Summary / comparison of image processing software?

[astrojon77]

Hi,
Has anyone got a summary / comparison of the various image processing and stacking software, with (perceived) advantages and disadvantages?

I started off using DSS and Gimp and was fairly happy - for my basic ability level at the time! 
 
Recently I’ve tried Siril and found the photometric calibration and background extraction are great tools. (But for now I still stack in DSS as I’m used to that…)

Then I saw that lots of you are using PixInsight, so I’m trialing that - and trying to get over the learning curve. 🤪

Then I see others use Affinity Photo, others StarTools etc. 

So back to my question: has anyone got a nice summary / comparison?

Thanks,
Jon

[scotty38]

If you find one I'd like to see it out of interest too 🙂

I have PI, APP and Affinity although I bought the latter before I'd heard of Astrophotography.... All of them are better than I am but I went with PI simply because I'd seen so many good images created with it that I thought at least I will never feel it's the software letting me down. Most of what I see comes down to price and the question of paying (a lot in some cases) for something that you can get for free or cheaper elsewhere.

I would say the support and updates you get in PI are streets ahead of say APP but that doesn't necessarily mean the sw is better but if that is important to you (it is to me) then there's one comparison....

[Budgie1]

I do have comparison images between Photoshop CS3 and Pixinsight.

When I started back into astrophotography, I already had PS CS3 so I stacked in DSS and post-process in PS. When I knew I was going to stick with the hobby I started looking for software which would allow me to do a better job with the post-processing than I was happy with in PS. I went for the trial version of PI and followed some tutorials (I found this one very handy!   ) and this is one of the first images I processed in PI, it's NGC7000 taken with a standard Canon EOS 2000D attached to a Evostar 100ED DS Pro.

First is the best I managed to get with PS and my PI version below and they both used the same DSS stacked image.

I should add the disclaimer that; some on here have far better skills with the likes of GIMP & PS than I do and can produce some spectacular images with those. I use PI because that's what allows me to get the best out my image data.  

HTH.

[The Lazy Astronomer]

I started off with DSS and GIMP, but I got the feeling I wasn't really getting the most out of my images, and I found it quite faffy to do things in it. 

Then I moved to Startools; I liked it generally - it has a relatively simple and (to me anyway) a pretty intuitive interface, and you can knock out a completed image in minutes, but I was never really 100% happy with the way the autodev module stretched the data, particularly the way it stretched the stellar profiles - I tried many different things and just couldn't quite get them to look how l wanted them, which meant I then had to do a fair amount of star reduction, which in turn left them looking slightly artificial within the context of the image.

At the same time, I also switched to Siril for stacking (never really used it for post processing though). Siril has DSS beat for stacking, so I'd recommend you check it out. 

Then I moved to Pixinsight, and got on with it a lot better than I expected. I find the sheer vastness of it's available processes gives so much fine control over every facet of the image and l really like that, but it is a slow procedure to complete an image - I can spend hours playing with settings and different processes!!

I would say Startools gets me to an image that is 90% as good as what I can get out of PI, in a fraction of the time, but if you asked me which image l preferred, it would be the PI one, every time (not sure how much the IKEA effect comes in to play here though...).

[astrojon77]

Thanks all.

I will try Siril for (manual) stacking - so far I’ve just used the scripts. Is there something in particular you think Siril does better than DSS for stacking? (I am intrigued by the idea of applying gradient removal to each light frame before stacking.)

Siril is lacking a curves adjustment tool, right?

Edited January 21, 2022 by astrojon77

[AstroMuni]

7 minutes ago, astrojon77 said:

Siril is lacking a curves adjustment tool, right?

It does have both Asinh and Histogram stretching tools. Asinh preserves colours better.

But it does NOT allow you to do curve adjustments by individual channel

Edited January 21, 2022 by AstroMuni

[astrojon77]

On 20/01/2022 at 19:01, The Lazy Astronomer said:

At the same time, I also switched to Siril for stacking (never really used it for post processing though). Siril has DSS beat for stacking, so I'd recommend you check it out.

I had a go with Siril for stacking today and It did a good job of removing gradients on an image. Also if I save the master frames I guess the whole process will be quicker next time. 

Are there some other benefits you perceive over DSS? Sun-frame selection? Or the actual stacking algorithms / results?

Thanks,
Jon

[astrojon77]

On 21/01/2022 at 10:22, AstroMuni said:

It does have both Asinh and Histogram stretching tools. Asinh preserves colours better.

