The Unified Photometric Engine: HyperMetric Stretch & StarComposer.
Important
Original Authorship & Credits
This script is a port of the original VeraLux tools developed for Siril/Python by Riccardo Paterniti. All credit for the underlying mathematics, the "True Color" methodology, and the sensor weighting logic belongs to him.
- Original Project: VeraLux.space
- Original Author: Riccardo Paterniti
- License: GPL-3.0-or-later
This repository is maintained by lucasssvaz (GitHub: lucasssvaz).
The original JavaScript/PJSR port was created by killerciao (GitHub: killerciao). Thanks to Riccardo Paterniti for the original Python implementation and to killerciao for the original JavaScript/PJSR port.
This repository houses a PixInsight JavaScript Runtime (PJSR) implementation of the VeraLux ecosystem. It unifies two powerful engines into a single interface:
- HyperMetric Stretch (HMS): A physics-based linear-to-nonlinear stretcher (Ported from Python v1.3.1).
- StarComposer: A high-fidelity star reconstruction and composition engine (Ported from Python v1.0.2).
Real-time parameter visualization for both modules.
- Live Preview: See your stretch or composition results before processing with fast downsampled preview.
- Tab-Aware: Automatically adapts to show HyperMetric Stretch or StarComposer preview based on active tab.
- Multiple Scale Options: Choose from 1:1, 1:2, 1:4, 1:8, or Fit-to-Window for optimal preview speed.
- Interactive Navigation: Pan with mouse drag, zoom with mouse wheel, inspect pixel values on hover.
- Position Memory: Preview maintains your scroll position when refreshing parameters.
- Fast Iteration: Optimized downsampling means instant parameter adjustments at lower scales.
- Reset Buttons: Quick parameter reset for both HyperMetric Stretch and StarComposer modules.
Operates on the axiom that standard histogram transformations destroy photometric color ratios (hue shifts).
- Smart Iterative Solver: The "Auto-Calc" now simulates the entire post-stretch scaling pipeline. It detects black clipping ("Floating Sky Check") and iteratively adjusts the target to find the safest maximum contrast.
- Unified Color Strategy: A single, intuitive slider to balance the equation.
- Left (<0): Cleans noise by increasing Shadow Convergence.
- Right (>0): Softens highlights by relaxing Color Grip.
- Sensor-Aware: Expanded database including Seestar S50/S30, IMX585, and Narrowband (HOO/SHO) profiles.
- In-Place Editing: Processes directly on the active image without creating duplicates.
Decouples the star field from the main object to prevent bloating and bleaching.
- Star Surgery: Includes native tools for Large Structure Rejection (LSR) (removing galaxy cores from star masks) and Optical Healing (fixing chromatic aberration/halos).
- Vector Preservation: Stretches stars without losing their core color temperature.
- Auto-Stretch Stars: A specialized solver that ignores black backgrounds to find the optimal visibility for linear star masks.
- Composition Modes: Choose between Linear Add (Physical accuracy) or Screen (Safe blending to prevent core saturation).
- Open PixInsight.
- Go to Resources > Updates > Manage Repositories.
- Click Add and paste the URL:
https://raw.githubusercontent.com/lucasssvaz/VeraLuxPorting/main/dist/ - Click OK.
- Go to Resources > Updates > Check for Updates.
- Install the package and Restart PixInsight.
- Download the
.zipfile from the latest Release. - Extract
VeraLuxSuite.js. - Open PixInsight.
- Go to Script > Execute Script File...
- Select
VeraLuxSuite.js.
The right side of the interface shows a live preview of your processing:
- Scale Selection: Choose preview resolution (1:1, 1:2, 1:4, 1:8, or Fit) for speed vs quality.
- Navigation:
- Mouse wheel to zoom in/out
- Click and drag to pan around the image
- Hover over pixels to see RGB values
- Preview Refresh: Click to update the preview with current parameters (very fast at lower scales).
- Iterative Workflow: Adjust parameters → Preview Refresh → Tweak → Preview Refresh → Process when satisfied.
Use this for your main image (Linear).
- Prerequisites: Image must be Linear, Background Extracted, and Color Calibrated (SPCC).
- Mode: Select Ready-to-Use for the new Unified Strategy workflow.
- Sensor: Select your camera profile (or Rec.709).
- Solve: Click ⚡ Auto-Calc Log D. The solver will find the perfect stretch intensity.
- Preview & Refine:
- Click Preview Refresh to see the result.
- Use the Color Strategy slider to adjust.
- Background too noisy? Slide Left.
- Stars too hard/white? Slide Right.
- Click Preview Refresh after each adjustment.
- Process: Click PROCESS STRETCH when satisfied (modifies active image in-place).
- Reset: Click ⟲ Reset to restore default parameters.
Use this to recombine a Linear Starmask with a Stretched Starless image.
- Input: Select your Starmask (Linear) and Starless Base (Stretched) from the dropdowns.
- Calibrate: Click ⚡ Auto-Stretch Stars. This calculates the intensity needed to make linear stars visible.
- Preview & Surgery (Optional):
- Click Preview Refresh to see the initial composition.
- LSR: Increase if your star mask contains pieces of nebulosity or galaxy cores.
- Healing: Increase if your stars have purple/green halos.
- Click Preview Refresh after each adjustment.
- Process: Click PROCESS STAR COMPOSITION when satisfied (creates new image).
- Reset: Click ⟲ Reset to restore default StarComposer parameters.
This project is licensed under the GNU General Public License v3.0.
You are free to use, modify, and distribute this software under the terms of the GPLv3. Any derivative works must also be open-source and preserve the original copyright notices and attribution to the original authors.
Copyright (c) 2026 lucasssvaz (Maintained JavaScript/PJSR port)
Copyright (c) 2025 killerciao (Original JavaScript/PJSR port)
Copyright (c) 2025 Riccardo Paterniti (Original Python implementation)