embed a message bit into every integer bark-scale bin for each even-numbered block, wherein if the audibility rule is met, the phase modulation for the k-th even-numbered block is Φ
k(b)=Σ
aiØ
(b−
i), where Ø
is the signal phase, and b is the bark scale, wherein a watermarked signal is generated based on the even-numbered blocks and odd-numbered blocks. - View Dependent Claims (29)
-
Specification