Introduction #

We are pleased to announce the release of Siril 1.4.5!

This maintenance release is the largest of the 1.4.x series so far. It brings a long list of bug fixes covering stacking, live stacking, file formats, astrometry, photometry, display and Python scripting, together with a few welcome improvements: editing the FITS keywords of a whole sequence and a faster banding reduction.

What’s new in Siril 1.4.5 #

Improvements #

• Editing FITS keywords of a whole sequence: when a sequence is loaded, keyword edits made in the FITS header dialog can now be applied, after confirmation, to every image of the sequence
• Faster banding reduction (!1097): the algorithm has been reimplemented for improved speed, and the arguments of the fixbanding and seqfixbanding commands have been reviewed (-vert is now accepted as a short form of -vertical)
• New SirilInterface.is_headless property (!1111): Python scripts can check it to avoid opening a GUI when Siril runs without a graphical interface

Bug fixes #

Stacking and preprocessing #

• Fixed GESDT rejection (#1993): the two most extreme samples of each pixel were always rejected whatever their significance, and the neighbour of a high outlier could be rejected instead of the outlier itself
• Fixed the stack command refusing rejection parameters in scientific notation (#1993), such as 1e-8
• Fixed stacking of images having fewer rows than threads (#1993), which processed uninitialized blocks
• Fixed cosmetic correction in calibration and live stacking (#2009): the hot and cold sigma values of the Calibration tab are now used, instead of those of the Cosmetic Correction dialog
• Fixed live stacking of 8-bit images (#1940): stacking no longer aborts at the third image with “input images have different precision”
• Fixed a crash in live stacking with shift-only registration, the default of the start_ls command

Files and formats #

• Fixed opening JPEG XL files wrapped in an ISO/IEC 18181-2 container (#1961)
• Fixed FITS extension truncation (#1984): extensions such as .fit. produced corrupted filenames like foo.fit..fit..fz; invalid extensions are now rejected
• Fixed XISF files storing their Bayer pattern only as native XISF metadata (!1102): files with no BAYERPAT keyword were not recognized as CFA images
• Fixed MIPS-FHI not being saved in 32-bit FITS files, so their display cutoffs were lost on reopening
• Fixed a crash when converting files in parallel (#2003) with a cfitsio library built without thread safety
• Fixed a crash when exporting a monochrome sequence as MP4 (#1992)
• Fixed a crash in channel extraction (#1973) when only some of the channels were extracted

Astrometry and photometry #

• Fixed an invalid EQUINOX value written in the FITS header (#1979) when the astrometric solution came from a solver that does not write an EQUINOX card
• Fixed an invalid local Gaia catalogue terminating Siril during plate solving: the file is now reported as unusable instead
• Fixed constellation names in annotations (#1955): names containing the Latin spelling of a Greek letter, such as Centaurus or Ophiuchus, were mangled
• Fixed AAVSO export writing V-C instead of the standardized magnitude when Cstd was left at its default of 0: Cstd is now mandatory, and empty text fields and an unknown airmass are written as “na” as the format requires

Display and interface #

• Fixed posterized on-screen rendering with a linear sRGB color management profile (#1948)
• Fixed a selection dragged past the right or bottom edge of the image (#1996) losing its last column and row, which made the crop one pixel smaller than expected
• Fixed the 100% zoom button (#1997) jumping to the top-left corner of the image instead of keeping the current view center
• Fixed the display sliders not being reset to 0–65535 (#2002) when switching to linear display while a stretch tool is open
• Fixed garbage characters in the save dialog file name (#1980) when a sequence is loaded and the displayed image is not one of its frames

Commands and Python scripting #

• Fixed a crash when the wavelet or linear_match commands were called with too few arguments (#1998)
• Fixed the cancel command sent through pipes (#2000), which now stops the running command
• Fixed a Python-related thread contention bug (#1959)
• Fixed a race in the Python virtual environment initialisation (#1977): pyscript could launch Python before the environment variables of the virtual environment had been exported
• Fixed set_image_pixeldata() in sirilpy (#1970): writing back float32 data to an image loaded as 16-bit no longer inflates its values by a factor of 65535

Build #

• Fixed compilation with OpenCV 5 and later

Translations #

The Japanese, Russian and Traditional Chinese translations have been updated. Thanks to all our translators! As a reminder, anyone can help translate Siril through Weblate , and no programming knowledge is required.

Upgrading to 1.4.5 #

We recommend all users of Siril 1.4.x to upgrade to version 1.4.5. The upgrade is fully compatible with your existing Siril configuration and data. Note that the macOS packages require macOS Ventura 13 or later.

This release is particularly beneficial if you:

• Stack with the GESDT rejection algorithm
• Use live stacking, in particular with 8-bit images or with cosmetic correction
• Work with JPEG XL, XISF or compressed FITS files
• Export photometry results to AAVSO
• Use a linear sRGB color management profile for display
• Write Python scripts or drive Siril through pipes

Looking ahead #

Development of Siril 1.5 continues on the master branch. For those seeking stability with the latest fixes, the 1.4 branch remains the recommended option.

Acknowledgments #

We thank everyone who reported issues and contributed feedback following the 1.4.4 release, as well as our translators who help bring Siril to a wider audience. Special thanks to our developers and testers who worked to address these issues quickly.

Siril is the work of many hands. Here are all the people who have contributed code to Siril over the years, each name sized by its number of commits:

Thank you all, and happy image processing with Siril 1.4.5!

Report bugs #

If you encounter problems with Siril 1.4.5, please report them via the Siril GitLab site . For bugs encountered with scripts, it’s here .

Your feedback is essential to help us maintain and improve Siril!