But it does NOT allow you to do curve adjustments by individual channel

Can you achieve the classic contrast enhancing S-curve with those tools in Siril? I ended up loading my final image into Photoshop to do the final curves tweaks. 

Thanks,
Jon

[The Lazy Astronomer]

17 hours ago, astrojon77 said:

I had a go with Siril for stacking today and It did a good job of removing gradients on an image. Also if I save the master frames I guess the whole process will be quicker next time. 

Are there some other benefits you perceive over DSS? Sun-frame selection? Or the actual stacking algorithms / results?

Thanks,
Jon

I'm not that clued up on the specifics of the algorithms used, so can't comment on that. There's nothing fundamentally wrong with DSS, it's easy to use, but it is essentially adandonware, having not been updated in I-don't-know-how-long. Siril certainly offers more flexibility, and is more comparable to Pixinsight in terms of stacking.

I used DSS exclusively for a year or so (because it's so easy to use), but what made me switch to Siril was an issue l had with a faint, almost checkerboard/grid-like pattern on an image l was trying to stack - I thought it was an issue with my camera or calibration frames, but after some research, I discovered it was actually due to the subframe alignment process in DSS (image was shot over multiple nights, and there was some slight rotational difference between the nights). I tried all the different options I could see in DSS, but to no avail, then I tried out Siril, and sure enough the pattern did not appear in the stacked image (exactly the same raw data). I've stacked using Siril exclusively ever since. 

Edited January 23, 2022 by The Lazy Astronomer
cross through incorrect statement

[almcl]

6 hours ago, The Lazy Astronomer said:

There's nothing fundamentally wrong with DSS, it's easy to use, but it is essentially adandonware, having not been updated in I-don't-know-how-long.

That's not quite the case.  DSS is still being developed, the latest edition is 4.2.6 and this was published in May 2021. 

Dave Partridge who posts here as Perdrix is maintaining the code and there is an active discussion group https://groups.io/g/DeepSkyStacker/topics

 

 

 

[The Lazy Astronomer]

2 hours ago, almcl said:

That's not quite the case.  DSS is still being developed, the latest edition is 4.2.6 and this was published in May 2021. 

Dave Partridge who posts here as Perdrix is maintaining the code and there is an active discussion group https://groups.io/g/DeepSkyStacker/topics

You're quite right - I'll edit my original post, and my apologies to Dave!

I think my impression it was not being actively developed is because the information on the DSS website is not being updated anymore it appears.

[iantaylor2uk]

I use Nebulosity 4 which I think is now free. That is good for basic processing after DSS, and then I may use Affinity for finishing up. Gradient removal in Siril sounds interesting, will have to look into that.

[AstroMuni]

On 22/01/2022 at 19:49, astrojon77 said:

Can you achieve the classic contrast enhancing S-curve with those tools in Siril? I ended up loading my final image into Photoshop to do the final curves tweaks. 

Thanks,
Jon

You certainly can, but paid tools like PS have more functionality in that area.

[AstroMuni]

On 22/01/2022 at 19:47, astrojon77 said:

I had a go with Siril for stacking today and It did a good job of removing gradients on an image.

And in Siril you can get it to remove gradients on every image in the stack before stacking as well. This can help in certain cases.

[AstroMuni]

A few features I like in Siril: (as we speak its with ref to v1.0.0-rc2)

- Photometric calibration

- Background gradient removal

- Pixel math is new and has some great possibilities (havent tried in anger yet)

- Easy to combine multiple nights sessions (even if they have different calibration frames) using Sirilic

- Very active developers

Features lacking:

- masking

- star removal

- noise reduction (only median filter is available)

Edited January 24, 2022 by AstroMuni

[malftobe]

On 20/01/2022 at 15:45, astrojon77 said:

Hi,
Has anyone got a summary / comparison of the various image processing and stacking software, with (perceived) advantages and disadvantages?

I started off using DSS and Gimp and was fairly happy - for my basic ability level at the time! 
 
Recently I’ve tried Siril and found the photometric calibration and background extraction are great tools. (But for now I still stack in DSS as I’m used to that…)

Then I saw that lots of you are using PixInsight, so I’m trialing that - and trying to get over the learning curve. 🤪

Then I see others use Affinity Photo, others StarTools etc. 

So back to my question: has anyone got a nice summary / comparison?

