Showing papers by "Albert Bijaoui published in 1994"
TL;DR: A new approach for filtering based on the wavelet transform is presented, and several algorithms are proposed, and a criterion of quality, which takes into account the resolution, is used to compare these algorithms.
116 citations
Journal Article•
TL;DR: In this article, a multiresolution deconvolution is performed for the interferometric images by using the CLEAN method on the wavelet coefficients, assuming the existence of a solution which satisfies the positivity and the limited support constraints, and which is compatible with the measured visibilities.
Abstract: The Wavelet Transform is a tool which allows us to get information both in the direct space and in the frequency space. We have developed an algorithm based on the FFT with an isotropic wavelet. A multiresolution deconvolution is performed for the interferometric images by using the CLEAN method on the wavelet coefficients. An iterative reconstruction assumes the existence of a solution which satisfies the positivity and the limited support constraints, and which is compatible with the measured visibilities. By this method, the images of two evolved stars have been reconstructed from infrared speckle interferometry observations
39 citations
30 Sep 1994
TL;DR: In this article, the notion of a multiresolution support is introduced, where a sequence of boolean images related to significant pixels at each of a number of resolution levels are used for noise suppression, in the context of iterative image restoration.
Abstract: The notion of a multiresolution support is introduced. This is a sequence of boolean images, related to significant pixels at each of a number of resolution levels. The multiresolution support is then used for noise suppression, in the context of iterative image restoration. Algorithmic details and examples illustrate this approach.
18 citations
01 Jan 1994
TL;DR: In this article, a methode iterative de restauration des images basee on the notion of coefficients significatifs is proposed. But this methode is not applicable to the problem of deconvolution.
Abstract: La transformation en ondelettes discrete peut etre realisee par differents algorithmes. Parmi ceux-ci, l'algorithme a trous conduit a une importante redondance de donnees. Si cette redondance le rend impraticable pour la compression des signaux, elle peut etre, au contraire, un atout pour la restauration des images. Dans cet article nous exposerons tout d'abord les fondements de cet algorithme et les divers outils associes (transformation, inversion, visualisation). Nous developperons ensuite une methode iterative de restauration des images basee sur la notion de coefficients significatifs. La reduction des coefficients conduit a regulariser le problleme inverse lie a la deconvolution. Un exemple est donne en se basant sur l'inversion par la methode de Richardson-Lucy
13 citations