Astro Contrast Enhancer!

  • A Free PixInsight Script -

Cosgrove's Cosmos Software • Free PixInsight Script

Reveal detail. Open depth. Lift the veil. ACE brings interactive Texture, Clarity, Dehaze, and protected local editing into one astrophotography-focused PixInsight workflow.

Texture Clarity Dehaze Local Editing Real-Time Preview Requires PixInsight 1.9.4
Get Started Introduction Video Coming Soon Image Science Article

Built for my own late-stage astrophotography workflow and freely shared in the hope that others may find it useful in theirs.

Astro Contrast Enhancer hero image showing the software and its contrast-enhancement purpose
ACE Interface Screenshot Replace ACE_HERO_IMAGE_URL with the final interface screenshot, then change data-placeholder to false.
Astro Contrast Enhancer — Texture, Clarity, Dehaze, and protected local editing
Why I Built It

Keep the Final Contrast Work Inside PixInsight

ACE grew from a repeated interruption in my own processing: leaving PixInsight for one final round of Texture, Clarity, and Dehaze adjustments in Photoshop.

PixInsight already contains many excellent contrast tools. What I wanted was something different: an intuitive, real-time environment for the final refinements that help an image reveal more structure, depth, and visual presence.

Astro Contrast Enhancer brings those adjustments together in one focused script designed around stretched astrophotography images. It is not intended to replace PixInsight's established processes or Photoshop. It is simply the approach I developed to make a common finishing step faster and more direct.

I can explore an adjustment, compare it immediately with the original, protect stars and backgrounds, apply it globally or locally, and commit the full-resolution result without leaving PixInsight.

A Simpler Finishing Workflow

Stretched Image
ACE

Explore contrast refinements, compare the result, and apply it directly to the PixInsight image.

The Complete Workspace

See ACE as You Will Actually Use It

ACE brings real-time preview, Texture, Clarity, Dehaze, protected local editing, star and background protection, comparison, and full-resolution output together in one focused PixInsight interface.

Full Astro Contrast Enhancer interface showing the image preview, Texture, Clarity, Dehaze, local editing, and protection controls
The complete ACE interface. Select the image to open the full-resolution screenshot.
1 Real-Time Image Preview
2 Texture, Clarity, and Dehaze
3 Protected Local Editing
4 Star and Background Protection
5 Before/After Comparison and Apply

The numbered guide identifies the major capabilities without covering or reducing the readability of the actual interface.

Meet ACE

Three Controls for Three Different Visual Problems

Texture, Clarity, and Dehaze are not three strengths of the same contrast operation. Each addresses a different way an image can feel visually incomplete.

Texture

Fine Structure

Enhances small-scale structure such as filaments, dust boundaries, folds, and delicate detail without behaving like conventional sharpening.

Clarity

Perceived Depth

Shapes broader tonal relationships so structures feel more open, layered, and dimensional while preserving smooth transitions.

Dehaze

Broad Veiling

Reduces the impression of a broad veil across the image, improving large-scale separation while allowing contrast and color depth to emerge together.

Use them independently or together. The goal is not to maximize every control, but to choose the treatment that best addresses what the image needs.
See ACE in Action

The Difference Should Be Visible, Not Merely Described

Drag each divider to compare the original with the ACE result. The left side is the original image; the right side shows the ACE treatment.

Demonstration note: Some of these examples are intentionally pushed farther than many astrophotographers would choose for a finished image so that the character of each control is easy to see on the page. In normal use, the astrophotographer decides how subtle or strong the treatment should be. ACE provides the range and the protections; it does not decide the preferred result.
Fine Structure

Texture Example

Use a detailed nebula or galaxy crop where small structure becomes easier to recognize.

After ACE Texture
Before ACE Texture
Before TextureOriginal image
After TextureACE result
‹›
Before After

Look for improved filament, fold, and boundary definition without obvious halos or brittle detail.

Object: Placeholder Texture: TBD Scale: TBD
Tonal Depth

Clarity Example

Use a galaxy or dusty nebula where broad layers become more open and dimensional.

After ACE Clarity
Before ACE Clarity
Before ClarityOriginal image
After ClarityACE result
‹›
Before After

Look for stronger separation among arms, dust, cores, and surrounding structure without harsh tonal plateaus.

Object: Placeholder Clarity: TBD Scale: TBD
Broad Veiling

Dehaze Example

Use an extended target where broad haze or flatness visibly obscures larger relationships.

After ACE Dehaze
Before ACE Dehaze
Before DehazeOriginal image
After DehazeACE result
‹›
Before After

Look for reduced veiling, clearer broad-scale separation, and stronger apparent color without damaged highlights.

Object: Placeholder Dehaze: TBD Scale: TBD
Complete Treatment

Combined ACE Example

Use a full image that benefits from a restrained combination of all three controls.