Thanks,
Jon

How are you getting on with the  Pixinsight trial Jon? Are you finding it easy enough to pick up? I hope to trial it one day when I have some decent data!

Interesting to know about Siril and the additional tools! I may give it a whirl. 

Edited January 24, 2022 by malftobe
Spelling

[astrojon77]

@Budgie1 thanks for the links to Mitch’s tutorials. I’m going to give them a try right now. 

@malftobe I have only spent a few hours with Pix Insight so far. I’m still getting used to the UI… the developers have chosen different icons and paradigms than I think is the “norm”. (For example, it came as a surprise to me that the tools don’t preview automatically. You can create preview windows.)

Noob error: I spent some time looking for the BatchPreProcessing script (AKA “BPP”) that was mentioned in lots of tutorials, but was missing from my version. I found reports from people who seemed to have a similar problem and followed the steps to reinstall scripts. No luck. Then it dawned on me that the BPP script might have been retired and replaced by the Weighted Batch Pre Processing (WBPP) script that appeared at the bottom of the menu… and spent another 10 minutes Googling to prove that to myself. 🤨 Off to a good start. 

I also watched some rather discouraging tutorials for PixInsight on YouTube… they seemed complex, with lots of steps, lots of magic values in the tools… and honestly, the results looked a bit “meh”… And I got rather fed up of people saying things like “I don’t really know what these parameters do, but they work for me and my images”  

I came away feeling that PI has the appearance of a serious, scientific tool, but that in the tutorials I watched some of the people were just trial-and-errroring their way through it. At which point I thought, “why aren’t you just doing this in Photoshop?!” (Or Affinity Photo or Gimp)

Then I sort of came to the opinion that once your image is calibrated, registered, stacked, background calibrated and stretched*, you have finished the rigorous “science” phase and are starting an artistic phase. And maybe PI is not the best artistic tool.

I don’t doubt that PI has a wide range of tools and a lot of configurability, I’m just not sure that I need them - or can make good use of them. Yet.

I’m by no means a Photoshop guru, but watching someone create a star mask in PS and then apply noise reduction to the background… well it makes sense to me and the UI paradigm is more familiar.

But then I also watched someone spend a while doing star minimisation in PS and I preferred the image beforehand. 😝

Jon

* part of this investigation has involved me trying to learn the correct sequence of operations (workflow) and which software packages do them well etc.

Edited January 25, 2022 by astrojon77

[malftobe]

52 minutes ago, astrojon77 said:

@Budgie1 thanks for the links to Mitch’s tutorials. I’m going to give them a try right now. 

@malftobe I have only spent a few hours with Pix Insight so far. I’m still getting used to the UI… the developers have chosen different icons and paradigms than I think is the “norm”. (For example, it came as a surprise to me that the tools don’t preview automatically. You can create preview windows.)

Noob error: I spent some time looking for the BatchPreProcessing script (AKA “BPP”) that was mentioned in lots of tutorials, but was missing from my version. I found reports from people who seemed to have a similar problem and followed the steps to reinstall scripts. No luck. Then it dawned on me that the BPP script might have been retired and replaced by the Weighted Batch Pre Processing (WBPP) script that appeared at the bottom of the menu… and spent another 10 minutes Googling to prove that to myself. 🤨 Off to a good start. 

I also watched some rather discouraging tutorials for PixInsight on YouTube… they seemed complex, with lots of steps, lots of magic values in the tools… and honestly, the results looked a bit “meh”… And I got rather fed up of people saying things like “I don’t really know what these parameters do, but they work for me and my images”  

I came away feeling that PI has the appearance of a serious, scientific tool, but that in the tutorials I watched some of the people were just trial-and-errroring their way through it. At which point I thought, “why aren’t you just doing this in Photoshop?!” (Or Affinity Photo or Gimp)

Then I sort of came to the opinion that once your image is calibrated, registered, stacked, background calibrated and stretched*, you have finished the rigorous “science” phase and are starting an artistic phase. And maybe PI is not the best artistic tool.

I don’t doubt that PI has a wide range of tools and a lot of configurability, I’m just not sure that I need them - or can make good use of them. Yet.

I’m by no means a Photoshop guru, but watching someone create a star mask in PS and then apply noise reduction to the background… well it makes sense to me and the UI paradigm is more familiar.

