Nonlinear operators on graphs via stacks

International audienceWe consider a framework for nonlinear operators on functions evaluated on graphs via stacks of level sets. We investigate a family of transformations on functions evaluated on graph which includes adaptive flat and non-flat erosions and dilations in the sense of mathematical morphology. Additionally, the connection to mean motion curvature on graphs is noted. Proposed operators are illustrated in the cases of functions on graphs, textured meshes and graphs of images

Remote Sensing of Venus' atmosphere during the June 2004 transit

Using data from the Venus-Sun transit on 8th of June 2004, one can make estimates about the feasability of making positive spectral detections of biomarkers in extrasolar planet atmospheres. During the transit, transmission spectra from venusian atmospheric layers were measured in three wavelength regions in the near-infrared. Absorption lines of the most abundant molecule CO2 and its isotopes were detected. The line-by-line, high-resolution radiative transfer program SQuIRRL (Schwarzschild Quadrature Infrared Radiation Line-by-line) was used to calculate and validate the observed absorption line