Install Cosmic Photons Tools in PixInsight
A quick setup guide for ImageBlend, NarrowbandNormalization, and ColourMask: Cosmic Photons tools for image blending, narrowband color balancing, and selective color masks.
Sources reviewed October 25, 2026
Before you start
Start with PixInsight installed and updated. This guide targets PixInsight 1.9.4 and later. Save any open work before installing updates, and keep an internet connection available for the downloads.
Cosmic Photons tools are provided free by Mike Cranfield and collaborators. Each tool has its own update repository: an address that tells PixInsight where to find its installation package and future updates. Add the three individual addresses below, rather than the Cosmic Photons home page.
1. Get to know the three tools
ImageBlend blends images together, including combining stretched luminance and RGB color. Repository: https://www.cosmicphotons.com/pi-scripts/imageblend/
NarrowbandNormalization balances the color channels in narrowband images, including SHO palettes. Repository: https://www.cosmicphotons.com/pi-modules/narrowbandnormalization/
ColourMask creates masks that select colors for targeted adjustments. Repository: https://www.cosmicphotons.com/pi-modules/colourmask/
Copy each complete repository address, including https:// and the final slash. ColourMask is the process spelling. The older ColorMask script repository is for PixInsight 1.9.3 and earlier; the publisher directs 1.9.4 and later users to the ColourMask process.
2. Add the repository addresses
You only need to add each address once. Leave your existing repositories in place.
- In PixInsight, open Resources → Updates → Manage Repositories. Menu wording may vary slightly with your version.
- Click Add. Paste the ImageBlend repository address from the previous section into the repository URL field, then confirm the dialog.
- Repeat Add for NarrowbandNormalization and ColourMask, using a separate entry for each address.
- Check that all three addresses are listed correctly, without spaces or duplicate entries. Click OK to save the repository list.
3. Download, close, and reopen
Adding a repository saves its address; checking for updates downloads the packages.
- Open Resources → Updates → Check for Updates. Let PixInsight read the repositories.
- Review the available packages for the three tools and apply the updates. Allow the downloads to finish.
- Close PixInsight normally. Accept the installation prompt if one appears, and allow the updater to finish. Reopen PixInsight if it does not restart automatically.
- Check for updates again and complete any remaining update cycle before opening the tools.
4. Find and check each tool
ImageBlend: open Script → Utilities → ImageBlend (the menu may be labeled Scripts). This is a script, so it is found in the Script menu.
NarrowbandNormalization: open Process → ColorCalibration → NarrowbandNormalization. You can also look under Process → All Processes.
ColourMask: open Process → MaskGeneration → ColourMask, or find it under All Processes. It is a process, so do not look for this version in the Script menu.
Open each interface and its built-in documentation to confirm it loads. You do not need to apply it to an image to complete installation. When ready to follow a workflow, use a duplicate image and check its input requirements first. Installing these tools does not require Gaia or MARS database paths.
Quick fixes if a tool is missing
No package offered: check the individual repository address for typing errors and confirm that you saved it. A tool that is already up to date may not appear in the update list; check its menu location before trying to install it again.
Downloaded but missing from the menu: finish the close-and-reopen installation cycle. Look in Script for ImageBlend and Process for the other two tools.
An old ColorMask script fails: use the ColourMask process repository above for PixInsight 1.9.4 and later. Read the publisher’s compatibility notes before trying legacy scripts.
Connection, package, or compatibility error: copy the exact error, record your PixInsight version and operating system, and compare your setup with the publisher’s current instructions. Avoid repeatedly adding the same repository or manually copying files into the application folder.
Once all three interfaces open, setup is complete. Use the settings in the relevant StellarPix processing tutorial for your image; installation alone does not choose processing settings. When sharing results, credit the tools and their authors as requested by Cosmic Photons.