PixInsight's MureDenoise Script
This is a relatively new script and is designed to reduce fine-grained noise in a linear mono channel single sub-frame or stack of sub-frames. A more detailed and technical description is found here, PI forum MureDenoise topic.
I have begun to use this script on each calibrated, registered and integrated mono channel, ie an integrated stack of the Red data channel or the Blue channel. The script must be used on a mono channel before any channel combination (whether RGB or NB data combining) and also before DBE is applied. It can be carried out prior to any cropping.
I followed the tutorial on the PI forum and firstly measured the Gaussian Noise of my light frames using PI's DarkBiasNoiseEstimator script. This need to be done for each master dark eg 300s master, 600s master, 1200s master etc as the Gauusian Noise may have different values depending on the length of the dark frame. The Gain value was obtained from QSI's website from my ccd's technical specification.
The results for the Luminance integrated stack of my recent M96 and M105 is shown below:
Before running MureDenoise
After running MureDenoise
I am still experimenting gwith the settings of the script - using a Flatfield and varying the selected 'Interpolation method'. I will post an update here if (or when) I come to any conclusion on the optimum settings for my images.
Following the MureDenoise script I have then cropped the integrated stacks and followed my normal processing workflow, normally the next step being Dynamic Background Extraction. You may find that you need to adjust the settings of the Screen Transfer Function after applying the DBE process to avoid an over-enhanced STF screen stretch.
Importantly the non-linear stretched image is much smoother, having less fine-grained noise, which is the aim of the script. This new script is now an extablished step in my processing workflow.