Strange image corruption



I’ve been using SGP as a trial with my new camera and occasionally I’ll have a few saved like the following. I look through the forum but didn’t spot anything similar.

As you can see, the left and right side is swapped. And the new left side looks dropped down by 1 pixel. Strange, no?

From what I can remember, this has only appeared when I’ve been clicking backwards to review previous images, sometimes quickly, at the same time the imaging sequence is running. It could be related to when I’m clicking backwards while it’s trying to display a new photo that was just downloaded. I’m not sure. It never seemed to show a bad image as the sequence was running, just when I’ve tried to click backwards.

I’m using a QSI 690 & Windows 8.1. Latest QSI drivers. I am using SGP – but I should note that I did see this a few weeks ago and ignored it at the time when using the released 2.3 version.




Could these images have been taken on opposite sides of the meridian?



So, is it the preview display of images that is messed up or the actual image on disk? When you open a FITs (outside of SGPro) that shows like this in SGPro does it also look like this or is it normal?


Disregard my previous comment. I was thinking that it was 2 images side by side and not a single image from the camera.



Yes, it’s a single image and is saved to disk as you see it (my jpg is stretched and resized, though). I can provide the original fits if that helps.

90% of the images come out fine, just once in a while I see one or two like this and it seems (I stress seems) it only happens after I’ve clicked back a bunch of times while SGP is still running the sequence (in the middle of exposing or downloading or attempting to display after a download). I haven’t noticed any issue when SGP is left alone while it runs a sequence. My speculation is it might occur right when it’s done downloading and getting ready to display the new image AND while I’m clicking back through older images. Though, I can’t say if it’s corrupted on first save or if something overwrites the image later.

Is there debugging/logging I can turn on to help diagnose the problem? Perhaps we could see if the file is saved twice, at a minimum?


Strange I saw this last night as well , just thought it was a one off problem
I think its a display problem as the image would solve and open ok in another program ( ok pixinsight :smile: )





That’s interesting - it’s only a display problem for you? Your images on disk are not affected?

My issue is definitely both display and affecting the image on disk.


I will check all the subs as I have not done so yet , just to make sure

But I loaded a old one up to use as a target and I know that one was fine and displayed as yours above



The file is only saved one time. I need to take a look at the image buffer state prior to save though.



I’m planning another session tonight. If there’s logging I can turn on to help us, let me know.



We have identified an issue here, but we are not 100% certain what is causing it. In the meantime, please do not open images or use the history browser in SGPro 2.4 beta (until we resolve the issue).


Did we ever find the cause of this issue and has it been corrected? I am just now getting around to processing my images from February 2015 and found about 10 % of them have this split image with the left 40 % of a normal image showing up on the right side of the image.

What is the best way to attach examples.



There is no need. This issue has been fixed for nearly 2 years. If your data is corrupt, I’m afraid there is nothing to be done.



Thanks! I was worried that it might be my camera.