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<!--T:2-->
 
<!--T:2-->
Siril is meant to be Iris for Linux (sirI-L). It is an astronomical image processing tool, able to convert, pre-process images, help aligning them automatically or manually, stack them and enhance final images. This page is the page for the new version of Siril.
+
Siril is meant to be Iris for Linux (sirI-L). It is an astronomical image processing tool, able to convert, pre-process images, help aligning them automatically or manually, stack them and enhance final images. In 2017, it also began to work on Mac OS X and Windows.
  
<!--T:21-->
+
<!--T:79-->
'''Current version is [[Siril:0.9.0 rc1|0.9.0 rc1]].''' Previous version was [[Siril:0.9.0 beta|0.9.0 beta]].
+
{{:Siril:Links}}
 +
 
 +
<!--T:60-->
 +
<randomimage size="600" float="center" choices="Lovejoy_300mm_Cyp.jpg|Cassiopeia_Cyp.jpg|Lovejoy_VB.jpg|Lovejoy_Cyp.jpg|Lune-TFG-2014-04-07.jpg|Star-trails.jpg|M33.jpg|NGC7635.jpg|Siril_M8-M20_processed.png|Jupiter.png|Cygnus_loop_fphg.jpg|M27_Cyp.jpg|M33_Cyp.jpg">This image was processed using Siril, see other [[Siril:Results|processing results]].</randomimage>
  
 
==Who should use Siril?== <!--T:22-->
 
==Who should use Siril?== <!--T:22-->
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, but it is not yet as automated as DeepSkyStacker or Registax. It also provides a command line to access various processing functions.
+
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.
  
 
<!--T:24-->
 
<!--T:24-->
Siril is able to process '''planetary''' images (many small images) as well as '''deep sky''' images (a few large images with full pre-processing data). Registration is able to automatically align (translation only) planetary images, using [https://en.wikipedia.org/wiki/Discrete_Fourier_transform DFT], as well as deep-sky images, using [http://en.wikipedia.org/wiki/Point_spread_function PSF] on a reference star, as long as the shift between images in not too large. The manual alignment capability makes it also well fitted for amateur astronomers having bad quality images that automatic tools fail to align properly.
+
Siril is now fully capable to pre-process and process '''deep sky''' images. One feature still missing for '''planetary''' images processing is image deformation, but it is still capable of registering and processing them in an elegant way. The new star detection registration is perfect for deep sky images, but there are also two automatic translation-only registrations, one more suited for planetary and bright nebula images, based on [https://en.wikipedia.org/wiki/Discrete_Fourier_transform Fourier transform], and another more simple targetted at deep-sky images, based on [https://en.wikipedia.org/wiki/Point_spread_function PSF] on a single reference star. Additionally, a manual alignment capability makes it also well fitted for amateur astronomers having feature-less or bad quality images that automatic tools fail to align properly.
  
 
<!--T:25-->
 
<!--T:25-->
Professional astronomers generally use 32-bit depth images, but Siril uses only 16-bit images internally (except temporary for stacking). Loading 32-bit images is supported but it will degrade them since they will be converted to 16-bit. It can still be useful if the intent is to produce public-friendly pictures.
+
Professional astronomers generally use 32-bit depth images, but Siril uses only 16-bit images internally (except temporary for stacking). Loading 32-bit images is supported but it will degrade them since they will be converted to 16-bit (version 1.0 will use at least 32-bit depth channels internally). It can still be useful if the intent is to produce public-friendly pictures.
  
 
<!--T:26-->
 
<!--T:26-->
And more generally, people who want to use free software on free operating systems to process images. Siril can even be used to extract previewed frames from many videos formats. For an overview, see some image processing [[Siril:Results|results]], or [[Siril:Manual|documentation]] pages.
+
And more generally, people who want to use free software on free operating systems to process images. Siril can even be used to extract previewed frames from many videos formats. For an overview, see some image processing [[Siril:Results|results]].
  
