PRESENTED BY,

C.RESHMA –II CSE

S.POORNIMA –II IT

watermarking is to protect one’s work from being hijacked.It also deals with various types of Watermark attacks. When unauthorized copies or forgeries of the image appear elsewhere on the network, the designer needs to prove his ownership of the image.

Imperceptible: The watermark should be imperceptible so as not to affect the viewing experience of the image or the quality of the audio signal. Undetectable: The watermark must be difficult or even impossible to remove by a malicious cracker, at least without obviously degrading the host signal.

Statistically undetectable: A pirate should not be able to detect the watermark by comparing several watermarked signals belonging to the same authorUnambiguous: Retrieval of the watermark should unambiguously identify the owner, and the accuracy of identification should degrade gradually in the face of attacks.

VisibleFragileSpatialImage –adaptiveBlindPublic & privateAsymmetric&symmetri watermarkingSteganographic&non-stenographicImage watermarking

Watermarking can be applied in the frequency domain by first applying a transform like the Fast Fourier Transform (FFT), Discrete Cosine Transform (DCT), Wavelet Transform etc.hi gh frequencies will be lost by compression or scaling, the watermark signal is applied to lower frequenciesfrequencies that contain important information of the original picture

Frequency methods encode the data across the global frequencies of the image.

Two types of information hiding methods areFast Fourier Transform (FFT)Discrete Cosine Transform (DCT)

FFT ISOLAT

FFT

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This transformation is one that converts the time domain signal into a signal of frequency domain

IFFT

OUTPUT

WATERMARK

Start the process.Get the text data to a binary row vector.Convert the text data to a binary row vector.Scale the binary vector.Create the data mark.Compute the FFT and decompose into the magnitude and phase.Create the ring of the data mark (using loops).Add the ring to the magnitude of the image.

Reduce the magnitude points where the data bit is zero. Convert the matrix into an image (i.e. watermarked image). Output the watermarked image. Stop the process.

APPLICATION: Audio watermarking Text watermarking Fingerprinting

Common attack techniques: Additive noise Cropping Rotation & Scaling

Digital watermarking is an effective technique for protecting intellectual property (IP) It bears a huge commercial potential, used in consumer electronic devices. Digital watermark technology can be used in consumer electronic devices such as digital still cameras, digital video cameras, set top boxes, DVD players, and MP3 players. As a result it can protect information in controlled axes, prevent illegal replication and embedding ownership information in images captured in digital cameras.

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