Siril/fr

Siril, un logiciel libre pour le traitement d'images en astronomie

Siril était supposé être Iris pour Linux (sirI-L). C'est un outil de traitement d'images pour l'astronomie, capable de convertir, pré-traiter, d'aligner manuellement ou automatiquement, d'empiler et d'améliorer le rendu final d'une séquence d'images. Cette page présente la nouvelle version de Siril.

La version actuelle est 0.9.0. Les versions précédentes étaient 0.9.0 beta et 0.9.0 rc1, devenues obsolètes.

Who should use Siril?

Siril is targeted to amateur astronomers having acquired images and wanting to process them in a semi-automatic way. It provides a more user-friendly interface than Iris' command line as well as more modern and powerful processing algorithms, but it is not yet as automated as DeepSkyStacker or Registax. It also provides a basic command line to access various processing functions.

Siril est maintenant pleinement capable de pré-traiter et traiter des images de ciel profond. Une fonctionnalité encore manquante pour le traitement des images planétaires est la déformation d'images, mais il est quand même capable de les registrer et traiter d'une façon élégante. La nouvelle registration basée sur les détections d'étoiles est parfaite pour les images de ciel profond, mais il y a aussi deux registrations automatiques qui ne prennent en compte que les translations, une plus adaptée au planétaire et aux nébuleuses lumineuses, utilisant une transformée de Fourier discrète, une autre plus simple ciblant les images de ciel profond, utilisant la PSF sur une étoile de référence, il ne faut donc pas un décalage trop important des images. La fonctionnalité d'alignement manuel rend Siril aussi utile aux astronomes amateurs ayant des images de mauvaise qualité ou plus généralement pour lesquelles les logiciels automatisés ont le plus de mal à trouver les points d'alignement.

Les astronomes professionnels utilisent généralement des images en 32 bits par pixel par couleur ; Siril n'en utilise que 16 en interne (sauf de façon temporaire pour l'empilement). Le chargement des images FITS en 32 bits est supporté mais elles seront dégradées puisque converties en 16 bits. Cela peut être quand même utile si le but est de produire des images pour le grand public.

Et en général, les personnes qui veulent utiliser un logiciel libre sur un système d'exploitation libre pour traiter des images. Siril peut même être utilisé pour extraire des images de la plupart des vidéos, en les prévisualisant. Pour un aperçu, voir quelques traitements faits avec Siril, ou la documentation.

News

For latest updates, see our bug and feature tracking system.

The software is in released phase, and is now considered stable. If you find bugs and want to report them (please, do!), contact the team using the links at the bottom of this page, or feel free to report them on the bug report page.

• October 28, 2015
  • First stable version available. Its SVN revision is 1037, but it also has an SVN tag: 0.9.0. Stability updates and minor improvements will occur in the dedicated 0.9 branch.

• June 10, 2015
  • New registration method available!! It is now possible to register images with an automatic global star detection tool. The algorithm take into account the translation and the rotation.

• April 13, 2015
  • We have been working hard on accelerating stacking algorithms on multi-core CPUs, giving SER a better support and we are also working on the two main lacks of Siril: taking into account rotation and multi-point in registration, for better deep-sky and planetary registrations. These works are in progress, and will take some weeks to complete.

Many improvements have been done over the previous unmaintained version. The command line has been reactivated in large proportions, see the list of currently available commands on the dedicated Commands page. New commands and features have been and are being developed. For a complete list of features, see the 0.9.0 beta page, the roadmap, or the list of features below.

The roadmap for Siril is being updated for its after-release life. Ideas are stored in the Roadmap page, and the list of known bugs is maintained in the bug tracking page file. The complete changelog is available in the SVN log (not available online), a summary is available in the news section here and in the page of each release, as well as in the ChangeLog file. If you want to contribute, you are welcome!

Start using Siril / Documentation

Siril's works internally with FITS images, unsigned 16-bit per pixel and per channel. All images you want to process with Siril thus needs to be converted using the Conversion tab, except for SER and film sequences which are converted on-the-fly.

For pre-processing, Siril applies master offset/bias, dark and flat images to the current sequence. These master images thus have to be processed before processing the actual image sequence. Siril currently does not support processing multiple sequences at the same time, so each layer of the final image must be processed independently before assembling them into an RGB image.

Une page de documentation contient un tutoriel complet de traitement illustré, des instructions sur comment utiliser des fonctionnalités particulières de Siril, et des vidéos qui illustrent ces dernières.

Liste des fonctionnalités de Siril

New features are being introduced quite regularly. Here is a list of main features:

• Native image format support
  • unsigned 16-bit FITS files (other FITS are converted to this format on-the-fly)
  • SER files
  • AVI and many other film files, their support is being dropped in favour of SER.
• Image conversion (to the native FITS format only)
  • Supported input types: 8-bit and 16-bit BMP, TIFF, JPEG, PNG files, NetPBM binary images, RAW DSLR images.
• Image registration; supported methods:
  • Global star alignment (rotation + translation)
  • Translation using DFT centered on an object, generally used for planetary images
  • Translation using PSF of a star, generally used for deek-sky images
  • Manual translation with two preview renderings of the current image with reference frame in transparency
• Image stacking
  • Summing
  • Median
  • Percentile clipping
  • Sigma clipping
  • Median sigma clipping
  • Winsorized sigma clipping
  • Linear fit clipping
  • Pixel maximum
• Pre-processing of images with multi-channel offset, dark and flat images
• Enhancement of final images: lightness/contrast cursors on each layer, different scaling modes (linear, log, square root, squared, asinh, histogram equalisation), negative and false colour rendering and clipping.
• A command line for various processing functions, see the list of available commands.
• A star finding algorithm with PSF information

Limitations:

• Only 3-channel colour images assigned to R, G and B are possible in the general workspace (image processing and sequence handling). It is however possible to manipulate several 1-channel image to create a colour composition, such as popular LRGB, RGBHa or SII-Ha-OIII images, with the compositing tool.

Compilation et installation

See Siril installation page. It documents which binary packages you can get and how to build from source if needed, for multiple operating systems. Siril is a free software, licence is GPL3. It will most likely never run or be supported on Windows family operating systems.

Qui est derrière Siril ?

The project leader of this new version is Vincent. He is a computer scientist (PhD), and uses Siril as an amateur to process images from a Canon EOS and a B&W QSI camera on a 410mm telescope.

Cyril est docteur en physique ; il motive les nouveaux développement et fournit des algorithmes de traitements de haute qualité à Siril.

François Meyer a développé le projet initial, jusqu'à la version 0.8. Ici sont téléchargeables les sources devenues obsolètes : Sourceforge project et website.

See the AUTHORS file for the complete list of contributors.