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Starnett

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#1 elmiko

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Posted 20 October 2019 - 04:08 PM

So I figured out with some help from another member friend on this site how to download Starnett into Pixinsight. It is a process tool now. When I open a non linear image and open the StarNet tool a little box opens that gives me the choice of 128, 64,32,16, or 8. Is this the file size it will generate? It also has a small box to check off to generate a star mask. I checked the box and drag the triangle onto my image, after a minute it produces a star mask.

Is this the proper way to generate a starless image? I thought it was supposed to do it automatically.

I ended up subtracting the star mask from the image using Pixel Math, and it made a starless image. Am I doing this correctly?

Thanks for anyone's help.


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#2 Salacious B Crumb

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Posted 20 October 2019 - 04:14 PM

I didn't notice any difference when trying different figures. If you uncheck the starmask box it creates a starless image. Either way duplicate your original image first, otherwise you'll loose it.

 

 

- Mikko


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#3 elmiko

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Posted 20 October 2019 - 04:16 PM

Thanks Mikko! Does it take a while to make the starless image?



#4 elmiko

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Posted 20 October 2019 - 04:18 PM

I read in the readme instructions that it can cause Pixinsight to freeze up.



#5 Terry R

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Posted 20 October 2019 - 05:49 PM

Hi Mike.  As Mikko has written.  Untick the Create starmask and starnet++ will generate a starless image.  From here you can go in and clean up the results to suit.   Generally I have to look at the diffraction spikes and the bright stars which leave an artefact in the resulting Starless image.  I tend to leave the stride value at its default value.


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#6 elmiko

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Posted 20 October 2019 - 06:09 PM

Thanks Terry! I appreciate that! So does it take a while to generate the starless image? I have a pretty fast computer.



#7 noodle

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Posted 20 October 2019 - 06:24 PM

stride 64 and stride 128  look the same to me XD

 

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#8 Scott Mitchell

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Posted 20 October 2019 - 07:05 PM

Thanks Terry! I appreciate that! So does it take a while to generate the starless image? I have a pretty fast computer.

Elmiko, I can tell you that on my not very powerful computer (5-6 year old i5 CPU) it takes about 40 minutes to process the images produced by my Canon t5i into a starless version. I'm using the command line version of Starnet, not the Pixinsight version, but I doubt it makes a difference.


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#9 elmiko

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Posted 20 October 2019 - 08:19 PM

Elmiko, I can tell you that on my not very powerful computer (5-6 year old i5 CPU) it takes about 40 minutes to process the images produced by my Canon t5i into a starless version. I'm using the command line version of Starnet, not the Pixinsight version, but I doubt it makes a difference.

Thanks Scott, I tried it out and it takes two minutes to produce a starless image, now my camera is only a 2.1 mega pixel CCD. And I run a i7 32 gb gb ram  HP Omen gaming PC.



#10 elmiko

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Posted 20 October 2019 - 08:20 PM

stride 64 and stride 128  look the same to me XD

 

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Thanks Noodle, I just use the 128



#11 Scott Mitchell

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Posted 20 October 2019 - 08:30 PM

Thanks Scott, I tried it out and it takes two minutes to produce a starless image, now my camera is only a 2.1 mega pixel CCD. And I run a i7 32 gb gb ram  HP Omen gaming PC.

I clearly need to ship you my images to process for me. lol.gif


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#12 Salacious B Crumb

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Posted 20 October 2019 - 09:49 PM

Thanks Mikko! Does it take a while to make the starless image?

Mike as others stated, it might take a few minutes.  

 

 

- Mikko


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#13 elmiko

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Posted 20 October 2019 - 10:31 PM

I clearly need to ship you my images to process for me. lol.gif

That's funny Scott! You don't want me to process your images! Believe me!


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#14 elmiko

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Posted 20 October 2019 - 11:34 PM

Thanks again for your help and advice  Mikko!


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#15 elmiko

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Posted 21 October 2019 - 10:55 AM

Thanks for everyone's help with this matter!! Now to practice!



#16 Jcwillis4

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Posted 21 October 2019 - 01:34 PM

The Stride value is essentially how big an area of your image it analyses at a time.  The higher the number, the faster the process will run.  However, at very high strides (i.e 128) sometimes you'll notice some rough boxy artifacts around big stars.  In those cases, you can lower the stride value, but each lower increases the processing time quadratically.  I use 64 on most of mine and drop to 32 if I have a real bad star, but I don't have a problem waiting a bit longer for it to run.  The image does need to be stretched in order for the process to work right even in Pix insight if I remember correctly.


