VeraLux Stretch
Wavelet Enhancement
Welcome
This tool takes a linear (unstretched) deep-sky image and applies a non-linear stretch to reveal faint nebulosity and galaxy structure while preserving star colour and keeping the background clean and neutral.
The goal is to bridge the gap between a raw stack and a visually pleasing result with minimal manual effort — the kind of image you might share or print, produced in seconds rather than hours of careful post-processing.
Getting started
- Prepare your image — plate-solve, remove gradients, and colour-calibrate in PixInsight (MGC, SPCC) or Siril (Background Extraction, PCC). Do not stretch.
- Load your XISF or FITS file, or pick a sample from the dropdown.
- The stretch is applied automatically. Adjust the sliders to taste.
- Optimize (optional) — fetches a survey reference image matching your field of view and orientation, then searches for stretch parameters that best reproduce the tonal distribution of a professional survey.
- Save the result as PNG.
Philosophy
Deep-sky stretching is inherently subjective. Rather than prescribe a single “correct” result, this tool gives you a strong starting point and lets you refine it. The optimizer targets histogram shape, not pixel values — your data’s character and colour balance are preserved even when matching a reference.
All processing runs entirely in your browser. No images are uploaded anywhere.