Update October, 2023: The EZ Processing Suite is no longer available in PixInsight

PixInsight is powerful post-processing software that allows you to apply advanced processes to your images to produce an excellent result.

One of the things imagers struggle with is noise: the fine, grainy noise that occurs due to having few exposures or short exposures.

PixInsight is a powerful software that offers a wide range of noise reduction techniques, including MultiscaleLinearTransform, TGVDenoise, and MultiscaleMedianTransform.

These processes offer many settings and options, which can be overwhelming for users trying to find the best settings for their specific images. Experimentation is important in PixInsight, but it can be challenging to make informed choices about settings when it’s unclear what effect they will have on your images. Overall, finding the right settings to effectively reduce noise in your images can be a complex and time-consuming process in PixInsight.

Update December 2022: There’s a better way to reduce noise, using NoiseXTerminator, an AI-based and paid process that reduces noise in your images; a free trial is available and there’s a tutorial here.

While you can certainly learn how to use the noise reduction processes effectively, there is an easier option: a set of scripts that make things like noise reduction a matter of making a couple of selections (or sometimes none at all) and executing the script. The scripts I’m referring to here are the EZ Processing Suite for PixInsight.

The EZ Processing Suite is a set of six scripts that perform functions like denoising, deconvolving and other processes. The suite of scripts breaks down complex processes into a few easy steps and selections, and you can often use the default settings for excellent results.

Result Of Using EZ Denoise To Reduce Noise

Update October, 2023: The EZ Processing Suite is no longer available in PixInsight

The EZ Denoise script is based on lots of experimentation and it produces excellent results at its default settings. For example, this is a zoomed-in view of a noisy image:

And this is the same area of the image after applying EZ Denoise using the default settings:

The difference is dramatic, and you can achieve this type of result with very little effort by simply using the default settings and waiting for the script to execute.

Installing the EZ Processing Suite

Update October, 2023: The EZ Processing Suite is no longer available in PixInsight

Installing the EZ Processing Suite is completely automatic.

1. Start PixInsight and select from the menu Resources – Updates – Manage Repositories.

2. Click the Add button and paste the following URL in the box:

https://darkarchon.internet-box.ch:8443/

3. Click Ok to close the window.

4. From the menu, select Resources – Updates – Check for Updates and allow the process to complete.

5. Exit PixInsight (save your work first) and allow it to apply updates.

When you restart PixInsight, you should see the EZ Processing Suite under the Script menu.

Using EZ Denoise To Reduce Noise

Your image should be in its unstretched linear state and, for best results, it is recommended that you first run either AutomaticBackgroundExtractor or DynamicBackgroundExtraction. Noise reduction is usually done on a luminance image only, however, you can also use EZ Denoise with color images and you might get a better overall result if you denoise your color image as well. As always, experimentation is key.

Using EZ Denoise is as simple as it sounds: just open your image and from the menu, select Scripts – EZ Processing Suite – EZ Denoise.

Update October, 2023: The EZ Processing Suite is no longer available in PixInsight

When you start the script, it warns you that you could lose your unfinished images, so it is recommended that you save your work before you use the script.

Once the EZ Denoise window is on your screen, select the image you wish to denoise where it says ‘<No View Selected>’.

EZ Denoise displays your image on the right side of the screen and the settings that it will use on the left side of the screen. If your image is completely black or very dark, click the checkbox at the upper-right of the window labeled ‘Alternate view of image’.

Click the button labeled ‘Evaluate EZ Denoise Run’ and wait for the process to finish. Once the process completes, you’ll see a second tab above your image and it will be selected, as shown:

This selected tab, labeled ‘Denoise Run 1’, is what your image looks like after executing the denoise processes. You can use the magnifying glass icons above your image to zoom in and you can use the scroll bars to pan around your image.

You can flip back and forth between your original image and the denoised image and the screen position and zoom level will be the same between the images, making it easy to compare the results.

Generally, EZ Denoise does a very good job and you won’t have to modify any settings. If you’re happy with the result, click the button labeled ‘Run with these settings’ on the right side of the window.

If you’re not satisfied with the result, you can change key setting used by the TGVDenoise and MMT processes. Review the mouseovers for details about what each setting does. Once you change settings, click ‘Evaluate EZ Denoise Run’ and once it completes, you’ll see another selected tab that shows what your image looks like now. You can flip between tabs to compare the original and results of each run.

The other buttons on EZ Denoise allow you to create the masks only and allow you to create the masks and process icons in case you want to apply the denoise process yourself.

If you change any settings in EZ Denoise, you can reset them by clicking the respective Reset button on each of the TGV and MMT settings tabs.

Once the script exits and closes its window, you’ll see three new windows on your PixInsight desktop. These are the masks EZ Denoise used while processing your image and you can safely discard these, or you can reuse them for some other purpose.

EZ Denoise makes it easy to achieve excellent results, even at default settings.

Learn More About Astro Image Processing Using PixInsight

I have a page dedicated to a PixInsight broadband/LRGB and narrowband workflow, and my blog has a whole section dedicated to processing images using PixInsight. Also, consider downloading my free eBook about remote imaging using Slooh.com, a great way to boost the number of nights you can spend observing…Remote Astrophotography Using Slooh.com!

Conclusion

In this article, you learned about effective nose reduction using the EZ Denoise script which is part of the EZ Processing Suite of scripts. I explained how to install the scripts and explained how to use the EZ Denoise script.

More Articles In This Series

This article is part of a whole series of articles about processing images using PixInsight. Get the index article here, which explains an entire workflow for processing an image using PixInsight along with several useful scripts that make processing a lot easier than processing manually.

Update December 2022: There’s a better way to reduce noise, using NoiseXTerminator, an AI-based and paid process that reduces noise in your images; a free trial is available and there’s a tutorial here.