PixInsight Forum (historical)

PixInsight => Tutorials and Processing Examples => Topic started by: alcol on 2016 September 02 12:23:45

Title: how to use the Linear Mask in MLT tool
Post by: alcol on 2016 September 02 12:23:45

Hi there

Can someone point me in the direction of information on how to use the Linear Mask in the MultiscaleLinearTramsform tool. I have tried and failed to get it to work. Probably very simple but I can't get it to work.

Thanks

Alec

Title: Re: how to use the Linear Mask in MLT tool
Post by: astroedo on 2016 September 02 13:02:15

It's very simple indeed! ;-)

You must use it for denoising at linear stage: activate the mask checking the "Linear Mask" checkbox.
Create a Preview on your image to test the masking and denoising parameters.
Deactivate the Screen Transfert Function and Check the "Preview Mask" flag.

Set the "Amplification" factor: this is a multiplicative factor applied to the image that enhance it to create a protective mask.
Typical values range from 60 to 110.
Drag and drop the blue triangle of MMT process on your preview: you will preview the mask that will be applied.
Trim the amplification factor and the smoothness factor to get the desired masking effect.

When done Deactivate the "Preview Mask" flag, reactivate the Screen Transfer function and proceed as usual with denoise.

The denosing effect will be applied with the built in masking.

Clear Skies

Title: Re: how to use the Linear Mask in MLT tool
Post by: alcol on 2016 September 02 13:57:16

Hi Edoardo

Very many thanks, easy when you know how. Followed your clear instructions and it all worked. The process is superb, noise has vanished.

Very much appreciated.

Best wishes

Alec

Title: Re: how to use the Linear Mask in MLT tool
Post by: Juan Conejero on 2016 September 03 01:33:30

This may help too:

http://pixinsight.com/examples/M81M82/index.html#Noise_Reduction