AstroProcessing - NSG & PMM

The highly acclaimed PixInsight scripts NormalizeScaleGradient and PhotometricMosaic are designed to help you get the most out of your astronomical images. I have included extensive reference documentation, with 'Quick Start' sections, for both scripts. To download and install these scripts within PixInsight, see the Repository page.

For the most accurate results from NSG, you need to Purchase NSGXnml. This C++ module also enables all NSG's extra capabilities.

About Me

Author: John Murphy I specialize in providing software solutions for astronomy enthusiasts.

I worked as a software engineer at HP, leaving in 2016 to persue my interests. These include Physics, Astronomy, and writing astronomical software.

Physics with Astrophysics BSc Degree, Birmingham University, UK

Video Tutorials

Official NormalizeScaleGradient YouTube videos:

AdamBlockStudios; Mosaics (PhotometricMosaic):

Customer Reviews (NSG & PMM)

Sky at Night magazine, October 2023, p78

Mathew Ludgate, Astronomy Photographer of the year shortlisted entrant in the 'Stars and Nebulae' category:

... After using the WBPP script in PixInsight to perform image calibration and registration, I utilised the Normalize Scale Gradient (NSG) script by John Murphy. This corrects the brightness and gradient of your subs using differential photometry to model the relative scales and gradients. I image at a dark site but I still find NSG very useful as a first step...

Assemble the mosaic
The next step is to combine the mosaic panels. I used the PhotometricMosaic script in PixInsight, which gives excellent results, with seamless blends between panels. To use it, you must first plate-solve all your mosaic panels images and then run the Mosaic by Coordinates script. Once the registered panels are created, I trimmed ~2 pixels from each edge using TrimMosaicTile and then ran PhotometricMosaic. I find the defaults tend to work well, but it's worth trying different combination modes to see which blends the panels most seamlessly...

Paul Denny, 2023

... thank you for writing this script [NSG] and making it available to the astrophotography community. I am quite new to this and still on a steep learning curve, but I do know enough to see what a great tool this is, as is your excellent documentation and YouTube videos. I feel as though I understand and have control over this part of the processing flow for the first time.

Cloudy Nights, Larry Phillips, 2023

I have been using PhotometricMosaic for quite some time with great success. I can't image anything working better since PMM, which in my experience, works perfectly.

AdamBlockStudios, 2022

... I helped (with some advice and ideas) the brilliant John Murphy as he crafted NormalizeScaleGradient (NSG). The normalization and weighting of data is a fundamental and critical component of image processing.