 
==News== <!--T:3-->
 
==News== <!--T:3-->
*April 13, 2015
+
For latest updates, see our [https://gitlab.com/free-astro/siril/activity bug and feature tracking system].
**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.
+
 
 +
<!--T:64-->
 +
'''We are looking for volunteer translators''', for the software and for the documentation. No programming experience is required. See the [[Siril:translate|translation instructions]] page for software translation. In any case, check the status of your language translation with cyril (at free-astro.org) if you want to help.
 +
 
 +
<!--T:45-->
 +
The software is now considered stable. If you find a bug and want to report it (please, do!), feel free to report it on the [https://gitlab.com/free-astro/siril/issues bug report page].
 +
 
 +
<!--T:81-->
 +
*'''May 27, 2019'''
 +
** The new [[Siril:0.9.11|0.9.11]] version has been released. This version contains a new photometric color calibration tool, a lot of bug fixes and optimization.
 +
 
 +
<!--T:76-->
 +
*'''January 16, 2019'''
 +
** The new [[Siril:0.9.10|0.9.10]] version has been released, with bug fixes, and new astrometry tool feature.
 +
 
 +
<!--T:80-->
 +
*'''November 26, 2018'''
 +
** Insight has landed! But the Siril news here is that we migrated our source code and bug management system to gitlab! Please use this modern way of communicating with us about code and problems now. The address of the project is https://gitlab.com/free-astro/siril/ . It's been a long year for us with many unfinished business for the 1.0 version. In the meantime, we are preparing a [[Siril:0.9.10|0.9.10]] stability release for very soon.
 +
 
 +
<!--T:78-->
 +
*'''June 7, 2018'''
 +
** The new [[Siril:0.9.9|0.9.9]] version has been released, with bug fixes, and new script feature.
  
<!--T:55-->
+
<!--T:74-->
*December 29, 2014; committed revision 737
+
*February 19, 2018
**First [[Siril:0.9.0 rc1|release-candidate]] of Siril. Previous version was [[0.9.0 beta]].
+
** A patch of the [[Siril:0.9.8|0.9.8]] version has been released: 0.9.8.3.
  
<!--T:54-->
+
<!--T:75-->
*December 10, 2014; committed revision 707
+
*January 31, 2018
**Fixing critical bug in percentile clipping
+
** The new [[Siril:0.9.8|0.9.8]] version has been released, with bug fixes, improvements on lucky imaging and Windows integration.
  
<!--T:48-->
+
<!--T:71-->
*December 5, 2014; committed revision 694
+
*December 4, 2017
**A button has been implemented in order to stop the background process
+
** A new 0.9.8 version is [https://gitlab.com/free-astro/siril/milestones/11 progressing well] and will particularly help people working on deep-sky lucky imaging.
 +
** We have also started working on features for the next major version of Siril, '''version 1.0'''. The first development, started at the beginning of the year, aims to greatly speed up the display of images and the rendering effects and this looks very promising. Other major developments will be the use of a better precision, floating point, internal image format that will give better results with some algorithms, the parallelisation of preprocessing and the creation of a high quality registration and stacking method for planetary images. It will still take a lot of time, but that will be a fully featured and fast version of Siril. Current 0.9.x versions are stable and already provide great results for deep-sky image processing.
  
<!--T:50-->
+
<!--T:70-->
*November 30, 2014; committed revision 678
+
*September 21, 2017
**Starting development of a multi-threaded application for heavy computation. There is a new thread for long tasks, keeping the GUI responsive. This commit implements it in the preprocessing.
+
**New release [[Siril:0.9.7|0.9.7]]. Click [[Siril:releases|here]] for past releases. Siril is now available on '''Windows''' as a beta version!
  
<!--T:51-->
+
<!--T:69-->
*November 29, 2014; committed revision 677
+
*June 20, 2017
**Fixing bug in spline algorithm for background extraction
+
**New release [[Siril:0.9.6|0.9.6]]. Click [[Siril:releases|here]] for past releases.
  
