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WBPP v.2.0.2 Failure Generating Image Descriptors

Alan Karty
in PixInsight
Adam,
What does the following extract from my process log mean?  What is wrong?

Computing descriptors for image 1 of 20
[2021-02-20 05:25:50] C:/Users/Alan Karty/OneDrive/Pictures/NGC346/calibrated/light/cosmetized/NGC 346 v2 B -25 300 BIN1 PA000 E 20201006 225945_c_cc.xisf
[2021-02-20 05:25:50] Loading image: w=4500 h=3600 n=1 Gray Float32
[2021-02-20 05:25:50] 146 FITS keyword(s) extracted.
[2021-02-20 05:25:50] 
[2021-02-20 05:25:50] StarDetector: Processing view: Image01
[2021-02-20 05:25:55] 39459 star(s) found
[2021-02-20 05:25:55] 0 PSF fittings
[2021-02-20 05:26:01] 
[2021-02-20 05:26:01] ** Warning: No convergence in MRS noise evaluation routine: using k-sigma noise estimate
[2021-02-20 05:26:02] ------------------------
[2021-02-20 05:26:02] FWHM         : -
[2021-02-20 05:26:02] Eccentricity : -
[2021-02-20 05:26:02] SNR          : 138.699
[2021-02-20 05:26:02] ------------------------
[2021-02-20 05:26:02] Failed to measure C:/Users/Alan Karty/OneDrive/Pictures/NGC346/calibrated/light/cosmetized/NGC 346 v2 B -25 300 BIN1 PA000 E 20201006 225945_c_cc.xisf
[2021-02-20 05:26:02] Image will be ignored.

Thank you.
Alan

Comments

  • BlockHeadBlockHead
    Hi Alan,

    Very likely the data is noisy or not calibrated correctly. 39,000 "stars" sounds like an awful lot of them!
    II am assuming this is the weighting portion of WBPP?
    (I am not certain... )
    You should definitely look at NGC 346 v2 B -25 300 BIN1 PA000 E 20201006 225945_c_cc.xisf and see what it looks like!

    -the Blockhead
  • Alan Karty
    Hello Adam,

    This is happening on other data.

    Computing descriptors for image 2 of 24
    [2021-04-15 03:25:39] C:/Users/Alan Karty/OneDrive/Pictures/NGC6752/calibrated/light/cosmetized/NGC 6752 B -25 300 BIN1 PA000 E 20200821 193524_c_cc.xisf
    [2021-04-15 03:25:39] Loading image: w=4500 h=3600 n=1 Gray Float32
    [2021-04-15 03:25:39] 146 FITS keyword(s) extracted.
    [2021-04-15 03:25:39] 
    [2021-04-15 03:25:39] StarDetector: Processing view: Image01
    [2021-04-15 03:25:42] 12323 star(s) found
    [2021-04-15 03:25:42] 0 PSF fittings
    [2021-04-15 03:25:48] 
    [2021-04-15 03:25:48] ** Warning: No convergence in MRS noise evaluation routine: using k-sigma noise estimate
    [2021-04-15 03:25:50] ------------------------
    [2021-04-15 03:25:50] FWHM         : -
    [2021-04-15 03:25:50] Eccentricity : -
    [2021-04-15 03:25:50] SNR          : 984.904
    [2021-04-15 03:25:50] ------------------------
    [2021-04-15 03:25:50] Failed to measure C:/Users/Alan Karty/OneDrive/Pictures/NGC6752/calibrated/light/cosmetized/NGC 6752 B -25 300 BIN1 PA000 E 20200821 193524_c_cc.xisf
    [2021-04-15 03:25:50] Image will be ignored.

    When I examine the cosmetized image and compare it a cosmetized image that was successfully measured, I notice that the background is very dark.  At a selected point, the successful image had a K = .00082, while the unsuccessful image at the same point had a K = .00004.

    Any ideas?

    Alan
  • BlockHeadBlockHead
    Ah... the dark background!
    Something is being black-clipped during calibration.
    An oversubtraction. Are there actually zeros in your dark image?
    This sounds like a calibration issue!

    -the Blockhead
  • Alan Karty
    Yes.  I located a pixel with K = .00000.  The first light frame (B) was measured, and all remaining 23 B frames were not measured.
  • BlockHeadBlockHead
    Can you make this image available for inspection?
    -the Blockhead
  • Alan Karty
    Is xisf allowed?  What is the file size limit?
  • BlockHeadBlockHead
    You will have to put it on a cloud drive somewhere for me to download. 

  • Alan Karty
    https://1drv.ms/u/s!AtHc9a_3_v7thOcYU_KfcEAhaNGr2Q?e=0agRf2

    1 - measured
    2 - not measured
  • BlockHeadBlockHead
    This looks like a mis-matched dark frame or a bad dark frame subtraction to me. 
    (You didn't try to optimize did you?)
    I colored all of the zeros red in your image. It looks like an over subtraction of a dark frame.
    This would agree with the idea that the noise evaluation did not succeed. 
    PI is trying to tell you something here I think.
    -the Blockhead
    Capture.JPG
    2490 x 1714 - 716K
  • Alan Karty
    Well, I did a little experimenting.  For this globular cluster, I had picked Cluster for the Weighting Parameter and failed as described.  When I switched to Galaxy, all turned out well.

    Any thoughts?  I feel a finger wagging :) 
  • BlockHeadBlockHead
    I am not certain why the weighting would matter. 
    Your data is not optimal- there is oversubtraction by what appear to be hot pixels. 
    As I mentioned, this is due to a bad dark, old dark, or in correct calibration configuration.
    (just because a process succeeded in executing does not mean the result is optimal)
    -the Blockhead 
  • BlockHeadBlockHead
    edited April 2021
    Just to follow up... is this your data?
    (looks like it is from Deep Sky West)
    This was a 300 second exposure that was calibrated with an 1800sec exposure.
    This strengthens  my argument. There would be a potential over subtraction of the dark current and a definite (expected) over-subtraction of hot pixels. I would venture to guess this is an old dark compared with your newer data (but cannot tell without seeing that). 

    Please examine the FITs header. 
    -the Blockhead 
  • Alan Karty
    Thank you for your reply.  Prior to switching the Weighting Parameter, I did rerun with 300 sec darks but the error still occurred.  The data is from DSW to which I have officially subscribed.
  • BlockHeadBlockHead
    If you had matched darks, did you turn off optimization?

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