Remove LP - white image

Update with success... 🤩 

Processed separately 2 sessions with Ha-O3 extract Ha and Ha-O3 extract O3 obtaining the following 4 master lights:

S1_Ha S2_Ha S1_O3 S2_O3

Combined Ha and O3 for each session to have: S1-S2_Ha and S1-S2_O3.

Normalized. Created HOO palette in RGB combine tool. 

But I can't understand why processing the 2 sessions at the same time it didn't work...

That is indeed weird, usually the white result indicates an issue in the background of the data possibly. I wonder if that would happen without some of the calibration data as well.

I used S1-S2_Ha and S1-S2_O3 files to make various test on RGB combine. 

Some different palette combinations gave the same error: complete white image when "neutralize background" is checked  or when using light pollution tool.

HOO1 and HOO2 OK

HSO1 and HSO2 NO

SHO1 OK 

SHO2 NO

Any manual modification of the slider both in SHO and HOO palette gave the "white image "error...

But the astonishing behaviour of APP is....listening...

2 days ago I created HOO modified palette, changing the sliders for my taste, using the above 2 files. No problem: it works.

Now I replicated exactly the same HOO combination using exactly the same 2 files...And ERROR: white image.

Other weird thing..

Once I started doing remove light pollution on HOO combination that seemed to work, after 3 times, the problem appeared...

It has been almost 2 months since APP create so many errors to me that I'm honestly thinking to switch to PI.. I have been using the same files from the same camera and scope for 2 years so it's completely crazy thing. And hours and hours of wasting times doing test on PC...

Can you have a look to the files, please? And experiment by yourself trying to give a reason for this annoying APP beahaviour.

Thanks

Sure thing, you can upload them (please include at least your master calibration files as well as well as a few single subs);

Go to https://upload.astropixelprocessor.com and for the username and password, use: upload

Create a directory named “ippiu-whiteOutIssue” and upload in there. Thank you!

I uploaded 2 sessions with each its own master calibration files.

https://upload.astropixelprocessor.com/index.cgi?launchApp=SYNO.SDS.App.FileStation3.Instance&launchParam=openfile%3D%252FAstroPixelProcessorUpload%252Fippiu-whiteOutIssue%252F

Here another example of weird APP behaviour. 

Same master flat and master dark used for both DSO....

Here they works

Why the same 2 above master calibration files cause this problem??!!??!!

for some months now the program has never worked well and it always gives me problems even though I have never changed my workflow for 2 years.

Thanks for your cooperation and support

I also have frequently encountered this white-out problem.  I have found no rhyme or reason.  I give up and take the fits to other programs.  Definitely not nice to encounter.  

Chances are still that it's data related as it's not happening with a lot of users, I'll investigate thanks for uploading! If it's a bug then we'll be sure to tackle that.

Ok, to start with the first bit, using APP 1.083 beta 2 and no extraction of filter data (just to see if that works, as it may point to a signal issue in one of the channels if the extraction fails). NGC1491, session 1 works fine also with the LP tool, with/without normalization:

Session 2:

Combination, works, but when selecting the LP tool it indeed has a white-out! That is odd, I'll now forward this data to Mabula to see if he can find if it's a bug. The data, to me, looks normal.

Ok, I found the issue. The autostretch is not working correctly, Mabula knows about it. Apparently this can happen in case of some artefacts at the stacking borders. He's looking into improving it a bit.

@vincent-mod

Perfect. Important is that is not my files corruption or APP failure or other files-APP related problem...

When I uncheck "Auto" besides DDP everything works flawlessy as usual.

Thanks Mabula and Vincent for your support

You're most welcome and sorry for the months of frustration. I hope this can still get fixed before the next version is out.

Vincent, wait a moment...Arghh...

I was able to process the following SHO palette until HSL selective color tool with the trick of unchecking Auto DDP..

I was able to save in .tiff as well..

But now APP is unable to open the files that itself has created: white-out problem. Even unchecking DDP auto. Close and reopen the software. Tried with all 3 APP versions..Combinations of check and uncheck neutralize and auto DDP: same white-out problem

Can you please kindly have a look to these 3 files?

Thanks a lot for your help

https://upload.astropixelprocessor.com/index.cgi?launchApp=SYNO.SDS.App.FileStation3.Instance&launchParam=openfile%3D%252FAstroPixelProcessorUpload%252Fippiu-whiteOutIssue%252F

Darn, I hoped that was it. I think it's still the autostretch, you can switch that off but the problem lies in that the sliders are all the way to 0 for the stretch. I'll inform Mabula with your new data as well.

@vincent-mod

I'd like, of course, have the ability to have autostretch working to see what I'm doing on the image. How can I modify the image if I can't see it stretched? 

The trick of uncheck "Auto" in DDP or check neutralize worked and let me create SHO and modify it all the way to the last HSL tool. But when I reopened those 2 files created by APP, it didn't open them as it had done before (even utilizing above tricks) 

Mabula is looking at it at the moment, I hope it gets improved upon for this release.

Posted by: @vincent-mod

Mabula is looking at it at the moment, I hope it gets improved upon for this release.

What does "At it" mean?? Specifically to my 3 files?

Or does he look at the problem itself?

Given I've analyzed your first dataset issue and it seems to be the fact that the auto-stretch is going wrong, that is the "at it", which likely points to the underlying overall problem.

I reportet the same issue last year here https://www.astropixelprocessor.com/community/rfcs-request-for-changes/1-081-neutralize-bg/

Today i have the same effect on a two panel mosaic, and i can conclude that is definitely an autostretch bug

I do two version of the mosaic

version A: no LNC and MBB

version B: LNC level1 and MBB 13%

Just entering the remove light pollution tool with version B create the issue, you can see the autostrecth set Black=0 and ST = 0.00001, while with version A the autostretch is ok

Just setting the Black and stretch parameters of the version A, and the without disappear, the image is ok and i can proceed with the processing, so the image data are not corrupted, is an autostretch visualizazion bug.

@fendium

Grazie mille per questo semplice ma fondamentale "trucchetto"...

Thanks so much for such a great fundamental trick...

Hi @ippiu, @fendium, @vincent-mod, @andynowlen

Thank you all for reporting this issue.

The issue has been fixed! APP 1.083-beta3/stable will include this fix and this will be released soon.

The issue was caused by a bug in the autostretch algorithm leading APP to think that background values were extremely low, leading to a super-stretch white-out... The issue is robustly solved so should never happen again in the next version of APP.

@ippiu, i have tested it on all the data that you uploaded and all is fine now 😉

Mabula

@mabula-admin

Thanks.

I'm looking forward to testing the new 1.083 stable version....I hope "soon" will be in 2 weeks and not in 2 years....:)