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Publication in the conference proceedings of EUSIPCO, Toulouse, France, 2002
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Block matching along epipolar lines is the core of most stereovision algorithms in geographic information systems. The usual distances between blocks are the sum of squared distances in the block (SSD) or the correlation. These distances... more
Block matching along epipolar lines is the core of most stereovision algorithms in geographic information systems. The usual distances between blocks are the sum of squared distances in the block (SSD) or the correlation. These distances suffer the adhesion (or fattening) effect, a defect by which the center of the block inherits the disparity of the more contrasted pixels in the block. This report shows that there is a simple and universal solution to this problem. It is enough to use an adaptive weight in the SSD. This weight is nothing but the square of the gradient of the first image in the epipolar direction. This magic adaptive weight yields a computed disparity which is the result of a convolution of the real disparity with a fixed kernel. The choice of the kernel is left to the user. Experiments on simulated and real pairs prove that the formula applies really, and eliminates surface bumps clearly due to the adhesion phenomenon.
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Research Interests: Mathematics, Computer Science, Artificial Intelligence, Image Processing, Remote Sensing, and 12 moreSignal Processing, Inverse Problems, Wavelet Transforms, Noise reduction, Image Restoration, Degradation, Inverse Problem, High resolution satelite image, Modulation Transfer Function, Deblurring, White Noise, and Wavelet Packet Decomposition
ABSTRACT Present soil moisture and ocean salinity maps retrieved by remote sensing are characterized by a coarse spatial resolution. Hydrological, meteorological and climatological applications would benefit greatly from a better spatial... more
ABSTRACT Present soil moisture and ocean salinity maps retrieved by remote sensing are characterized by a coarse spatial resolution. Hydrological, meteorological and climatological applications would benefit greatly from a better spatial resolution. Owing to the dimensions of the satellite structure and to the degradation of the instrument's radiometric sensitivity, such improvement cannot be achieved with classical interferometry. Then, in order to achieve this goal an original concept for passive interferometric measurements is described. This concept should allow to achieve a much finer spatial resolution, which can be further improved with the application of disaggregation methods. The results will then allow the integration of global soil moisture maps into hydrological models, a better management of water resources at small scales and an improvement in spatial precision for various applications.
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ABSTRACT This paper describes an original method to identify microvibrations of satellite platforms using only a pair of stereo images. Image pairs contain a twofold information: the landscape details and the platforrn microvibration... more
ABSTRACT This paper describes an original method to identify microvibrations of satellite platforms using only a pair of stereo images. Image pairs contain a twofold information: the landscape details and the platforrn microvibration corruptions (roll, pitch and yaw). We propose identification methods in the case of a push-broom acquisition mode with a 6000 pixel CCD linear array (in the case of the French satellite SPOT). This method relies on the image acquisition principle, on the nature of the observed landscape and finally on some concepts of surface geometry. The algorithms providing such identification have been implemented and applied to simulated data, based on a true digital model terrain of Marseille (France). The results of our vibration identification method are presented here. Comparisons with traditional methods are also presented in this paper.
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ABSTRACT New mathematical results about extrapolation of an image spectrum yield an efficient algorithm for superresolution in image processing. A significant power resolution is gained with the help of a new nonlinear interpolation... more
ABSTRACT New mathematical results about extrapolation of an image spectrum yield an efficient algorithm for superresolution in image processing. A significant power resolution is gained with the help of a new nonlinear interpolation method. The principle of this new method is described and illustrated by the treatment of (small) real images.
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... for Multiresolution Satellite Image Coding Marc ANTONlNl *, Michel BARLAUD Bernard ROUGE **, Catherine LAMBERT-NEBOUT ** ** : Laboratoire I3S/CNRS - Universite de Nice - Sophia Antipolis (France). : Centre National d'Etudes... more
... for Multiresolution Satellite Image Coding Marc ANTONlNl *, Michel BARLAUD Bernard ROUGE **, Catherine LAMBERT-NEBOUT ** ** : Laboratoire I3S/CNRS - Universite de Nice - Sophia Antipolis (France). : Centre National d'Etudes Spatiales de Toulouse (France). ...
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ABSTRACT Acquiring good quality images of moving objects by a digital camera remains a valid question. If the velocity of the photographed object is not known, it is virtually impossible to tune an optimal exposure time. For this reason... more
ABSTRACT Acquiring good quality images of moving objects by a digital camera remains a valid question. If the velocity of the photographed object is not known, it is virtually impossible to tune an optimal exposure time. For this reason the recent Agrawal et al. flutter shutter apparatus has generated much interest. In this communication, we propose a mathematical formalization of a general flutter shutter method, also permitting non-binary shutter sequences. Thanks to this formalization, the question of the optimal flutter shutter code can be defined and solved. The method gives analytic formulas for the best attainable SNR for the restored image. It also gives a way to compute optimal flutter shutter codes.
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Research Interests: Cartography, Mathematics, Geodesy, Geophysics, Computer Science, and 15 moreDigital Elevation Models, Geoscience and remote sensing, Image Reconstruction, Geoscience, Image Retrieval, DEM, Geomatic Engineering, Image Interpolation, Interpolation, Digital Elevation Model, Layout, Boolean Satisfiability, Electrical And Electronic Engineering, Geodesic Distance, and Interpolation Method
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We propose an algorithm to increase the resolution of satellite multispectral images knowing the panchromatic image at high resolution and the spectral channels at lower resolution. Our algorithm is based on the assumption that, to a... more
We propose an algorithm to increase the resolution of satellite multispectral images knowing the panchromatic image at high resolution and the spectral channels at lower resolution. Our algorithm is based on the assumption that, to a large extent, the geometry of the spectral channels is contained in the topographic map of its panchromatic image. This assumption, together with the relation relating the panchromatic image to the spectral channels, and the expression of the low resolution pixel in terms of the high resolution pixels given by some convolution kernel followed by subsampling, constitute the elements to construct an energy functional whose mimima will give the reconstructed spectral images at higher resolution. We shall discuss the well foundedness of the above approach and describe our numerical approach. Finally some experiments are displayed.