Asterism - Image preProcessing and Conversion for Linux

General discussion about StarTools.

Re: Asterism - Image preProcessing and Conversion for Linux

Postby Rowland » Mon Jun 19, 2017 6:57 am

Update: I've added a polynomial stacking routine. Essentially a noise rejection filter. Removes satellite trails and hot pixels. Before and after shots. These are low resolution jpg normalized gamma 2.2 to illustrate the effect. These are linear images - no post processing has been performed.
post-228066-0-87483800-1497825500.jpg
post-228066-0-87483800-1497825500.jpg (72.54 KiB) Viewed 125 times
post-228066-0-04502800-1497825520.jpg
post-228066-0-04502800-1497825520.jpg (60.23 KiB) Viewed 125 times
Last edited by Rowland on Mon Jun 26, 2017 9:36 pm, edited 2 times in total.
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Re: Asterism - Image preProcessing and Conversion for Linux

Postby Rowland » Sat Jun 24, 2017 2:14 am

A new version. No major changes. Largely bug fixes, code tidy up and provision for setting ImageMagick in-built resources - threads and memory - on a per-session basis. Removed unnecessary parallel processing routines, letting ImageMagick handle the resources.
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Re: Asterism - Image preProcessing and Conversion for Linux

Postby Rowland » Fri Jun 30, 2017 10:03 pm

New version and manual - minor bug fix. LLRGB has been remodelled and Bayer non-raw images can be processed. Asterism manual refers.
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Re: Asterism - Image preProcessing and Conversion for Linux

Postby Rowland » Wed Jul 05, 2017 6:54 am

Proposed addition of superbias capability. Elimination of random noise.
sbias.jpg
superbias
sbias.jpg (52.51 KiB) Viewed 89 times

For completion a median flat calibrated with the superbias
sflat.jpg
median flat
sflat.jpg (9.63 KiB) Viewed 89 times

superdark is hit and miss - median combine is appropriate for darks at most.

Asterism_superbias version may be downloaded via the web page link in my signature below.
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Re: Asterism - Image preProcessing and Conversion for Linux

Postby Rowland » Sat Jul 08, 2017 7:05 am

Added a standalone alignment and stacking utility. User manual refers.

EDIT: Documentation update
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Re: Asterism - Image preProcessing and Conversion for Linux

Postby Rowland » Sat Jul 22, 2017 3:54 am

Tweaks and bug fix. Super-bias process modified.

EDIT: this process is essentially a large kernel median filter. The larger the kernel the longer the process. Comparing histograms of various kernel sizes, the latest iteration should be a good compromise between noise reduction in the bias and processing time
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