Welcome to Trac 0.11.4

MASMAI: A Multiscale Analysis System for Multiband Astronomical Images

The joint analysis of a set of images obtained with different spectral bands is an important challenge for today’s Astronomy. The main goal is the identification of astrophysical sources and their characterization in all bands. The MASMAI software is being developed for that purpose. The images are supposed to correspond geometrically. It will be organized into five parts:

Fusion level

  • Noise variance estimation.

Pyrels and Objects

  • The fusion image is decomposed into scalet coefficients, called pyrels for PYRamidal Elements.
  • For each pyrel the amplitude is then computed for each band.
  • Images are reconstructed for each band from the pyrels.


  • Pyrels are merged in order to define complex objects.
  • The image of each object is constructed for each band, taking into account the amplitudes and the belonging graph.
  • Some physical quantities are computed from these images (position, flux, size, pattern parameters...).


  • Some color indices are determined for pixels or/and for pyrels.
  • Spectral classes are obtained from these indices.


  • Pixels or/and pyrels are decomposed taking into account the spectral energy distribution of the classes.
  • Source images are thus obtained either from the pixels or from the pyrels.
  • The pyrel decomposition allows one to decompose also each object into elementary sources.

This toolbox is being built for the exploitation of this scheme in the context of the virtual observatory.


Here, the specific structure of the programs are described.

The MASMAI1 directory contains a set of useful programs.

Last modified 11 years ago Last modified on Nov 4, 2009 3:52:01 PM