After combined ACE processing
Before combined ACE processing
Before Combined ACEOriginal image
After Combined ACEACE result
‹›
Before After

Look for balanced improvement in fine structure, depth, and broad openness rather than one uniformly stronger effect.

Object: Placeholder Texture: TBD Clarity: TBD Dehaze: TBD
Protected Local Editing

Apply the Effect Where the Image Needs It

Not every region benefits from the same adjustment. ACE includes a local-editing workflow that makes the selected region, its protected surroundings, and the feathered transition visible before the adjustment is committed.

ACE lasso selection with the protected grid visible
Lasso and Protected Grid Replace https://images.squarespace-cdn.com/content/v1/60d7296aaa6c862de19a7d3b/8b9deec4-a549-4c2b-bf52-1c9e65f6b963/lasso-only.jpg?format=2500w with a screenshot showing the selected lasso and the protected grid outside it, then change data-placeholder to false.
The lasso identifies the editable region while the grid makes the protected area immediately visible.
ACE lasso selection with feathering visible
Lasso with Feathering Screenshot showing the transition area around the selected region.
Feathering blends the local adjustment into the surrounding image rather than creating a hard-edged edit.
Draw and Adjust a Lasso Define the target region visually, reposition it, and refine the selection before committing the edit.
See What Is Protected The protected-grid overlay makes it clear which pixels will remain outside the local treatment.
Feather the Selection Blend the adjustment gradually into the surrounding image so the local treatment does not create a visible hard boundary.
Protect Stars and Background Built-in protections help reduce harsh stars, damaged neutral sky, and unnecessary amplification of smooth noise.
Getting Started

Install ACE Through the Cosgrove's Cosmos Repository

ACE is installed through PixInsight's repository system. The update URL is entered inside PixInsight; it is not intended to be opened as a web page.

PixInsight 1.9.4 is required. ACE depends on capabilities introduced in PixInsight 1.9.4 and is not supported on earlier releases. Update PixInsight before installing ACE.

Repository Installation

Existing Astro Color Mixer users may already have this repository installed. In that case, run a normal PixInsight update and restart the application.

In PixInsight 1.9.4, go to Resources → Updates → Manage Repositories.

Add the Cosgrove's Cosmos update repository: https://cosgrovescosmos.github.io/astro-color-mixer-pixinsight/updates/

Run Resources → Updates → Check for Updates and complete the update.

Exit PixInsight. The installation is completed as PixInsight closes and processes the update.

Restart PixInsight and look for ACE under Script → CosgrovesCosmos → Astro Contrast Enhancer .

You may be asked to allow an “UNSIGNED Repository.” ACE is currently being distributed as beta software, and I have not yet applied to PixInsight for a developer ID. Choose Yes so the repository update and script can load.
Frequently Asked Questions

What to Know Before You Begin

Which version of PixInsight is required?

Astro Contrast Enhancer requires PixInsight 1.9.4. Earlier versions are not supported, so update PixInsight before installing or running ACE.

What kind of image should I use with ACE?

ACE is designed primarily for images that have already been calibrated, integrated, color balanced, and stretched. It is a late-stage refinement tool rather than a replacement for the core PixInsight workflow.

Do I need to use Texture, Clarity, and Dehaze together?

No. Each control addresses a different visual problem. Use only the control or combination that helps the image.

Does ACE replace sharpening or other PixInsight contrast tools?

No. ACE complements deconvolution, multiscale processing, LocalHistogramEqualization, HDR methods, and other established tools.

Should I use ACE on a starless image?

ACE can be used with stars present, and star protection is included. Starless processing may still make aggressive structure work easier on some images, but it is not required.

Is the preview the final full-resolution result?

The preview is optimized for responsive visual evaluation. When you apply the result, ACE replays the selected adjustments against the full-resolution PixInsight image.

Why can the controls be pushed beyond a reasonable result?

I often evaluate an adjustment by moving from too little to too much and then returning to the useful balance. ACE includes safeguards but leaves the final judgment with the astrophotographer.

What should I do if the ACE window does not fit my screen?

ACE uses one supported compact interface. On high-DPI Windows laptops, temporarily reducing operating-system display scaling toward 100% may be necessary.

Where can I send feedback or report a problem?

Send feedback and bug reports to contact@cosgrovescosmos.com. Include your PixInsight version, operating system, and enough detail to reproduce the issue.

Learning Center Article

Curious About the Image Science Behind ACE?

A separate in-depth article tells the development story: the Photoshop inspiration, the early assumption that the three controls differed mainly by scale, why that approach failed, and how Texture, Clarity, and Dehaze evolved into three different image models.

Understanding Astro Contrast Enhancer

Astro Contrast Enhancer is freely shared software developed for my own astrophotography workflow. Experiment, compare, and adapt the approach to the needs of your own images.