StarXTerminator is an AI-powered tool to remove stars from astronomical photographs. This allows separate processing of stars and background objects, or simply leaving out the stars altogether. It is available for PixInsight and Photoshop. The photoshop version also works with Affinity Photo.

StarXTerminator uses an advanced convolutional neural network with a unique architecture suited to this task. This network has been extensively trained on photographs from a wide range of instruments, from camera lenses to the James Webb space telescope. Small stars, big stars, huge stars, and even diffraction spikes are recognized and removed, with minimal impact to non-stellar features.

StarXTerminator is very easy to use, with no sliders to tweak or parameters to adjust. Check out the StarXTerminator usage notes for tips on how to best apply it to your images.

System Requirements

✅  PixInsight
✅  Photoshop
✅  Affinity Photo

StarXTerminator is available as a plug-in process module for PixInsight and Photoshop. The photoshop version also works with Affinity Photo.

StarXTerminator requires a computer with a modern CPU having “AVX” instructions required to run neural networks. Older CPUs, and even some modern stripped-down CPUs in mini-PCs and lightweight laptops lack AVX instructions and are not supported. Request a trial before purchasing to make sure StarXTerminator will work on your machine.

Neural network computations can benefit greatly from GPU acceleration. On Macs, GPU acceleration of StarXTerminator is automatic, leveraging the “CoreML” software library provided by Apple. Performance is particularly fast on recent Apple silicon based Macs (M1, M2, etc.) due to their extremely performant built-in GPU and neural engine hardware.

On Windows and Linux machines, GPU acceleration takes a bit more effort.

Additional requirements:

PixInsight 1.8.9-1 or later, or
Photoshop CS4 or later (64-bit only), or
Affinity Photo 1.0 or later
MacOS 11 (Big Sur) or later
- GPU/Neural Engine recommended for fast performance, but not required. External GPUs are not supported.
- Apple silicon neural engines and GPUs (e.g., M1, M2) are supported natively
Windows 10 or later
- Modern CPU capable of running neural networks (AVX, SSE instruction set extensions)
Linux (PixInsight only)
- Ubuntu 18.04 or later, or equivalent (glibc 2.27 or later required)

Revision History

PixInsight Module
Version	Date	Comments
2.2.1	8 Sep 2023	MacOS only: fixed an issue that caused a memory leak during large batch processing tasks.
2.2.0	4 Sep 2023	Corrected how StarXTerminator handles masks: protected features no longer appear in the stars-only image. Added a mask selection option in the Process Batch function to allow a mask to be applied to all images in a batch.
2.1.4	19 Aug 2023	Fixed bugs causing crashes and incorrect results on certain images. More intelligent validation/selection of AI definition files.
2.1.3	7 Aug 2023	Compatibility updates for PixInsight 1.8.9-2. New tiling algorithm to better handle the edges of images. Internal processing is now 64-bit floating point for maximum precision. MacOS-specific updates to enable 32-bit floating point neural network computations (requires MacOS 12 or later). Adjusted normalization algorithm to avoid histogram clipping in shadow regions. Fixed a Windows-specific issue causing a ghost border around minimized (iconified) process window. Updated process icon.
2.0.5	6 Oct 2022	Corrects a bug that could cause the user to have to re-enter their permanent license key unnecessarily.
2.0.3	30 Sep 2022	Adjusted Unscreen Stars function to avoid saturated pixels when one or more channels in the original image are clipped. Code-signed Windows and MacOS modules for better compatibility with anti-malware software.
2.0.2	15 Sep 2022	All-new AI11 neural network with greatly improved performance on a wider range of images, trained on images including data from the James Webb and Hubble space telescopes. Automatic handling of linear and nonlinear images.
1.3.1	12 Jul 2022	Added batch processing function to save starless and stars images generated from a collection of input images.
1.2.0	8 Jan 2022	Fixes an issue that prevented the “stars” and “linear” parameters from working correctly in scripts and ImageContainers. The stars-only image now inherits the FITS parameters and astrometric solution of the original image. MacOS: fixed a memory leak.
1.1.0	8 Nov 2021	Necessary for compatibility with AI version 6. Uses PixInsight’s update repository system for installation. AI files are now installed as part of this process.
1.0.0	8 Oct 2021	Initial release

