Search found 246 matches

by dx_ron
Wed Mar 27, 2024 9:22 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

Hi Dietmar - interesting project with the plot, for sure. (and absolutely on target for the thread) (I only removed the M13 because my dropbox is nearly full) Here's how I'm currently thinking about it (but I could be completely wrong!) The real action is happening in just the first few points in th...
by dx_ron
Wed Mar 27, 2024 1:11 am
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

The answer is that re-calibrating and registering the subs as 16-bit integer files did indeed resolve the 'greater than 1' issue. Which helps explain why Ivo writes signal processing programs and I sit here and push buttons. Here, by the way, is the 1.9.565 version of the M3 data, properly calibrate...
by dx_ron
Mon Mar 25, 2024 8:54 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

I'm definitely not proposing we should be doing 16-bit stacking, however the assumption is that the source material is *multiple subs* of 10, 12, 14 or 16-bit quantized data, where values fell within the range of 0 to /1024, 4096, 16384 or 65536. Stacking multiple subs will - in essence - add 2^(st...
by dx_ron
Sun Mar 24, 2024 9:30 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

Mike in Rancho wrote: Sun Mar 24, 2024 8:40 pm Here's a quick chart with colored buckets for each pixel across the middle of the star. Interesting graphic representation of stretching, huh?
Colors! Now we're talking! Can you do one with 8x10 color glossy photographs, with circles and arrows and a paragraph on the back of each one?
by dx_ron
Sun Mar 24, 2024 9:27 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

Link to the raw single sub - https://www.dropbox.com/scl/fi/gdnc1l46c8eihc6lqwe21/M_3_AT130_45s_Light__336.fits?rlkey=sxv03qpaepnpzhm2gh061tc0t&dl=0 although it probably does not matter any more. I think 16-bit ADCs are now fairly common, with the IMX571 having become so popular, though maybe that's...
by dx_ron
Sun Mar 24, 2024 5:01 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

I was also able to "hide" it by increasing Optidev's curve resolution (the amount of points it calculates to interpolate the constructed curve between) 16-fold (from 4096/12-bit points to 65536-bit points), which should not be necessary unless something has stuffed lots of data/"detail" in a tiny (...
by dx_ron
Sun Mar 24, 2024 2:30 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

What Mike said - thank you, Ivo! Haven't had time to do much beyond download the new beta yet, but a quick look seems similar to Mike's reaction. Different, but definitely improves (cures, even?) the dark-ring effect. As for 16/32, it's a bit awkward in Siril to keep swapping back and forth (really,...
by dx_ron
Sat Mar 23, 2024 4:41 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

The plateauing can be caused by a number of things and would - as already mentioned - be chiefly caused by an area that shows comparatively very little change in co-located pixels (as a proxy for "detail"). It would therefore receive a smaller dynamic range allocation. I've seen this happen as a re...
by dx_ron
Fri Mar 22, 2024 10:41 pm
Forum: Image Processing Troubleshooting
Topic: Donut stars
Replies: 41
Views: 858

Re: Donut stars

Yes, it seems only two distinct values are assigned to the core regions of bright stars. The max value to the 'inner core' and then just one slightly lower value out for a distance surrounding it. It feels weird to realize how much time I've spent chasing an optical illusion (usually with fuzz in SV...