But then I also watched someone spend a while doing star minimisation in PS and I preferred the image beforehand. 😝

Jon

* part of this investigation has involved me trying to learn the correct sequence of operations (workflow) and which software packages do them well etc.

Cheers for the update Jon, really interesting and amusing insights. You sound similar to myself, I know my way round the basics in photoshop from general photography - I have much to learn on the astro side and PI does look complex! 

For some reason I thought it was a 7 day trial for PI, but I had a look after I posted and it’s  45 days, so a bit more relaxed timeframe to get head around the software before the trial would expire! The complex tutorials gave me pause for thought hence the question.

I like your idea of the separation of the science phase and artistic phase.

Your investigation into what packages do well at what has certainly opened some different software options up that I was not aware of before you started the thread, so thank you Jon. 

[scotty38]

@astrojon77 If you're still interested in giving PI a go then, if you haven't already, check out the tutorials from Adam Block as he does explain the tools.

He has 20 plus videos on WBPP alone, here's the first:

 

[astrojon77]

After spending a bit more time with PixInsight - and finding the WBPP script was taking rather a long time - I had a little look into what was happening in task manager and did a little stacking test/benchmark.

I was working with 128 light frames (9MP FITS, all same exposure length), 40 flat frames, 40 bias frames, 50 darks. That's a total of ~4.5GB of input data.
My PC is a Win 10, Core i5-4690 (4 cores, 4 threads), 16GB RAM and has both an SSD and an HDD.

Anyway, here are the measurements:

Application	Script / Process	SSD	HDD	Temp data
DeepSkyStacker	Register + Stack (Median Kappa Sigma)	5 mins 40s	7 mins 45s	~4GB
Siril	OSC_PreProcessing	5 mins 49s	26 mins 40s	27.3GB
PixInsight	WeightedBatchPreprocessing	30 mins 5s	32 mins 49s	32.1GB

Guess where my astro photos were being stored to begin with? Yes, the HDD... 😬

I mostly kept the default app/script parameters and tried to clean everything between runs, with temporary files and master frames deleted so they had to be regenerated.
PixInsight has the default setup for "Swap storage directories" - just one entry, on an SSD. I may tweak that.

I will check the PixInsight SSD time - I would have expected a bigger improvement, like Siril saw.
Note that DSS was NOT asked to generated temporary files for the calibrated and registered images.

[scotty38]

Is Siril creating the final integration(s) in that time too?

 

Also there are some parameters you may want/need to change in Global Preferences for PI for SSD performance.

Edited February 3, 2022 by scotty38

[astrojon77]

Yes, Siril created the final integration. 

I should have some time this weekend to investigate this further 

[The Admiral]

Anyone with AstroPixel Processor experience care to chip in? I use it but I'm very much a noob.

Sometimes I look through the offerings submitted to the IKI Observatory processing competitions, and some who use PI seem to employ every tool known to man , and yet when I look at the resulting image, dare I say it, I think to myself "What was all the effort for?". I'm inclined to think that with PI, it is excellent in the right hands, but one does need to temper the selection of tools, just because they are there. Your view may, and probably will, vary of course.

I'll get me coat!

Ian

[wornish]

I use Astro Pixel Processor and it does a really good job.  It is very easy to use and handles mosaics as standard, way simpler that Pixinsight.

The latest version now has a star removal tool which works well.

It claims it can align images with comets, not tried that though.

 

 

Edited February 5, 2022 by wornish

[JonCarleton]

I take a different approach, in that I tend to get a large number of bad images, due in part to wind, and in part to being directly under a jet approach to the Atlanta airport (one of the world's busiest).

I use ASTAP for its ability to grade images and allow me to eliminate that bad ones without having to view each fits image.  My  current image size is 39M, and every fits viewer I have ever used is slow with images that large.  I do view each one manually that passes the grading process to be sure before post processing, but there is no point going through all the ones with clouds, jets, wind jitter and other issues.  ASTAP will allow me to set a grading percent and rename the fails to .bak for easy deletion.  I use ASTAP for my plate solving anyway, so it isn't as though I am adding additional software.   And, although ASTAP's grading process is pretty good, it does not eliminate photos with satellite or meteor trails.  In general, these disappear with a large number of images to stack, so that isn't really a serious problem.

ASTAP will stack and does a fair job, but Siril does a better job and has more bells and whistles, so I do the final stack with Siril.  I'm still using StarTools for post.  I probably should switch to PixInsight, but haven't yet.