Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
79 words
A method of decoding steganographic messages embedded within digital signals comprising the following steps: filtering the digital signal with a restoration filter to produce a restored digital signal; subtracting the restored digital signal from the digital signal to produce a difference signal; deinterleaving the difference signal; replicating a pseudorandom spreading sequence; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code to produce a decoded message.
Claim 2
Independent Claim
79 words
A method of decoding steganographic messages embedded within digital signals comprising the following steps: filtering the digital signal with a restoration filter to produce a restored digital signal; subtracting the restored digital signal from the digital signal to produce a difference signal; deinterleaving the difference signal; replicating a pseudorandom spreading sequence; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code to produce a decoded message.
Claim 3
Dependent Claim
15 words
The method of claim 1 , further comprising: decrypting the decoded message with a key.
Claim 4
Independent Claim
95 words
A method of decoding steganographic messages embedded within digital images comprising the following steps: filtering the digital image with a restoration filter to produce a restored digital image; subtracting the restored digital image from the digital image to produce a difference signal; deinterleaving the difference signal according to a key; replicating a pseudorandom spreading sequence according to a key; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce a decoded message.
Claim 5
Independent Claim
95 words
A method of decoding steganographic messages embedded within digital images comprising the following steps: filtering the digital image with a restoration filter to produce a restored digital image; subtracting the restored digital image from the digital image to produce a difference signal; deinterleaving the difference signal according to a key; replicating a pseudorandom spreading sequence according to a key; demodulating the deinterleaved signal with the spreading sequence to construct an estimate of the message; decoding the message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce a decoded message.
Claim 6
Independent Claim
79 words
A method of steganography for concealing messages within digital signals comprising the steps of: encoding an input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; and combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded.
Claim 7
Independent Claim
79 words
A method of steganography for concealing messages within digital signals comprising the steps of: encoding an input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; and combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded.
Claim 8
Dependent Claim
15 words
The method of claim 4 , further comprising encrypting the input message with a key.
Claim 9
Dependent Claim
19 words
The method of claim 4 , further comprising interleaving the embedded signal to enhance recovery of the embedded signal.
Claim 10
Dependent Claim
20 words
The method of claim 6 , where the step of interleaving the embedded signal is performed according to a key.
Claim 11
Dependent Claim
14 words
The method of claim 4 , where the cover signal is a digital image.
Claim 12
Dependent Claim
19 words
The method of claim 4 , where the error correcting code comprises a binary expansion of a Reed-Solomon code.
Claim 13
Dependent Claim
15 words
The method of claim 4 , wherein the piecewise linear function comprises a sign function.
Claim 14
Dependent Claim
77 words
The method of claim 4 , wherein the generation of the spreading sequence and piecewise linear modulation comprises: generating a uniformly distributed random sequence, u; generating a second sequence u′ according to the following formula u ′ = { u + 0.5 , 0 ≤ u ≤ 0.5 u - 0.5 , 0 ≤ u ≤ 0.5 ; forming a spreading sequence by a switch arbitrator which selects from u and u′ arbitrated by the input message.
Claim 15
Independent Claim
119 words
A method of steganography for concealing messages within digital signals comprising the following steps: encrypting an input message with a key and encoding the input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encodeded message by the spreading sequence to produce an embedded signal and interleaving the embedded signal to enhance recovery of the embedded signal, where the interleaving step is performed according to a key; combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded; and quantizing the stegosignal to preserve the original the original dynamic range of the cover signal.
Claim 16
Independent Claim
119 words
A method of steganography for concealing messages within digital signals comprising the following steps: encrypting an input message with a key and encoding the input message with an error correcting code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encodeded message by the spreading sequence to produce an embedded signal and interleaving the embedded signal to enhance recovery of the embedded signal, where the interleaving step is performed according to a key; combining the embedded signal with a cover signal to produce a stegosignal in which the input message is embedded; and quantizing the stegosignal to preserve the original the original dynamic range of the cover signal.
Claim 17
Independent Claim
123 words
A method of steganography for concealing messages within digital images comprising the following steps: encrypting an input message with a key; encoding the input message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; interleaving the spread spectrum modulated signal according to a key; combining the embedded signal with a cover image to produce spread spectrum modulated stegoimage in which the input message is embedded; and quantizing the interleaved spread spectrum modulated stegoimage to preserve the original dynamic range of the cover image.
Claim 18
Independent Claim
123 words
A method of steganography for concealing messages within digital images comprising the following steps: encrypting an input message with a key; encoding the input message with an error correcting code comprising a binary expansion of a Reed-Solomon code to produce an encoded message; generating a spreading sequence with a pseudorandom noise generator according to a key; modulating the encoded message by the spreading sequence using a piecewise linear technique to produce an embedded signal; interleaving the spread spectrum modulated signal according to a key; combining the embedded signal with a cover image to produce spread spectrum modulated stegoimage in which the input message is embedded; and quantizing the interleaved spread spectrum modulated stegoimage to preserve the original dynamic range of the cover image.
Claim 19
Dependent Claim
14 words
The method of claim 13 wherein the piecewise linear function comprises a sign function.
Claim 20
Dependent Claim
70 words
The method of claim 13 wherein generation of the spreading sequence comprises generating a uniformly distributed random sequence, u; generating a second sequence u′ according to the following formula u ′ = { u + 0.5 , 0 ≤ u ≤ 0.5 u - 0.5 , 0 ≤ u ≤ 0.5 forming a spreading sequence by a switch arbitrator which selects from u and u′ arbitrated by the input message.