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