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
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
Nigel A Ball, Fellow of Royal Astronomical Society (FRAS), Sept 2025
I've been using your NSG PlugIn for PixInsight for just over a month now.
What a fantastic piece of software!!!
Very intuitive and your YouTube videos were very helpful in getting me up and running.
I'm not one for superlatives but NSG has really revolutionized my processing.
Living in a Bortle 5 location between two towns I really did struggle with gradient removal.
I've also discovered that Moon gradients can be corrected by using a Reference Frame from a Moonless night.
Thank you again and clear skies!
Xu Kang, May 2025
... Your dedication to advancing astrophotography post-processing deserves sincere appreciation.
I look forward to pushing the boundaries of imaging with these sophisticated algorithms.
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, Adam Block, 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.
I specialize in providing software solutions for astronomy enthusiasts.