Author Topic: Introduced lines into debayered images.  (Read 907 times)

Offline bulrichl

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Re: Introduced lines into debayered images.
« Reply #15 on: 2019 February 23 01:44:48 »
The sensor of the QHY8L has dimensions of 3110 x 2030 pixels. Your image has a width of 3040 and a height of 2016 pixels. Nevertheless your image has dark borders (however they are not black!), the effective image has only 2777 x 2010 pixels. This is very odd.

As Rob noted, the FITS file was written by PixInsight and not by a capturing software. I can imagine two different possibilities:

1) An unsuitable driver was used for your camera or
2) the image was already processed in PixInsight.

One needs a subframe that is stored by the capturing software in order to analyze the issue further.

Bernd

Offline Mariner10

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Re: Introduced lines into debayered images.
« Reply #16 on: 2019 February 23 17:07:40 »
Well the mystery just deepens because these images have never been in PI, they just sit in a folder on my laptop waiting to be processed.
I'm thinking that I might just need to bin the lot and wait until next summer although March in a couple of weeks is an option.
It's frustrating that's for sure.
So if you're out of options then I think I might just do that.
Cheers.

Offline bulrichl

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Re: Introduced lines into debayered images.
« Reply #17 on: 2019 February 24 01:26:28 »
I am talking of the original images out of the camera - we would need to see one of those. These files were saved by some software. Perhaps you could tell us which capturing software did you use for capturing (e. g. APT, SGP, or software of the camera manufacturer...)?

Bernd

Offline Mariner10

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Re: Introduced lines into debayered images.
« Reply #18 on: 2019 February 24 18:54:07 »
Hi Bernd,
The image I dropped into dropbox was an original, straight from the camera which is a QHY8L using EZCAP as the preferred software for that camera.
The images were taken in 2016 (from memory as I don't have them in front of me at the moment) but now that I think about it I had an issue with calibration files not being the same geometry as the original images so that is more than likely why the the FITS were written by PI.
So I would have tried to calibrate them without success so was forced to alter the dimensions of the originals to that of the calibration files. I wouldn't have thought that would cause the lines but it might explain the dark edges.
Sorry, I should have remembered that but the issue still exists at the very start of the processing procedure.
Cheers.

Online pfile

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Re: Introduced lines into debayered images.
« Reply #19 on: 2019 February 24 21:42:30 »
the image you posted *can't* be straight from the camera because the fits header indicates it was written by pixinsight...

anyway if indeed you had to alter some of the calibration images you may have cropped them on a non-bayer matrix boundary and that can definitely screw everything up.

rob

Offline chris.bailey

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Re: Introduced lines into debayered images.
« Reply #20 on: 2019 February 25 00:36:08 »
If you downsample that image by a factor of 2 (to destroy the bayer pattern) the vertical pattern is still there so I think it happened at capture time. Electrical interference, low voltage to the camera, wrong driver.


Offline Mariner10

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Re: Introduced lines into debayered images.
« Reply #21 on: 2019 February 25 16:06:23 »
Thanks guys, if that's the case then I'm forced to bin the lot and try and get the object again in a couple of weeks time.
Appreciate again your time and efforts.
Cheers.