Astro Contrast Enhancer!
A New FREE PixInsight Script!
Astro Contrast Enhancer is a PixInsight tool I built for late-stage astrophotography image refinement. The goal is to provide an intuitive, real-time way to enhance fine structure, open up midtone depth, and lift broad veils of haze without turning the image into an overprocessed mess.
I have long wanted something in PixInsight that felt more like the best parts of Photoshop’s Texture, Clarity, and Dehaze controls, but adapted to the realities of deep-sky image processing. PixInsight has many powerful contrast tools, but they often require more setup, more masking, and more trial-and-error than I want when I am trying to polish an image late in the workflow.
ACE is built around three primary enhancement controls: Texture for fine detail and crisp structure, Clarity for midtone depth and dimensionality, and Dehaze for broad veil, contrast, and color-depth recovery. The controls are designed to work interactively so adjustments can be judged visually before committing them to the target image.
The tool also includes background protection, star protection, local selection tools, feathered edits, mask output, preview modes, before/after comparison, and undo/redo support. The intent is not to replace careful image processing, but to make a very common late-stage task faster, more focused, and easier to control.
What to know before using the tool
Astro Contrast Enhancer includes built-in FAQ, Display, Technical Appendix, and About buttons in the upper-right area of the app. Those sections provide more detailed guidance on workflow, screen sizing, protection behavior, local editing, preview limitations, and the underlying processing model.
Start with a stretched image
ACE is intended for images that have already been calibrated, integrated, color-balanced, and stretched. It is not a calibration tool, background extraction tool, deconvolution tool, or replacement for the core PixInsight workflow.
Think late-stage enhancement
This tool is best used after the image already has a reasonable global look. It is for controlled refinement: strengthening structure, opening midtone depth, reducing a flat or veiled appearance, and adding dimensionality without pushing the image too far.
Texture, Clarity, and Dehaze are different
Texture works on fine structure. Clarity targets mid-scale depth and dimensionality. Dehaze works on broader veiling contrast and color depth. Use them independently rather than treating them as three versions of the same slider.
Use small moves first
These controls can produce strong changes quickly. Start with modest adjustments, use before/after comparison often, and watch for dark halos, crunchy detail, harsh stars, or background roughness.
Protection matters
Background protection and star protection are central to the tool. They help keep the adjustment focused on useful structure while reducing the risk of damaging neutral sky, creating harsh stars, or amplifying noise in smooth areas.
Local edits are for targeted work
Use the local selection tools when the image needs different treatment in different regions. Feathered local edits can help strengthen a nebula, galaxy arm, dust lane, or problem area without forcing the same adjustment across the full image.
The preview is guidance
ACE uses a preview workflow for speed. The preview is meant to guide decisions interactively, while the final apply/save operation is rendered back to the PixInsight image at full resolution.
One supported window layout
ACE uses one supported interface layout. The window can be enlarged and saved, but the app does not include separate Standard, Compact, or Small-Screen layouts. On high-DPI Windows laptops, display scaling may reduce the usable workspace even when the physical screen resolution is high.
Applying your result
When adjustments are complete, use Apply to Target to write the result back to the active PixInsight image, or use Save New Image to create a separate processed image. ACE is designed to let you judge the preview first, then commit the final result when you are satisfied.
Pixinsight Script:
This PixInsight Script has just gone into Beta!
Would you like to try it out? I am looking for people who could use it and provide feedback and bug reports so that the tool can be fine-tuned.
New Version:
v0.9.7.11-Beta released 6-21-26!
This version introduced “Compact” mode, which operates with a smaller footprint and supports smaller screens.
Note:
Astro Contrast Enhancer v0.9.7.7-beta requires PixInsight 1.9.4 or newer.
This release has been updated for PixInsight’s new V8 JavaScript runtime, which is required by the native Apple Silicon / ARM64 build of PixInsight 1.9.4. It has also been tested on the Windows release of PixInsight 1.9.4.
If you are using an older version of PixInsight, please update PixInsight before installing or running Astro Color Mixer from the repository.
To Try it Out:
In PixInsight, go to Resources->update->manage repositories.
Add the repository: https://cosgrovescosmos.github.io/astro-color-mixer-pixinsight/updates/
Do an Update.
Exit PixInsight, and the installation will be done.
You may be asked to add an “UNSIGNED Repository”. That's because this is a beta, and I have not yet applied to PixInsight for a developer ID. Go ahead and say "yes" so the script loads.
Look for it under Scripts→CosgrovesCosmos→Astro Color Mixer.
Installation note:
After installing from the PixInsight repository and restarting PixInsight, Astro Color Mixer should appear in the Script menu.
Expected location: Script → Cosgrove’s Cosmos → Astro Contrast Enhancer
If the files install but the script does not appear in the Script menu, PixInsight may not have refreshed its feature-script index. This has been seen occasionally with third-party scripts.
To fix it:
If it does not appear, use:
Script > Feature Scripts > Add
Then select:
[PixInsight]/src/scripts/CosgrovesCosmos
After that, run:
Script > Feature Scripts > Regenerate
Click OK/Done.
If the script still does not appear, please send the following to contact@cosgrovescosmos.com:
- PixInsight version
- operating system
- whether the repository update reported success
- whether the script files appear to be installed
- whether Feature Scripts → Regenerate finds the script
- screenshot of the Feature Scripts window if possible