PixInsight use of mask to apply LightVortex settings with MLT

[+Derbyshire Dave]

Thanks to Chris for organising the PI discussion last night, of which I see he has just posted the video. The topic wasmasks.

 

I promised to get together the information on noise reduction, using MultiscaleLinearTransform(MLT), particularly using the settings on the LightVortex website.

 

You can fin LightVortex noise reduction information here.. from my experience. it's a really good set of values that work well

 

https://www.lightvortexastronomy.com/tutorial-noise-reduction.html#Section1

 

I have set up a PI with the appropriate settings. PM me with your e-mail address and I'll send you the icon file, which you can merge into your PI icons.

 

 

So... The process:

1)The image below shows the MLT process, with the LightVortex settings loaded in. In the background is an image of the SOuld Nebula in Ha.

 

 

2)In the image below notice..

a)The background image is unstretched. You can tell this by the green bar on the name tab at the side

b)The foreground image has been stretched to the same level. This was done by dragging the STF stretch to the base bar of the histogram tool, then dragging the triangle on the histogram tool to back to the image. We know that it is stretched by the fact that there is NO green bar on the name of the image.

c)Note that I have changed the name to 'DavesMask' by right clicking on the image and setting the identifier. I liked to do this becasue it the image is later minimise, you can see what it is.

 

 

3)I then dragged the mask on to the unstretched image by dragging the vertical bar that says DavesMask, and droppinmg it just below the "SoulHa47" green barred tab.

In the image below, note that

a)The namebar has turned brown, this signifies that a mask is in play

b)The mask is show in red, but it is the wrong sense (Inverted to what we want)

 

 

 

4)In the mask menu I then selected "Invert Mask" Now the stars are covered and protected.

 

 

5) I then hid the mask and zoomed in to 1:1. You can clearly see the noise..

 

6)Dragging the MLT process onto the image clearly improves the nosie, but the stars are protected. (See below)

 

 

 

 

As I said earlier, PM me with your e-mail address, and I can send you the process icon to save you setting it all up..

[+Graham]

That looks impressive Dave.

I will drop you my email.

Thanks

[+Graham]

Thanks for that Dave.

It loads up a treat.

All I need now is a few clear night to get some data so I can try it out.

[+Derbyshire Dave]

Excellent. Are you going to join us on the next forum...