<!--T:52-->
+
<!--T:68-->
*November 27, 2014; committed revision 674
+
*November 28, 2016
**Big update with a bug fixed in the background extraction module. Also the spline algorithm has been improved.  
+
**New release [[Siril:0.9.5|0.9.5]]. Click [[Siril:releases|here]] for past releases. Development of major improvements such as native 32 bit images and GEGL rendering has started.
**New module to remove Canon banding (same algorithm as the script used in PixInsight)
 
  
<!--T:53-->
+
<!--T:66-->
*November 11, 2014; committed revision 671
+
*October 8, 2016
**First beta and package [[Siril:0.9.0 beta|release]] of the new Siril. Previous version was known as [[Siril:0.9_alpha|0.9 alpha]] and was not released outside subversion.
+
**A new team member has given a huge effort to bring you a fantastic new multi-language documentation, both [https://free-astro.org/siril_doc-en/ browsable] and in [https://free-astro.org/download/siril-doc-0.9.9-en.pdf PDF].
  
<!--T:42-->
+
<!--T:65-->
*November 8, 2014; committed revision 659
+
*August 17, 2016
**Fourier Transform module now accepts color images.
+
**New release [[Siril:0.9.4|0.9.4]]. Click [[Siril:releases|here]] for past releases.
  
<!--T:43-->
+
<!--T:57-->
*November 2, 2014; committed revision 643
+
*October 28, 2015
**New rejection stacking process for small set of data: Percentile Clipping.
+
**First stable version available: [[Siril:0.9.0|0.9.0]]. Stability updates and minor improvements will occur in the dedicated 0.9 branch.
  
<!--T:44-->
+
<!--T:58-->
*October 31, 2014; committed revision 641:
+
*June 10, 2015
**Fixing critical bug in Winsorized Sigma Clipping.
+
**New registration method available! It is now possible to register images with an automatic global star detection tool. The algorithm takes into account the translation and the rotation.
**Fixing rejected pixels count.
 
  
<!--T:45-->
+
<!--T:56-->
The software is in '''beta''' phase, meaning its stability is still being improved, but most functionalities are working. If you find bugs and want to report them (please, do!), contact the team using the links at the bottom of this page, or use the system provided by your OS.
+
*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.
  
 
<!--T:47-->
 
<!--T:47-->
Many [[Siril:0.9.0 beta|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 [[Siril:Commands|Commands]] page. New commands and features have been and are being developed. For a complete list of features, see the [[Siril:0.9.0_beta|0.9.0 beta]] page, the subversion log, or the [[Siril#List_of_Siril_features|list of features]] below.
+
Many [[Siril:0.9.7|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 [[Siril:Commands|Commands]] page. New commands and features have been and are being developed. For a complete list of features, see the [[Siril:0.9.7|0.9.7]] page, [https://gitlab.com/free-astro/siril/milestones/10 the roadmap], or the [[Siril#List_of_Siril_features|list of features]] below.
  
 
<!--T:12-->
 
<!--T:12-->
The '''roadmap''' for Siril is being updated for its after-release life. The main coming developments are completely remaking the conversion and sequence features to handle any list of files, and providing a registration that takes image rotation into account. Ideas are stored in the [https://free-astro.vinvin.tf/svn/siril/src/TODO TODO] file, and the list of known bugs is maintained in the [https://free-astro.vinvin.tf/svn/siril/src/BUGS BUGS] 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 [https://free-astro.vinvin.tf/svn/siril/ChangeLog ChangeLog] file. '''If you want to contribute, you are welcome!'''
+
Ideas for the future of Siril are stored in the issues tracking system and can be seen by version in the [https://gitlab.com/free-astro/siril/milestones milestones page]. The list of known bugs is mixed with it and the full list is available [https://gitlab.com/free-astro/siril/issues here]. The complete changelog is available either in the [https://gitlab.com/free-astro/siril/issues?scope=all&utf8=%E2%9C%93&state=closed list of closed bugs] or in the [https://gitlab.com/free-astro/siril/commits/master code source commits]. A summary is available in the news section [[#News|above]] and in the page of each release, as well as in the [https://gitlab.com/free-astro/siril/blob/master/ChangeLog ChangeLog] file. '''If you want to contribute, you are welcome!'''
  
