Learn More
We outline digital implementations of two newly developed multiscale representation systems, namely, the ridgelet and curvelet transforms. We apply these digital transforms to the problem of restoring an image from noisy data and compare our results with those obtained via well established methods based on the thresholding of wavelet coefficients. We show(More)
We have developed a new ISOCAM data reduction technique based on wavelet analysis, especially designed for the detection of faint sources in mid-infrared surveys. This method, the Pattern REcognition Technique for Isocam data (PRETI) has been used to reduce the observations of the Hubble Deep Field (HDF) and flanking fields with ISOCAM at 6.75 (LW2) and 15(More)
Pulsars are born with subsecond spin periods and slow by electromagnetic braking for several tens of millions of years, when detectable radiation ceases. A second life can occur for neutron stars in binary systems. They can acquire mass and angular momentum from their companions, to be spun up to millisecond periods and begin radiating again. We searched(More)
This article reviews different deconvolution methods. The all-pervasive presence of noise is what makes deconvolution particularly difficult. The diversity of resulting algorithms reflects different ways of estimating the true signal under various idealizations of its properties. Different ways of approaching signal recovery are based on different(More)
  • C J Cesarsky, A Abergel, P Agnèse, B Altieri, J L Augù Eres, H Aussel +60 others
  • 1996
ISOCAM, the camera on–board ISO, takes images of the sky in the wavelength range 2.5 to 18 m. It features two independent channels, containing each a 32 32 pixel detector: the short wavelength channel – 2.5 to 5.5 m, and the long wavelength channel – 4 to 18 m. Each channel features 10 or 11 discrete band pass filters and CVFs with a resolution better than(More)
Before having exhausted the helium in its tank on April 8, 1998, the Infrared Space Observatory had time to perform several complementary surveys at various depths and areas within selected regions of the sky. We present the results of some of the surveys done with the mid-infrared camera, ISOCAM, on-board ISO, and more specifically those surveys which were(More)
  • P Abrial, Y Moudden, J L Starck, B Afeyan, J Bobin, J Fadili +1 other
  • 2007
Morphological Component Analysis (MCA) is a new method which takes advantage of the sparse representation of structured data in large overcomplete dictionaries to separate features in the data based on the diversity of their morphology. It is an efficient technique in such problems as separating an image into texture and piecewise smooth parts or for(More)
Innovative systems for user-computer interaction based on the user's eye-gaze behavior have important implications for various applications. Examples include user navigation in large images, typical of astronomy or medicine, and user selection and viewing of multiple video streams. Typically a web environment is used for these applications. System latency(More)
The Large Area Telescope (LAT), the main instrument of the Fermi Gamma-Ray Space Telescope, detects high energy gamma rays with energies from 20 MeV to more than 300 GeV. The two main scientific objectives, the study of the Milky Way diffuse background and the detection of point sources, are complicated by the lack of photons. That is why we need a powerful(More)
A multiscale representation-based denoising method for spherical data contaminated with Poisson noise, the multiscale variance stabilizing transform on the sphere (MS-VSTS), has been previously proposed. This paper first extends this MS-VSTS to spherical two and one dimensions data (2D-1D), where the two first dimensions are longitude and latitude, and the(More)