GeneralisedHyperbolicStretch Process Module

Mike1485

Well-known member
Dear fellow astrophotographers

Since our first release of the Generalised Hyperbolic Stretch script, there has been a huge uptake in its use, due to the control and flexibility provided by the unique equations and methodology. We are grateful for the interest shown and the constructive feedback we have received.

We are now pleased to offer the GHS process module for PixInsight. This brings the benefits of the GHS equations, offered by the script, and integrates fully into the PixInsight environment, including the real-time preview and the readout functionality, as well as taking advantage of the performance improvements possible with compiled multi-threaded code. The process currently requires PixInsight 1.8.9-1.

Like the script, we are providing the new process free of charge. To obtain the GHS process module you only need to have the current ghsastro repository in your managed repositories list – the address is: https://www.ghsastro.co.uk/updates/.

Once downloaded, the GHS process will also be available as an External Scriptable Object making it easy to incorporate into your own PixInsight scripts. Full updated documentation is available from within the module, describing its features and use.

We will continue to make the script available for download from the same repository address. The script has been modified to take advantage of the new process where possible/available.

As ever, we welcome all comments and feedback.

Clear skies and happy stretching!

Mike Cranfield and Dave Payne
 
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Folks,

Mike did all the work in porting this over to a compiled process - Mike just used me as a guinea pig, but am I ever glad he did. As a process, I essentially keep GHS open all the time now - monitoring the histogram and often tweaking the stretch ( for example after HDRMT, or after LRGB combination, or after adding back in the stars, etc. etc.). Thanks so much Mike for all your work. I am loving the process/module version and that's no hyperbole nor stretching the truth.

Dave
 
I had a problem with installing the new process. It downloaded ok from the depository but when loading I got the following error message:

<* failed *>
*** PixInsight API Error: Module: /opt/PixInsight/bin/GeneralizedHyperbolicStretch-pxm.so
Cannot load library /opt/PixInsight/bin/GeneralizedHyperbolicStretch-pxm.so: (/lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.33' not found (required by /opt/PixInsight/bin/GeneralizedHyperbolicStretch-pxm.so)): Module load error
* Scripting resources updated.
57 of 58 module(s) installed.

I'm running Ubuntu 20.04.5 LTS linux.

Gordon
 
Thank you for this. I have a low-spec computer and this process version provides a significant speed boost over the previous script version.

Mr Bee@101.
 
I had a problem with installing the new process. It downloaded ok from the depository but when loading I got the following error message:

<* failed *>
*** PixInsight API Error: Module: /opt/PixInsight/bin/GeneralizedHyperbolicStretch-pxm.so
Cannot load library /opt/PixInsight/bin/GeneralizedHyperbolicStretch-pxm.so: (/lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.33' not found (required by /opt/PixInsight/bin/GeneralizedHyperbolicStretch-pxm.so)): Module load error
* Scripting resources updated.
57 of 58 module(s) installed.

I'm running Ubuntu 20.04.5 LTS linux.

Gordon
Hi Gordon

The Linux version of GHS was compiled against Linux Kubuntu 22.04. It looks like your installation of Linux is older - the current desktop Ubuntu distro is 22.04. I presume your 20.04 version has an older version glibc. Can I suggest upgrading to the latest Ubuntu version?

I hope this helps
CS, Mike
 
Thank you, again, Mike and Dave for this new module!;)
I used it a bit a works very well.
Jordi
PS I specially love the Fine adjustment control!?
 
Is there a way to set 24 LUT in the real time preview?


Screenshot 2022-11-04 120330.jpg
 
To help make it responsive and "real-time" the real time preview uses a 16bit integer representation of your image. I'm afraid this is not changeable by the end user. That looks like a great image ... nice framing!
 
Using the Process Module version, I am having trouble consistently getting a readout on the Graph window of the x,y position of the cursor and the Level and K values. It shows up briefly once then I can't seem to get it back. Using the Utilities based script, works all the time. User error?

Like most people who've put a bit of time into trying this, I love it and thank you for the work you've done. I still have to resort to HT and CT for some things, but generally GHS is my first choice for going non-linear. Awesome work!
 
Using the Process Module version, I am having trouble consistently getting a readout on the Graph window of the x,y position of the cursor and the Level and K values. It shows up briefly once then I can't seem to get it back. Using the Utilities based script, works all the time. User error?

Like most people who've put a bit of time into trying this, I love it and thank you for the work you've done. I still have to resort to HT and CT for some things, but generally GHS is my first choice for going non-linear. Awesome work!
The process should be: move the cursor to the point you want the information for, wait a second and the information should pop up - move to another point, wait a second and the new information will appear - repeat at will! Does this not work for you?

Thanks for your kind remarks about GHS - I'm glad you are finding it useful.

CS, Mike
 
Strangely, the GHS process frequently crashes PixInsight for me (macOS 12.6.1, Intel i7 MacBook Pro). The script never crashed, even once.
 
Strangely, the GHS process frequently crashes PixInsight for me (macOS 12.6.1, Intel i7 MacBook Pro). The script never crashed, even once.
That is odd - I am on a Mac and have no issues although it is an M1 Mac. Can you pinpoint what you are doing when it crashes? Does it crash completely out of PixInsight? If not, are there any messages in the Process Console that could shed some light on what's happening? I am happy to investigate further but I need a bit more to go on if you can please. Thanks.
 
It usually happens while I’m looking at a real-time preview and dragging one of the sliders to see the effect. But it’s random, I don’t have a “recipe” to replicate it yet. When it crashes, it crashes the entire PixInsight instance.

Also, the process window doesn’t show the icons of the various histogram modes for me:
GHS.jpg
 
I'm having the same issue with GHS process on a i7 Macbook Pro with MacOS 13.0.1. When I have the preview open and touch any sliders Pixinsight crashes always either immediately or couple of seconds later.
 
I'm having the same issue with GHS process on a i7 Macbook Pro with MacOS 13.0.1. When I have the preview open and touch any sliders Pixinsight crashes always either immediately or couple of seconds later.
Are you also missing the icons on the buttons at top left of the interface? Does the issue apply on a specific image or on all images? Did you install GHS using the PI automated process via the https://www.ghsastro.co.uk/updates/ repository, or did you install manually? So far I have been unable to duplicate the issue.
 
Are you also missing the icons on the buttons at top left of the interface? Does the issue apply on a specific image or on all images? Did you install GHS using the PI automated process via the https://www.ghsastro.co.uk/updates/ repository, or did you install manually? So far I have been unable to duplicate the issue.
No, I have the icons, see screenshot. I tried GHS process on a couple different images even from different cameras (with different resolution) but it always results in Pixinsight crashing when I pull the stretch factor slider. Sometimes it crashes while I'm still pulling the slider some other times after I stop and release the mouse button. Basically never worked for me.
I installed GHS via the official repository, had no issues installing.
 

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I am unable to reproduce this behaviour so it's difficult to know what is going on. Have you tried using the script version? The preview update works completely differently there so I would hope you won't experience crashes moving the sliders in the script. When you apply the stretch it will use the process if you have it installed. This may work OK for you, but if not you can disable this and avoid the process altogether by setting an option in the preferences dialog (click on the spanner/wrench in the bottom right corner of the main interface). If I do track down the cause of your process crashes I will post back here.

CS, Mike
 
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