 
==Start using Siril / Documentation== <!--T:4-->
 
==Start using Siril / Documentation== <!--T:4-->
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 [[Siril:Tutorial_import|Conversion tab]], except for SER and film sequences which are converted on-the-fly.
+
Siril's works internally with [https://en.wikipedia.org/wiki/FITS FITS] images, unsigned 16-bit per pixel and per channel. Some [[Siril:supported_FITS|other FITS formats]] are supported. All other image formats you want to process with Siril have to be converted using the Conversion tab, but some sequence files are converted on-the-fly: [[SER]] and film sequences supported by ffmpeg (which means nearly all films).  
  
 
<!--T:27-->
 
<!--T:27-->
 
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.
 
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.
 +
 +
<!--T:72-->
 +
A free [https://siril.linux-astro.fr/ online course for siril] has been set-up and new content is added regularly. Most uses of Siril will be described here with short films and exercices that allow you to learn by yourself and make sure you understood on concrete examples.
  
 
<!--T:28-->
 
<!--T:28-->
A '''[[Siril:Manual|documentation page]]''' contains an illustrated [[Siril:Manual#Tutorial_for_a_complete_sequence_processing|complete processing tutorial]], instructions on how to use particular features of Siril, along with a few videos to illustrate or describe these capabilities.
+
'''A [//{{SERVERNAME}}/siril_doc-en/ Web-based documentation]''' or '''[//{{SERVERNAME}}/download/siril-doc-0.9.9-en.pdf PDF format]''' for offline viewing, contain illustrated instructions on how to use particular features of Siril, along with a few videos to illustrate or describe these capabilities.
  
 
<!--T:5-->
 
<!--T:5-->
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New features are being introduced quite regularly. Here is a list of main features:
 
New features are being introduced quite regularly. Here is a list of main features:
 
* Native image format support
 
* Native image format support
** unsigned 16-bit FITS files (other FITS are converted to this format on-the-fly)
+
** Unsigned 16-bit FITS files ([[Siril:supported_FITS|other FITS]] are converted to this format on-the-fly)
** SER files
+
** [[SER]] files
** AVI and many other film files
+
** AVI and many other film files, their support is being dropped in favour of SER.
 
* Image conversion (to the native FITS format only)
 
* 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.
 
** Supported input types: 8-bit and 16-bit BMP, TIFF, JPEG, PNG files, NetPBM binary images, RAW DSLR images.
 +
* Pre-processing of images with multi-channel offset, dark and flat images
 
* Image registration; supported methods:
 
* Image registration; supported methods:
** Translation using DFT centered on an object, generally used for planetary images
+
** Global star alignment (rotation + translation)
** Translation using PSF of a star, generally used for deek-sky images
+
** Translation using DFT centred on an object, generally used for planetary images
 +
** Translation using PSF of a star, generally used for deep-sky images
 
** Manual translation with two preview renderings of the current image with reference frame in transparency
 
** Manual translation with two preview renderings of the current image with reference frame in transparency
** Image rotation and plate-solving are not implemented yet
+
* Registered sequence export
* Image stacking
+
** Supported export file formats: Siril FITS sequence, SER sequence, uncompressed AVI files, GIF up to 0.9.4, MP4 and WEBM web publishing video formats since 0.9.5
 +
** Optional cropping and resizing of the exported images
 +
* Image stacking, with optional additive or multiplicative normalization
 
** Summing
 
** Summing
 
** Median
 
** Median
** Percentile clipping
+
** Average with rejection (percentile, sigma, median, Winsorized and linear fit clipping)
** Sigma clipping
+
** Pixel minimum or maximum across images
** Median sigma clipping
+
* Enhancement and processing of final images
** Winsorized sigma clipping
+
** Lightness/contrast cursors on each layer, different scaling modes (linear, log, square root, squared, asinh, histogram equalisation), negative and false colour rendering and clipping
** Linear fit clipping
+
** Background removal tool
** Pixel maximum
+
** Cosmetic correction tool
* Pre-processing of images with multi-channel offset, dark and flat images
+
* A command line for various processing functions, only available from the GUI, see the list of [[Siril:Commands|available commands]].
* 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 [[Siril:Commands|available commands]].
 
