Release OriginStack 2.15.0 · hd152/originstack

Which download?

You have	Download
Windows, want it installed	`OriginStack-2.15.0-setup.exe`
Windows, no install (one file)	`OriginStack-2.15.0-windows-x64-portable.exe`
Windows, no install (folder)	`OriginStack-2.15.0-windows-x64.zip`
Mac with Apple silicon (M1 or later)	`OriginStack-2.15.0-macos-arm64.zip`
Mac with Intel	`OriginStack-2.15.0-macos-x86_64.zip`
Linux	`OriginStack-2.15.0-linux-x64.tar.gz`

Sharper multi-night combines, truer star colours in the JPEG, galaxies that keep their faint
outskirts, and lossless PNG copies of the final image.

Lossless copies of the final image: --export png and png16 (also "Also save" in the
app, remembered between launches). png is the JPEG's own image without compression (8-bit,
about 1.8x the JPEG's size); png16 is the same render in 16 bits per channel, for further
editing in another program without banding (about 6x). Both are made from the same render as
the JPEG and are rewritten when you pick another stretch after the run.
Multi-night combines keep a sharp night's detail (--merge and the multi-session
combine, on by default; --no-merge-proper restores the plain weighted mean). Each night
is weighted per spatial frequency by its own measured star profile (proper coaddition, as already done for the
frames within a night) instead of by one noise weight, so a long night of poor seeing no
longer dilutes a short sharp one. Same noise and star flux as the plain weighted mean. On a
real two-night Pleiades merge (2.8 and 6.2 px nights) stars came out 22% narrower (2.99 to
2.36 px, 400 stars) with no rings; over 24 two-night targets a median 2.6% narrower, 15% at
the 10th percentile, and unchanged where the nights' seeing matched. With
--merge-consistency the consistency combine is used instead.

Galaxies keep their faint outskirts in the preview. The galaxy preset put the preview's
black point one noise sigma above the sky; after the learned deconvolver has removed most of
the sky noise, that line sits just above the sky and took the faint outer disk and arms with
it: 51-57% of the faint galaxy pixels came out pure black on Sunflower and Sculptor, 27-29% on
Whirlpool and M101. The black point is now the sky median (12-23% black, half the sky still
black). --config preview_black_sigma=1.0 restores the old, blacker sky.

Star colours in the JPEG. Preview JPEGs stored colour at half resolution (the JPEG
encoder's default 4:2:0), so a small star's colour was averaged with the black sky around it:
on the Sunflower, Omega and Pleiades previews stars kept 61-78% of their colour saturation and
their colour error was 3x what full-resolution colour gives. All preview, viewer and
annotated JPEGs now keep colour at full resolution (stars keep 96-99%), for files 15-32%
larger. The 8-bit conversion also rounds instead of truncating, which made every pixel up to
one step darker.
One dark-scaling note per run. When the lights' exposures differ from the dark's, the log
now says so once, listing each exposure with its scale factor and frame count. Each Phase 1
worker used to print it for every exposure it met: 18 identical lines on a session of 20, 25
and 30 s lights with a 10 s dark.