Photoshop Plug-in
Version	Date	Comments
2.0.6	25 Nov 2022	Updated the MacOS and Windows installers to add installation for Affinity Photo 2. No changes to the plugin.
2.0.6	1 Nov 2022	Corrects a bug that could cause failure during license key entry when also running NoiseXTerminator.
2.0.5	6 Oct 2022	Corrects a bug that could cause the user to have to re-enter their permanent license key unnecessarily.
2.0.4	1 Oct 2022	Fixed large-overlap mode in Windows version. Added processing progress indicator for Affinity Photo. Adjusted MacOS and Windows installers for compatibility with Mac App Store and Microsoft Store versions of Affinity Photo.
2.0.2	15 Sep 2022	All-new AI11 neural network with greatly improved performance on a wider range of images, trained on images including data from the James Webb and Hubble space telescopes.
1.2.2	30 Sep 2021	Update for Windows version only: eliminates the need to move the three Microsoft DLL files to Photoshop’s or Affinity Photo’s application directory. These files can now be placed alongside of the plugin file itself (StarXTerminator.8bf).
1.2.1	27 Sep 2021	Update for Windows version only: reverts to running only on the CPU. GPU selection was found to be unreliable. This will be addressed in a future update.
1.2	26 Sep 2021	Supports processing of 8- and 16-bit RGB and grayscale photos. Windows version selects GPU if available. Removed batch size adjustment and calibration (unnecessary). Fixed compatibility with Affinity Photo for Mac.
1.1	18 Sep 2021	Adds native greyscale image processing. Adds AI download for Mac version, and download progress indicators for Windows and Mac versions.
1.0	12 Sep 2021	Initial release

AI Definition
Version	Date	Comments
11	15 Sep 2022	All-new neural network architecutre trained from scratch on a much wider data set, including data from the James Webb and Hubble space telescopes. Greatly improved retention of non-stellar detail, especially from the glare of very bright stars. Revamped noise matching engine that fills in noise where the stars once were that closely matches the rest of the image.
10	18 Apr 2022	Corrects a malfunction in the noise matching module that could cause black or white squares around the edges of uncropped images or in clipped regions of images. Same core neural network and training as AI8.
9	9 Apr 2022	Corrects a malfunction in the noise matching module that could cause black or white squares around the edges of uncropped images. Same core neural network and training as AI8.
8	18 Mar 2022	Re-trained from scratch for greater precision in removing stars and retaining non-stellar details. Training data set further expanded to include tough cases such as bright stars, crowded star fields, and especially galaxies and galaxy clusters. Particular attention given to retaining galaxy disk details such as H-II regions. Also includes an improved statistical noise matching engine that matches the noise statistics of surrounding areas when removing large stars, making these areas blend into the rest of the image.
7	16 Dec 2021	Revamped neural network architecture giving greater accuracy of star removal and better retention of non-stellar structures. Trained on an expanded data set that includes more galaxy images, resulting in better retention of galaxy cores and non-stellar details in spiral arms. AI7 retains much more detail around stars than AI5, largely correcting the overly-smooth areas of that version.
6	8 Nov 2021	Only available for PixInsight version at this time. Implements matching of noise statistics for replaced pixels, resulting in a more natural appearance and elimination of the “smooth” areas around stars seen in earlier AI versions.
5	26 Sep 2021	Improved handling of monochome narrowband and noisy nebula photos.
3	18 Sep 2021	Much better handling of wide-field (short focal length) galaxy images. Better handling of crowded fields of small stars from short focal length instruments. Better avoidance of small non-stellar features (e.g., small patches of nebulosity and background galaxies).
2	12 Sep 2021	Initial release