 
* A star finding algorithm with PSF information
 
* A star finding algorithm with PSF information
 
+
* Image compositing tool, combining and aligning multiple layers (2 to 6) with custom colours into a resulting image, with luminance layer support
<!--T:13-->
+
* Plotting various pieces of information about an image sequence (FWHM, star roundness, periodic error of the mount, amplitude, background level...)
'''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 many 1-channel image to create a colour composition, such as popular LRGB, RGBHa or [http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/eagle.php SII-Ha-OIII] images.
 
  
 
==Compilation and installation== <!--T:15-->
 
==Compilation and installation== <!--T:15-->
  
 
<!--T:16-->
 
<!--T:16-->
Since 0.9.0b, Siril is released as source package or binary package in various distributions. The other choice is accessing the development trunk in the subversion repository. There is a package for the Arch Linux system, built from the subversion source, [https://aur.archlinux.org/packages/siril/ in AUR]. Siril has also been tested and reported running on MacOS but needs a specific installation, please see the [[Siril:install#Installing_on_MacOS|dedicated page]].
+
See [[Siril:install|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.
 
 
===Dependencies=== <!--T:29-->
 
Siril depends on a number of libraries, which all should be available in your operating system if it is recent enough. See a list of packages names for Debian [[Siril:install|here]]. Mandatory dependencies are:
 
* [http://www.gtk.org/ gtk+-3.6] (Graphical user interface library)
 
* [http://heasarc.nasa.gov/fitsio/fitsio.html cfitsio] (FITS images support)
 
* [http://www.fftw.org/ fftw] (Discrete Fourier Transform library)
 
* [http://www.gnu.org/software/gsl/ gsl] (The GNU Scientific Library)
 
* [http://www.hyperrealm.com/libconfig/ libconfig]++ (Structured configuration files support)
 
 
 
<!--T:30-->
 
Optional dependencies are:
 
* [http://www.libraw.org/ libraw], [http://www.libtiff.org/ libtiff], [http://libjpeg.sourceforge.net/ libjpeg], [http://libpng.sourceforge.net/index.html libpng] for RAW, TIFF, JPEG and PNG images import and export. The libraries are detected at compilation-time.
 
* [https://github.com/FFMS/ffms2 FFMS2] for film native support as image sequences. It also allows frames to be extracted from many kinds of film, for other purposes than astronomy. Versions < 2.20 have an annoying bug. It is recommanded to install the last version.
 
* [http://opencv.org/ OpenCV] and a C++ compiler for binned image resizing in the LRGB composition tool. Without it, only images the same size can be composed. It is also used to rotate images in the rotation tool (not yet in registration).
 
 
 
===Installation instructions=== <!--T:32-->
 
This section describes how to build Siril from source. For binary packages or dependencies, see the [[Siril:install|install documentation]] page, or the current version link at the top of the page.
 
 
 
<!--T:46-->
 
Get the subversion repository using this command:
 
 
 
<!--T:17-->
 
<tt>$ svn --trust-server-cert co https://free-astro.vinvin.tf/svn/siril/</tt>
 
 
 
<!--T:18-->
 
''(sorry for the bad certificate)''. The source is read-only if you have no particular authorization. If you want to '''participate''' to Siril and be able to commit on the svn, send a message to user [[User:Vincent|Vincent]] here.
 
 
 
<!--T:19-->
 
Once you have got Siril's source code, it's easy to install it. Siril is managed with autotools, so it's simply built using ./configure and make. If you don't have autotools or other development packages, see this [[Siril:install|install documentation]]. The configure script is not shipped to allow for better interoperability and can be generated using this command:
 
 
 
<!--T:33-->
 
<tt>$ aclocal && autoconf && autoheader && automake --add-missing</tt>
 
  
<!--T:34-->
+
<!--T:73-->
Then run ./configure and make. To install Siril, with the correct rights, use the usual:
+
To install standalone binaries, please go to [[Siril:releases|this page]], choose the last version and download the binary corresponding to your OS.
 
 
<!--T:35-->
 
<tt>$ make install</tt>
 
 
 
<!--T:36-->
 
To launch Siril, the command name is <code>siril</code>.
 
