Bayer drizzle

Questions and answers about processing in StarTools and how to accomplish certain tasks.
Mike in Rancho
Posts: 1154
Joined: Sun Jun 20, 2021 10:05 pm
Location: Alta Loma, CA

Re: Bayer drizzle

Post by Mike in Rancho »

I saw this in some thread on CN the other day, pretty cool. He just keeps adding stuff. Now, if only I could ever learn how to use it -- other than running a pre-fab stacking script. Once you learn it (no different than you have to with DSS or ASTAP), WBPP is just so easy to set up complex stacking with its table layout, tabs, and options controls.

He did mention that release of 1.4 is nowhere close to being ready.

I read the included link, and even the link within the link, and stuff does get over my head pretty quickly. Especially his conflation of true drizzle and CFA (or Bayer) drizzle. Though PI may be similar? :confusion-shrug:

My impression has always been that "true" drizzle is essentially an upscaling, but the data rains down onto a finer grid. If you are undersampled, this can produce enhanced resolution when everything is stacked. If you aren't, then there is no recovery of resolution, though I don't know if still provides an "appearance" of being smoother or more rounded off when it comes to things like stars. :think:

True drizzle could certainly be run on OSC data. I though, maybe wrongly, that it was done post-debayering.

Bayer drizzle instead replaces debayering, using the shifts, drift, and dither to fill in the entire grid with actual captured data, in three channels across the entire image dimension. The point being to avoid artifacts inherent in various debayering algorithms, as well as just knowing that everything is a real photon. Absent any error handling that may be needed, of course.

DSS says the concepts are related, but warns that you should not do both. But maybe they are the outlier?

Perhaps it all comes down to implementation, particularly as to star registration because sub-pixel transforms are required (splining, warping?) that have to go beyond simple dX dY and rotation angle. Maybe that's why they would end up conflated or the same? :think:
dx_ron
Posts: 257
Joined: Fri Apr 16, 2021 3:55 pm

Re: Bayer drizzle

Post by dx_ron »

decay wrote: Sun May 05, 2024 7:34 am Thanks for pointing out, Ron. I'm also sure that money will be better invested in new hardware.
Instead of buying PI and supporting their monopoly (just kidding?) you could consider to make a donation to the Siril team or to buy a T-Shirt from their shop ;)

Dietmar.
I did! (make a donation - no T shirt...)
decay
Posts: 447
Joined: Sat Apr 10, 2021 12:28 pm
Location: Germany, NRW

Re: Bayer drizzle

Post by decay »

dx_ron wrote: Tue May 07, 2024 9:30 pm I did! (make a donation - no T shirt...)
:)
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