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#17 Mert

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Posted 21 October 2019 - 03:58 PM

Hi Mike,

 

The smaller the Stride number the longer it takes!

Personally I use the "out of Pixinsight" version to have

a bit more control and use a lot of times 256! ( much

faster )


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#18 Scott Mitchell

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Posted 21 October 2019 - 05:14 PM

Holy cow, that's the first time I've messed with the stride parameter! Maybe 5 minutes at stride value of 256. Result looks as clean as the default stride (which takes about 45 minutes on my machine). 


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#19 elmiko

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Posted 21 October 2019 - 05:53 PM

Thanks, John and Mert for that information! I will have to check it out. I've been using the 128 stride. It takes a minute or two to produce either a starless image or a star mask. But as John mentioned, my larger stars do appear with blocky artifacts.

I will try stride of 64 . 

So as far as using the Starless image to process the image further. The reasoning behind it is you are able to stretch the main object, say it's M27 , you can stretch more details out without the problem of affecting the stars. Correct?

I've done this before, and after, I add the star mask back to the starless image in pixel math to produce the stretched image that has tighter stars. I'm sure there is more that can be done. This is a newbies way.


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#20 PhotonHunter1

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Posted 21 October 2019 - 11:29 PM

I’ve used stride 32 - takes quite a while but the image quality is better IMHO than the 128 (I’ve built a computer that has significant horsepower - beware of using stride settings below 128 unless you have horsepower to spare). Note that you run Starnet against a TIFF file. Leave the starmask box unchecked to create your starless image, checking will create your starmask. It produces a great starmask, that I stretch a bit to create a bit more contrast.


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#21 elmiko

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Posted 22 October 2019 - 12:36 AM

 So should I save my image as a tif. Rather than leave it at the default xism file? Does Starnett work better with a tif?



#22 H-Alfa

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Posted 22 October 2019 - 05:30 AM

Hi! As far as I know it only works with stretched 16bit tiff images (at least the executable version).

I have just started to use it and I have to say that it has changed my processing workflow in a good sense. It's simply amazing!

Have fun dude! :)

Enviado desde mi ANE-LX1 mediante Tapatalk
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#23 astrovienna

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Posted 22 October 2019 - 06:48 AM

 So should I save my image as a tif. Rather than leave it at the default xism file? Does Starnett work better with a tif?

The Pixinsight process will work with XISF files.  I noticed some very slight differences in the result when I ran the process against an XISF vs running the command line against a TIFF, but they were just different.  I wouldn't say one was any better than the other.

 

Kevin


Edited by astrovienna, 22 October 2019 - 06:50 AM.

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#24 elmiko

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Posted 22 October 2019 - 08:04 AM

Thanks Alberto and Kevin. Yes I should have been more clear on whether the XISF files work or not. They do, I was just wondering if I should be using Tif. Files.

Thanks for your help



#25 Jcwillis4

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Posted 22 October 2019 - 09:11 AM



So as far as using the Starless image to process the image further. The reasoning behind it is you are able to stretch the main object, say it's M27 , you can stretch more details out without the problem of affecting the stars. Correct?

I've done this before, and after, I add the star mask back to the starless image in pixel math to produce the stretched image that has tighter stars. I'm sure there is more that can be done. This is a newbies way.

For me, I tend to use the starless as my color data, so I can stretch and noise reduce the crap out of it without worrying too much about the affect on detail.  After I'm done with that, I can combine with a luminance image that is typically the Ha for most targets as that has the most detail, and that's where I do deconvolution and more normal noise reduction.   

 

Another use for this that I'm playing around with more is for HaRGB or Narrowband images with RGB stars.  I take all my narrowband images starless, and then take a bunch of RGB for just the stars.  Then I blend the starless back for nice narrowband data that doesn't impact the stars. That's what I did on my Heart nebula below.

 

get.jpg?insecure

 

Also, sometimes it's just cool to have a starless version of the image, and that can be it's own end result.  When doing Andromeda, I didn't actually use the Starless for anything, but it made this really cool "portrait" view of the galaxy.

 

get.jpg?insecure


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