  
 
==Who is behind Siril?== <!--T:37-->
 
==Who is behind Siril?== <!--T:37-->
  
 
<!--T:38-->
 
<!--T:38-->
The project leader of this new version is [[User:Vincent|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.
+
[[User:Vincent|Vincent]] is a computer scientist (PhD) and uses Siril as an amateur to process images from a Canon EOS, a QSI and a Basler camera on a 410mm telescope.
  
 
<!--T:39-->
 
<!--T:39-->
[[User:Lock42|Cyril]] is a physicist (PhD), motivating new developments and providing high quality processing algorithms to Siril.
+
[[User:Lock42|Cyril]] is a physicist (PhD), now IT engineer at CNRS, motivating new developments and providing high quality processing algorithms to Siril.
 +
 
 +
<!--T:67-->
 +
Laurent is a senior IT project manager and also uses Siril to process images from a Canon EOS and a ZWO camera on a 254mm telescope. He manages the formatting of the documentation, using Scenari technology and the Moodle online training.
  
 
<!--T:41-->
 
<!--T:41-->
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<!--T:40-->
 
<!--T:40-->
See the [https://free-astro.vinvin.tf/svn/siril/AUTHORS AUTHORS] file for the complete list of contributors.
+
See the [https://gitlab.com/free-astro/siril/blob/master/AUTHORS AUTHORS] file for the complete list of contributors.
 +
 
 +
<!--T:59-->
 +
If you like the software, please help us by contributing with the Donate button on the top right. Siril takes us a lot of time and we still have to pay for the servers.
 
</translate>
 
</translate>

Latest revision as of 11:01, 27 May 2019

Other languages:
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Siril, a free astronomical image processing software

Siril is meant to be Iris for Linux (sirI-L). It is an astronomical image processing tool, able to convert, pre-process images, help aligning them automatically or manually, stack them and enhance final images. In 2017, it also began to work on Mac OS X and Windows.

<translate>

</translate>


This image was processed using Siril, see other processing results.


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 is now fully capable to pre-process and process deep sky images. One feature still missing for planetary images processing is image deformation, but it is still capable of registering and processing them in an elegant way. The new star detection registration is perfect for deep sky images, but there are also two automatic translation-only registrations, one more suited for planetary and bright nebula images, based on Fourier transform, and another more simple targetted at deep-sky images, based on PSF on a single reference star. Additionally, a manual alignment capability makes it also well fitted for amateur astronomers having feature-less or bad quality images that automatic tools fail to align properly.

Professional astronomers generally use 32-bit depth images, but Siril uses only 16-bit images internally (except temporary for stacking). Loading 32-bit images is supported but it will degrade them since they will be converted to 16-bit (version 1.0 will use at least 32-bit depth channels internally). It can still be useful if the intent is to produce public-friendly pictures.

And more generally, people who want to use free software on free operating systems to process images. Siril can even be used to extract previewed frames from many videos formats. For an overview, see some image processing results.

News

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

We are looking for volunteer translators, for the software and for the documentation. No programming experience is required. See the translation instructions page for software translation. In any case, check the status of your language translation with cyril (at free-astro.org) if you want to help.

The software is now considered stable. If you find a bug and want to report it (please, do!), feel free to report it on the bug report page.

