Robert Goutte

Discrete constrained iterative deconvolution algorithms with optimized rate of convergence

Abstract In this paper, some new constrained discrete deconvolution algorithms based on an iterative equation are presented. The constraints are—the signal extent (signal support)—the positivity—the level bounds. The algorithms minimize either the error energy or a positive functional. The connections with previous works are studied. An experimental comparison of the algorithms convergence speed is studied with a synthetic sequence to be recovered. The restoration error and both the deconvoluted signal and its spectrum show clearly the performances of the algorithms and their ability to achieve a spectral extrapolation. The deconvolution from noisy data is investigated.

Image resolution enhancement using subpixel camera displacement

Abstract Given a CCD camera with its inherent resolution, we would like to get an image with improved resolution using camera displacement. An oversampled image is made by mixing several images with subpixel camera displacement. Finally, a deconvolution technique reduces the low pass filtering effects of the CCD cells, and so improved the image sharpness. The method is tested on computer simulations.

On the use of two-dimensional Wigner-Ville distribution for texture segmentation

Abstract Application of the two-dimensional (2-D) Wigner-Ville (WV) distribution (WVD) to image processing, or more particularly to texture segmentation raises new theoretical and practical problems. This paper tries to formulate the problems in a systematic manner and to develop a set of possible solutions to them. Within this framework, we put emphasis on the reduction of inherent artifacts eventually present in the WVDs of images by giving definite solutions to the problem of interference between positive and negative spatial frequencies, and by proposing, to cope with the problem of interference between the images components, a systematic extension of the most commonly used 1-D (one-dimensional) smoothing techniques to 2-D WVD case. The interest of the proposed solutions is first illustrated with the aid of examples on local WV spectra, and then demonstrated by texture segmentation examples on both synthesized and natural images.

Transformation de wigner-ville: description d’un nouvel outil de traitement du signal et des images

AnalyseLa transformation de Wigner-Ville a fait l’objet, ces dernières années, d’un grand nombre de travaux en traitement du signal et ceci aussi bien sur le plan théorique que dans le domaine des applications. Le but de cet article est de montrer les possibilités offertes par cette transformation, dans sa version discrète, pour les traitements numériques en temps réel de signaux monodimensionnels et des images à 2 ou 3 dimensions.AbstractDuring the last years the Wigner-Ville transform has had an increasing interest in the field of signal processing, as well in theory than in applications. The purpose of this paper is to show the possibilities given by the discrete version of this transformation for real-time processing of monodimensional signals and 2D or 3D images.

The use of a two-dimensional Hilbert transform for Wigner analysis of 2-dimensional real signals

Abstract A method for Wigner analysis of 2-dimensional real signals, based on a 2-dimensional Hilbert transform is proposed. The method allows to obtain a 2-dimensional Wigner distribution which is more easily exploitable than the Wigner distribution of the 2-dimensional real signal. This is shown both by theoretical demonstrations and by examples on simulated and physical images.

Image compression by vector quantization: a review focused on codebook generation

Abstract Recently, vector quantization (VQ) has received considerable attention, and has become an effective tool for image compression. It provides a high compression ratio and a simple decoding process. However, studies on the practical implementation of VQ have revealed some major difficulties such as edge integrity and codebook design efficiency. After reviewing the state-of-the-art in the field of vector quantization, we focus on iterative and non-iterative codebook generation algorithms.

Multiscale reconstruction of tomographic images

The reconstruction of a tomographic image from the wavelet transform of its projections with a given 1-D analyzing wavelet is studied. This procedure permits reconstruction of a 2-D wavelet decomposition of the image. The generated 2-D analyzing wavelet is a radial wavelet, closely related to the 1-D analyzing wavelet. Results for an X-ray computerized tomography scan medical image are presented.<<ETX>>

Equivalence between two-dimensional analytic and real signal Wigner distributions

A solution to the problem of undesired cross-terms in the Wigner distribution (WD) of two-dimensional real signals is presented. The solution is to introduce the notion of two-dimensional analytic signal in the WD. The relation between WDs of the two-dimensional real signal and those of its associated two-dimensional analytical signal is discussed and illustrated by an example. >

Construction of wavelet decompositions for tomographic images

In tomography an image is reconstructed from its projections from different directions. In this paper we study the reconstruction of a tomographic image from the wavelet transform of its projections with a 1-D analyzing wavelet. We then show that it allows us to reconstruct a 2-D wavelet decomposition of the image. The properties of the generated 2-D analyzing wavelet are studied. When the 1-D analyzing wavelet is even, the 2-D analyzing wavelet is isotropic. The extension of this idea to directional wavelets is also presented. The wavelet transform obtained in this case is defined with respect to a scale parameter and a rotation angle. For illustration, results on simulated and x-ray computerized tomography medical images are presented.

Code for encryption hiding data into genomic DNA of living organisms

Recent research has considered DNA an interesting medium for long-term and ultra compact information storage and a stegomedium for hidden messages. Artificial components of DNA with encoded information can be added to the genome of living organisms, such as common bacteria. With this approach, a medium for very height-densities information storage, watermarks for protection patents of genetically modified organisms (GMOs) and secure public keys for decrypting hidden information in steganocryptography, can be obtained. In this paper, we have selected a Bacillus subtilis gene (tatAD ) and use the specific properties of silent mutations to obtain a biologically innocuous product. An adapted code for the message insertion in this gene is proposed.