Maybe a FAQ

General discussion about StarTools.
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perdrix
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Joined: Wed Sep 18, 2019 10:05 am

Maybe a FAQ

Post by perdrix »

Just started to play with Startools, and couldn't load my TIF files because I store them compressed.

Is there a particular reason that the libtiff (I assume that's what you use to read tiff files) support for compressed (Zip or LZMA) files isn't used?

Thanks
David
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Re: Maybe a FAQ

Post by admin »

Ah, yes. :) ST doesn't use libTIFF. TIFF import for datasets is more of a courtesy feature, as TIFF is an image format (implying its payload is an image), rather than a scientific data format. As such, only baseline TIFF is supported.
32-bit FITS is really the preferred input for datasets.

I can perhaps be accused of being a bit pedantic about these things. However, StarTools - more than other software - really needs the most virgin possible data you can muster for the purpose of signal Tracking. No stretching, no color balancing, no sharpening, no noise reduction; e.g. as close to raw detected photon counts as possible. This is much more likely the case for FITS data sources, but not so with TIFF image sources. With an emphasis on FITS as the preferred format and keeping TIFF support more basic, this hopefully nudges people in the right direction.

I hope these subtleties make sense!
Ivo Jager
StarTools creator and astronomy enthusiast
perdrix
Posts: 27
Joined: Wed Sep 18, 2019 10:05 am

Re: Maybe a FAQ

Post by perdrix »

admin wrote:Ah, yes. :) ST doesn't use libTIFF. TIFF import for datasets is more of a courtesy feature, as TIFF is an image format
Yes, but a FITS/Uncompressed TIF is HUGE, please could you considar adopting libtiff so those of us with limited disk space can take part too :).

PS added a few days later: The compression in TIFF files is lossless unlike most jpg comression.

Clears skies,
David
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