Which process for linear noise reduction

[javajunkie2121]

Hi: 

I've had some luck with a light touch of ATWT in the past for linear state noise reduction.

I see MLT and MMT and I'm wondering what folks use for linear state noise reduction?  MLT or MMT?  Both?  I'm trying to experiment with these processes.

jeff

[Alejandro Tombolini]

Hi Jeff,

See this post that can be helpful.

Saludos, Alejandro.

[javajunkie2121]

Hi Alejandro:

Thanks for the reply.

I saw that post by Juan, and particularly this comment:

MLT can be more difficult to control than MMT in this sense, mainly because MMT is much better at isolating structures. However, MLT can be better to reduce heavy background noise.

so I was wondering if folks choose one or the other, or both?

jeff

[Alejandro Tombolini]

I use both but in general I have more "affinity" with MLT.
If the image is a difficult target for noise reduction I recommend that you make previews and you try the different noise reduction tools to compare.

Saludos, Alejandro

[jkmorse]

The key for MLT, at least for me, is to get the mask right.  Be sure to run the mask preview and adjust the amplification until you are protecting the target and leaving the background white.  If you get that right, I find MLT to be both intuitive and powerful.

Best,

Jim

[jerryyyyy]

Hi, I found that you have to make sure the mask you create starts with a stretched image.  This may be obvious, but I say it since I only realized that after it was also said explicitly in a tutorial. 

Interesting discussion of the different procedures, once you have the mask.  Where I find trouble is on the edges of the DSO... either the mask covers too little or too much but this is hard to see just looking at the mask....

I have read you should noise reduce in both linear and non-linear phases, but to me it is sure a lot easier in the non-linear phase.  Is there an advantage to doing it in linear where the risks of screwing up are greater. 

Lifetime learning going on here. 

[jkmorse]

Jerrry,

I was like you and rarely did noise reduction in linear phase but the results with MLT are so clean it's amazing.  One comment also, I have had no trouble building my MLT mask on the unstretched image, just need to get the amplification right.  From a personal perspective I would rather over protect those edges than over process though again, I am always testing with MLT which is one of my favorite tools in the whole PI toolbox.

Best,

Jim

[msmythers]

I'm with Jim on the use of MLT. It sometimes is the only noise reduction needed for some of my images. One thing for those new to PixInsight and the use of MLT. Remember to reset STF before you preview your Linear Mask in MLT. Otherwise you will not be able to set the correct Amplification.



Mike