AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2004.02.06 21:35 "[Tiff] displaying 12 bit tiff image", by Liliana Resendiz
2004.02.09 09:00 "Re: [Tiff] displaying 12 bit tiff image", by Andrey Kiselev
2004.02.09 15:06 "Re: [Tiff] displaying 12 bit tiff image", by Bob Friesenhahn
2004.02.10 13:32 "Re: [Tiff] displaying 12 bit tiff image", by Liliana Resendiz
2004.02.10 21:41 "Re: [Tiff] displaying 12 bit tiff image", by Chris Cox
2004.02.10 22:30 "Re: [Tiff] displaying 12 bit tiff image", by Liliana Resendiz
2004.02.10 23:05 "Re: [Tiff] displaying 12 bit tiff image", by Bob Friesenhahn
2004.02.10 23:37 "Re: [Tiff] displaying 12 bit tiff image", by Frank Warmerdam
2004.02.11 00:21 "Re: [Tiff] displaying 12 bit tiff image", by Bob Friesenhahn

2004.02.10 23:37 "Re: [Tiff] displaying 12 bit tiff image", by Frank Warmerdam

The image comes from a CCD Thomson Camera (TH-8430), and it is saved on a 16-bit buffer, so the data range is [0,4095]. Finally i displayed it with libtiff libraries, but I think it can improve, i'll take a look to the DGM 1.1.

If it was saved as 16 bit/sample - then the data should have been scaled to 0..65535.

(although several companies have made the mistake of not scaling -- it is spelled out pretty clearly in the TIFF spec.)

Chris,

I would note that remote sensing sensor data is routinely distributed as 16 bits per sample, but with a dynamic range far from the complete 0..65535 range in order to preserve the original sensor results. In cases like this remote sensing applications are expected to scale the data themselves, and there are many approaches to doing that.

My point is that while a "simple picture" that is stored as 16bit might need to be pre-scaled in the TIFF file in the range 0-65535, there are respectible reasons to deliver other kinds of "scientfic data" such that this is not done. Some kinds of applications should be prepared for this to happen.

Best regards,

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