DBE (or ABE) on StarXTerminated Linear Image Question

Hi Adam -

I have a question on starless images and then running either DBE or ABE on them.

I've applied ABE (DBE does the same thing) on the attached image and it looks to me like ABE has significantly stretched the result. Is this what you'd expect?

An example short workflow example is in the attached PDF and I've also included a dropbox link to my example image here: 

Thanks for taking a look and even more thanks for your great tutorials!

Best -
- Dan
image

Comments

  • Hi Dan,

    It is very difficult for me to check out everyone's images...I get 20 requests a day. :)
    But I think I have an idea... could you please watch this video? (or confirm you have)


    -the Blockhead
  • edited August 2023

    Hi Adam –

    I’m a multiple year experienced PI user. I’m hesitant to claim significant expertise in damn near anything since I’m still learning, still make mistakes and sometimes forget things. Astrophotography is and has been a passion of mine for quite some time now.

    Thanks for the link. I’ve rewatched the STF/Histogram video again on the off chance that I forgot something.

    The problem I’m seeing appears in both of the recent 1.8.9 PI releases.  I don't remember seeing this behavior before.

    In my PI installation, on a starless linear image, ABE/DBE is changing values in the image from near 0.09  before ABE/DBE to near 1.0 after ABE/DBE.  This is verified by the Statistics Panel, by cursor readout K values and by being able to see the offending pixels in a non auto STF stretched image.

    The PDF I provided shows this (just a few pages and is mostly image screen grabs) and has the statistics panel and cursor readouts to verify.

    I can't recall ever seeing ABE or DBE change a value in an image (not an STF stretch but in the image) from 0.09 to near 1.0 before.

    Best –

        -  Dan

  • edited August 2023
    Oh... I see.
    I do not see this behavior with ABE or DBE at all. I manipulated your image... no issues. The values are not changed. 
    There is something else going on. 

    Nothing is stretched right?


    -the Blockhead
  • 100% no stretch. Thanks for taking a look. I'll try a clean PI reinstall. 

    Thanks again - I really appreciate your time and effort,

    - Dan
  • This is an excellent case of needing to create a video to record what you are doing. 
    What you are experiencing is quite dramatic and I would really love to see an explanation. 

    -the Blockhead

  • Hi Adam - Video created and available here: 

    Adam
    Block - DBE - Video and Files

    Sorry for the delay in responding. It turns out there is a somewhat related post in the PixInsight Forum on 11/30/2023. 

    Thanks again.

    - Dan


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