This research work presents a new class of non-blind information hiding algorithms that are stego-secure and robust. They are based on some finite domains iterations having the Devaney’s topological chaos property. Thanks to a complete formalization of the approach we prove security against watermark-only attacks of a large class of steganographic algorithms. Finally a complete study of robustn...

In this paper, the problem of blind separation of underdetermined noisy mixtures of audio sources is considered. The sources are assumed to be sparsely represented in a transform domain. The sparsity of their analysis coefficients is modelled by the Student t distribution. This prior allows for robust Bayesian estimation of the sources, the mixing matrix, the additive noise variance as well as ...

In this paper we compare the performance of several transform coding methods, Discrete Fourier Transform, Discrete Cosine Transform, Wavelets Packet and Karhunen-Loeve Transform, commonly used in image compression systems through experiments. These methods are compared for the effectiveness as measured by rate-distortion ratio and the complexity of computation.

Telemedicine is well known application where enormous amount of medical data need to be transferred securely over network and manipulate effectively. Security of digital data, especially medical images, becomes important for many reasons such as confidentiality, authentication and integrity. Digital watermarking has emerged as a advanced technology to enhance the security of digital images. The...

Telemedicine is well known application where enormous amount of medical data need to be transferred securely over network and manipulate effectively. Security of digital data, especially medical images, becomes important for many reasons such as confidentiality, authentication and integrity. Digital watermarking has emerged as a advanced technology to enhance the security of digital images. The...

In our proposed watermark embedding system, the original audio is segmented into overlapping frames. The psychoacoustic auditory model has been utilized to calculate the global threshold in modified discrete cosine transform domain. The perceptual insignificant locations have been used to insert the appropriately scaled watermark in the transform domain. Blind detection of watermark has been pe...

Realization of focus Speakers produced words differently in the two focus conditions Acoustic features indicate high word prominence Classification Experiments Discrimination of two focus classes with ~65% correct for individual features (acoustic or visual) Exception f0: 65-83% (depending on speaker) Exception nose features: at chance level Significant AV gain when combining energy and FFT or ...

Systolic arrays are a family of parallel computer architectures capable of using a very large number of processors simultaneously for important computations in applications such as scientific computing and signal processing. A discrete cosine transform (DCT) expresses a sequence of finitely many data points in terms of a sum of cosine functions at different frequencies. DCT is a Fourier-related...

A novel single-channel color image encryption algorithm is proposed, which utilizes the reality-preserving fractional discrete cosine transform in YCbCr space. The color image to be encrypted is decomposed into Y, Cb, and Cr components, which are then separately transformed by Discrete Cosine Transform (DCT). The resulting three spectra sequences, obtained by zig-zag scanning the spectra matric...

This paper proposes new image compression technique that uses Real Fourier Transform. Discrete Fourier Transform (DFT) contains complex exponentials. It contains both cosine and sine functions. It gives complex values in the output of Fourier Transform. To avoid these complex values in the output, complex terms in Fourier Transform are eliminated. This can be done by using coefficients of Discr...