Ongoing HDRMultiscaleTransform Issue

[GaryI]

I have been dealing with this issue for many months now after reading different posts in this forum related to the subject.  The issue is simple - HDRMultiscaleTransform works fine in a small preview, but often does not work at all in a larger preview or applied to the full image.  This only happens for large images and is obviously related to image size somehow.

HDRMultiscaleTransform is a great tool and it is a shame that it is compromised in this way.  If there is no fix to it, than I can accept it.  But I haven't seen any explanations for this behavior and why it can't be fixed.

I use SubstitutewithPreview as a workaround, but in some cases this is not a practical solution.

[msmythers]

Here is the explanation as to why small previews don't work with HDRMT.

https://pixinsight.com/forum/index.php?topic=8461.msg55085#msg55085


Mike

[GaryI]

Mike,

To clarify, the small preview is working great.  The problem is that it does not work for the full image.

In the thread you linked, as well as one other I have seen, it seems that people are confusing these two things, which I think is the main reason why the issue has not been addressed.

Gary

[msmythers]

Gary are saying the large preview isn't working or when you apply HDRMT to the full image?

I've attached 2 images of M81. The first is the original, no HDRMT. The second you see in the left side a small preview with HDRMT applied to the preview and to the main image. The main image is different from the preview. The right side is the same image but a large preview. Both the large preview and the whole image now agree. I am not using masks in these cases.



Mike

[RickS]

To clarify, the small preview is working great.  The problem is that it does not work for the full image.

In the thread you linked, as well as one other I have seen, it seems that people are confusing these two things, which I think is the main reason why the issue has not been addressed.

Hi Gary,

I've seen HDRMT behave differently on a small preview and the full image but I've never seen it "not work."  It always does something - for me at least, and I use it a lot.  Have you tried using a larger preview (or a preview that includes the whole image) and tweaking the parameters to see if you can get what you want?

Cheers,
Rick.

[GaryI]

A bit more clarification.

This ONLY happens to me when I have the "Median Transform" box checked, which is my preferred process.  If the preview is small enough, it works every time and I can use Substitute With Preview to apply to that area to that part of the image.  But if the preview is too large, nothing happens when I apply it in the preview (the process seems to happen, since it takes some time, but there is absolutely no change in the result , even at maximum zoomed in).  Also, nothing happens when I apply it to the full image.  This is a very repeatable process.  In fact, I can't recall any time recently when I have been apply to successfully apply this process to the entire image (My images are typically 4656 by 3520).  Last year, I don't recall having this problem at all.

I have NO problems at all if I uncheck the Median Transform box.  Then it works every time on any size image, but I don't like the result as much as when the box is checked.

I am a practical person, so if I am the only one having this problem (no one else has yet replied to this thread to say they have the same problem), then perhaps I just have a setting incorrectly set somewhere on my system and it is just my problem, so I wouldn't expect any help. 

FYI, I have a new fast gaming desktop running Windows 10 and plenty of memory, disk space, and graphics processing capability.