  • May 27, 2019
    • The new 0.9.11 version has been released. This version contains a new photometric color calibration tool, a lot of bug fixes and optimization.
  • January 16, 2019
    • The new 0.9.10 version has been released, with bug fixes, and new astrometry tool feature.
  • November 26, 2018
    • Insight has landed! But the Siril news here is that we migrated our source code and bug management system to gitlab! Please use this modern way of communicating with us about code and problems now. The address of the project is https://gitlab.com/free-astro/siril/ . It's been a long year for us with many unfinished business for the 1.0 version. In the meantime, we are preparing a 0.9.10 stability release for very soon.
  • June 7, 2018
    • The new 0.9.9 version has been released, with bug fixes, and new script feature.
  • February 19, 2018
    • A patch of the 0.9.8 version has been released: 0.9.8.3.
  • January 31, 2018
    • The new 0.9.8 version has been released, with bug fixes, improvements on lucky imaging and Windows integration.
  • December 4, 2017
    • A new 0.9.8 version is progressing well and will particularly help people working on deep-sky lucky imaging.
    • We have also started working on features for the next major version of Siril, version 1.0. The first development, started at the beginning of the year, aims to greatly speed up the display of images and the rendering effects and this looks very promising. Other major developments will be the use of a better precision, floating point, internal image format that will give better results with some algorithms, the parallelisation of preprocessing and the creation of a high quality registration and stacking method for planetary images. It will still take a lot of time, but that will be a fully featured and fast version of Siril. Current 0.9.x versions are stable and already provide great results for deep-sky image processing.
  • September 21, 2017
    • New release 0.9.7. Click here for past releases. Siril is now available on Windows as a beta version!
  • June 20, 2017
    • New release 0.9.6. Click here for past releases.
  • November 28, 2016
    • New release 0.9.5. Click here for past releases. Development of major improvements such as native 32 bit images and GEGL rendering has started.
  • October 8, 2016
    • A new team member has given a huge effort to bring you a fantastic new multi-language documentation, both browsable and in PDF.
  • August 17, 2016
    • New release 0.9.4. Click here for past releases.
  • October 28, 2015
    • First stable version available: 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 takes 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 0.9.7 page, the roadmap, or the list of features below.

Ideas for the future of Siril are stored in the issues tracking system and can be seen by version in the milestones page. The list of known bugs is mixed with it and the full list is available here. The complete changelog is available either in the list of closed bugs or in the code source commits. A summary is available in the news section above 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. Some other FITS formats are supported. All other image formats you want to process with Siril have to be converted using the Conversion tab, but some sequence files are converted on-the-fly: SER and film sequences supported by ffmpeg (which means nearly all films).

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.

A free online course for siril has been set-up and new content is added regularly. Most uses of Siril will be described here with short films and exercices that allow you to learn by yourself and make sure you understood on concrete examples.

A Web-based documentation or PDF format for offline viewing, contain illustrated instructions on how to use particular features of Siril, along with a few videos to illustrate or describe these capabilities.

Siril stacking result.png

List of Siril features

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.
  • Pre-processing of images with multi-channel offset, dark and flat images
  • Image registration; supported methods:
    • Global star alignment (rotation + translation)
    • Translation using DFT centred on an object, generally used for planetary images
    • Translation using PSF of a star, generally used for deep-sky images
    • Manual translation with two preview renderings of the current image with reference frame in transparency
  • Registered sequence export
    • Supported export file formats: Siril FITS sequence, SER sequence, uncompressed AVI files, GIF up to 0.9.4, MP4 and WEBM web publishing video formats since 0.9.5
    • Optional cropping and resizing of the exported images
  • Image stacking, with optional additive or multiplicative normalization
    • Summing
    • Median
    • Average with rejection (percentile, sigma, median, Winsorized and linear fit clipping)
    • Pixel minimum or maximum across images
  • Enhancement and processing 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
    • Background removal tool
    • Cosmetic correction tool
  • A command line for various processing functions, only available from the GUI, see the list of available commands.
  • A star finding algorithm with PSF information
  • Image compositing tool, combining and aligning multiple layers (2 to 6) with custom colours into a resulting image, with luminance layer support
  • Plotting various pieces of information about an image sequence (FWHM, star roundness, periodic error of the mount, amplitude, background level...)

Compilation and 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.

To install standalone binaries, please go to this page, choose the last version and download the binary corresponding to your OS.

Who is behind Siril?

Vincent is a computer scientist (PhD) and uses Siril as an amateur to process images from a Canon EOS, a QSI and a Basler camera on a 410mm telescope.

Cyril is a physicist (PhD), now IT engineer at CNRS, motivating new developments and providing high quality processing algorithms to Siril.

Laurent is a senior IT project manager and also uses Siril to process images from a Canon EOS and a ZWO camera on a 254mm telescope. He manages the formatting of the documentation, using Scenari technology and the Moodle online training.

François Meyer wrote the initial (up to v0.8) versions. Here are the legacy Sourceforge project and website.

See the AUTHORS file for the complete list of contributors.

If you like the software, please help us by contributing with the Donate button on the top right. Siril takes us a lot of time and we still have to pay for the servers.